Transiting Exoplanet Survey Satellite

{{Short description|NASA satellite of the Explorer program}} {{Redirect|TESS||Tess (disambiguation){{!}}Tess}} {{Update|date=January 2022}} {{Use American English|date=December 2021}} {{Use dmy dates|date=December 2021}} {{Infobox spaceflight | name = Transiting Exoplanet Survey Satellite | names_list = Explorer 95 TESS MIDEX-7 | image = TESS alone high res.jpg | image_caption = TESS satellite | image_size =

| mission_type = [[Space observatory]]<ref name="NYT-20180920"/><ref name="NYT-20180326">{{cite news|last=Overbye|first=Dennis|title=Meet Tess, Seeker of Alien Worlds |url=https://www.nytimes.com/2018/03/26/science/tess-nasa-exoplanets.html|date=March 26, 2018|newspaper=The New York Times|access-date=March 26, 2018}}</ref> | operator = [[NASA]]{{\}}[[Massachusetts Institute of Technology|MIT]] | COSPAR_ID = 2018-038A | SATCAT = 43435 | website = {{URL|tess.gsfc.nasa.gov}} {{URL|tess.mit.edu}} | mission_duration = 2 years (planned) {{time interval|18 April 2018 22:51:31|show=ymd|sep=,}} ''(in progress)''

| spacecraft = Explorer XCV | spacecraft_type = Transiting Exoplanet Survey Satellite | spacecraft_bus = [[Star Bus|LEOStar-2/750]]<ref name="Ricker2015"/> | manufacturer = [[Northrop Grumman Innovation Systems|Orbital ATK]] | launch_mass = {{cvt|362|kg}} <ref name="orb-facts">{{cite web|url=https://www.orbitalatk.com/space-systems/science-national-security-satellites/science-environment-satellites/docs/TESS_Factsheet.pdf|title=TESS: Discovering Exoplanets Orbiting Nearby Stars - Fact Sheet|publisher=Orbital ATK|date=2018|access-date=21 May 2018|archive-date=17 February 2018|archive-url=https://web.archive.org/web/20180217082603/https://www.orbitalatk.com/space-systems/science-national-security-satellites/science-environment-satellites/docs/TESS_Factsheet.pdf}}</ref> | dimensions = {{cvt|3.7|xx|1.2|xx|1.5|m}} | power = 530 [[watt]]s

| launch_date = 18 April 2018, 22:51:30 [[Coordinated Universal Time|UTC]]<ref name="nsf20180418">{{cite news|url=https://www.nasaspaceflight.com/2018/04/tess-launch-mission-search-near-earth-exoplanets/ |title=SpaceX successfully launches TESS on a mission to search for near-Earth exoplanets|publisher=NASASpaceFlight.com|first=Chris|last=Gebhardt|date=April 18, 2018|access-date=May 20, 2018}}</ref> | launch_rocket = [[Falcon 9 Block 4]] [[List of Falcon 9 first-stage boosters#B1045|B1045-1]] | launch_site = [[Cape Canaveral Space Force Station|Cape Canaveral]], [[Cape Canaveral Space Launch Complex 40|SLC-40]] | launch_contractor = [[SpaceX]]

| entered_service = 25 July 2018 | deactivated = | last_contact = | decay_date =

| orbit_reference = [[Geocentric orbit]] | orbit_regime = [[Highly elliptical orbit]] | orbit_periapsis = {{cvt|362600|km}} | orbit_apoapsis = {{cvt|405400|km}} | orbit_inclination = 5.145° | orbit_period = 27.322 days | apsis = gee

| instruments =

| insignia = TESS logo (transparent bg).png | insignia_caption = TESS satellite mission patch | insignia_size = 200px

| programme = [[Explorer program]] | previous_mission = [[Interface Region Imaging Spectrograph|IRIS]] (Explorer 94) | next_mission = [[Ionospheric Connection Explorer|ICON]] (Explorer 96) }}

'''Transiting Exoplanet Survey Satellite''' ('''TESS''') is a [[space telescope]] for [[NASA]]'s [[Explorer program]], designed to search for [[exoplanet]]s using the [[transit method]] in an area 400 times larger than that covered by the [[Kepler (spacecraft)|Kepler]] mission.<ref name="Ricker">{{cite journal|title=Transiting Exoplanet Survey Satellite|date=2014-10-24 |publisher=SPIE Digital Library|doi=10.1117/1.JATIS.1.1.014003 |last1=Ricker|first1=George R.|last2=Winn|first2=Joshua N.|last3=Vanderspek|first3=Roland|last4=Latham|first4=David W.|last5=Bakos|first5=Gáspár Á. |last6=Bean|first6=Jacob L.|last7=Berta-Thompson|first7=Zachory K.|last8=Brown|first8=Timothy M.|last9=Buchhave|first9=Lars|last10=Butler|first10=Nathaniel R.|last11=Butler|first11=R. Paul|last12=Chaplin |first12=William J.|last13=Charbonneau|first13=David|last14=Christensen-Dalsgaard|first14=Jørgen|last15=Clampin|first15=Mark|last16=Deming|first16=Drake|last17=Doty|first17=John|last18=De Lee|first18=Nathan |last19=Dressing|first19=Courtney|last20=Dunham|first20=Edward W.|last21=Endl|first21=Michael|last22=Fressin|first22=Francois|last23=Ge|first23=Jian|last24=Henning|first24=Thomas|last25=Holman|first25=Matthew J.|last26=Howard|first26=Andrew W.|last27=Ida|first27=Shigeru|last28=Jenkins|first28=Jon M.|last29=Jernigan|first29=Garrett|journal=Journal of Astronomical Telescopes, Instruments, and Systems|volume=1 |article-number=014003|bibcode=2015JATIS...1a4003R |display-authors=28|doi-access=free|arxiv=1406.0151}}</ref> It was launched on 18 April 2018, atop a [[Falcon 9]] launch vehicle and was placed into a [[Highly elliptical orbit|highly elliptical]] 13.70-day orbit around the [[Earth]].<ref name="Ricker"/><ref name="NYT-20180326"/><ref name="sfn-schedule">{{cite web|url=https://spaceflightnow.com/launch-schedule/|title=Launch Schedule|publisher=Spaceflight Now|date=February 27, 2018|access-date=February 28, 2018}}</ref>{{r|bbc-amos}}<ref name="nasa.gov">{{cite web|url=https://www.nasa.gov/press-release/nasa-planet-hunter-on-its-way-to-orbit|title=NASA Planet Hunter on Its Way to Orbit|date=April 19, 2018|publisher=NASA|access-date=April 19, 2018}} {{PD-notice}}</ref> The [[First light (astronomy)|first light]] image from TESS was taken on 7 August 2018, and released publicly on 17 September 2018.<ref name="NYT-20180920"/><ref name="NASA-20180917a"/><ref name="NASA-20180917b"/>

In the two-year primary mission, TESS was expected to detect about 1,250 transiting exoplanets orbiting the targeted [[star]]s, and an additional 13,000 orbiting stars not targeted but observed.<ref>{{cite journal|last1=Barclay|first1=Thomas|last2=Pepper|first2=Joshua|last3=Quintana|first3=Elisa V.|date=2018-10-25|title=A Revised Exoplanet Yield from the Transiting Exoplanet Survey Satellite (TESS)|journal=The Astrophysical Journal|series=Supplement Series|volume=239|issue=1|page=2|doi=10.3847/1538-4365/aae3e9|arxiv=1804.05050 |bibcode=2018ApJS..239....2B|doi-access=free|issn=1538-4365}}</ref> After the end of the primary mission around 4 July 2020, scientists continued to search its data for more planets, while the [[Transiting Exoplanet Survey Satellite#Extended missions|extended missions]] acquire additional data. {{As of|2026|05|03}}, TESS had identified 7,931 candidate exoplanets, of which 885 had been confirmed.<ref>{{cite web |url=https://exoplanets.nasa.gov/tess|title=Transiting Exoplanets Survey Satellite (TESS)|work=Exoplanet Exploration: Planets Beyond our Solar System|publisher=NASA}} {{PD-notice}}</ref><ref>{{cite web |title=NASA Exoplanet Archive |url=https://exoplanetarchive.ipac.caltech.edu |website=exoplanetarchive.ipac.caltech.edu |publisher=NASA/IPAC Infrared Science Archive |access-date=2026-05-03}}</ref>

The primary mission objective for TESS was to [[Astronomical survey|survey]] the [[List of nearest bright stars|brightest stars near the Earth]] for transiting exoplanets over a two-year period. The TESS satellite uses an array of wide-field cameras to perform a survey of 85% of the sky. With TESS, it is possible to study the mass, size, density and orbit of a large cohort of small planets, including a sample of [[Terrestrial planet|rocky planets]] in the [[Circumstellar habitable zone|habitable zones]] of their host stars. TESS provides prime targets for further characterization by the [[James Webb Space Telescope]] (JWST), as well as other large ground-based and space-based telescopes of the future. While previous sky surveys with ground-based telescopes have mainly detected giant exoplanets and the [[Kepler space telescope]] has mostly found planets around distant stars that are too faint for characterization, TESS finds many small planets around the nearest stars in the sky. TESS records the nearest and brightest [[main sequence star]]s hosting transiting exoplanets, which are the most favorable targets for detailed investigations.<ref name="NASA-2014">{{cite web|url=http://www.nasa.gov/sites/default/files/files/NASA_2015_Budget_Estimates.pdf|title=NASA FY 2015 President's Budget Request Summary|publisher=NASA|date=March 10, 2014}} {{PD-notice}}</ref> Detailed information about such planetary systems with [[Hot Jupiter|hot Jupiters]] makes it possible to better understand the architecture of such systems.<ref name="Wenz">{{cite journal |last1=Wenz |first1=John |title=Lessons from scorching hot weirdo-planets |journal=Knowable Magazine |publisher= Annual Reviews |date=10 October 2019 |doi=10.1146/knowable-101019-2|doi-access=free |url=https://knowablemagazine.org/article/physical-world/2019/hot-jupiter-formation-theories |access-date=4 April 2022 |language=en}}</ref><ref name="Dawson">{{cite journal |last1=Dawson |first1=Rebekah I. |last2=Johnson |first2=John Asher |title=Origins of Hot Jupiters |journal=Annual Review of Astronomy and Astrophysics |date=14 September 2018 |volume=56 |issue=1 |pages=175–221 |doi=10.1146/annurev-astro-081817-051853 |arxiv=1801.06117 |bibcode=2018ARA&A..56..175D |s2cid=119332976 }}</ref>

The program is led by the [[Massachusetts Institute of Technology]] (MIT) with [[seed funding]] from [[Google]].<ref name="chandler-2008">{{cite web|url=http://newsoffice.mit.edu/2008/mit-aims-search-earth-planets-googles-help|title=MIT aims to search for Earth-like planets with Google's help|publisher=MIT|first=David|last=Chandler|date=March 19, 2008}}</ref> On 5 April 2013, it was announced that TESS, along with the [[Neutron Star Interior Composition Explorer]] (NICER), had been selected by NASA for launch.<ref name="selection">{{cite press release|url=http://www.nasa.gov/home/hqnews/2013/apr/HQ_13-088_Astro_Explorer_Mission_.html |title=NASA Selects Explorer Investigations for Formulation|publisher=NASA|first=J. D.|last=Harrington|date=April 5, 2013}} {{PD-notice}}</ref><ref name="MIT">{{cite web |url=http://newsoffice.mit.edu/2013/nasa-selects-tess-for-mission-0405|title=NASA selects MIT-led TESS project for 2017 mission|publisher=MIT|date=April 5, 2013|access-date=April 6, 2013}}</ref> On 18 July 2019, after the first year of operation, the southern portion of the survey was completed, and the northern survey was started. The primary mission ended with the completion of the northern survey on 4 July 2020, which was followed by the first extended mission. The first extended mission concluded in September 2022 and the spacecraft entered its second extended mission<ref>{{Cite web |last=Barclay |first=Thomas |title=NASA - TESS Science Support Center |url=https://heasarc.gsfc.nasa.gov/docs/tess/./pages/the-second-extended-mission.html |access-date=2022-11-04 |website=TESS |language=en }}{{Dead link|date=September 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> which should last for another three years.

== History == The concept of TESS was first discussed in 2005 by the Massachusetts Institute of Technology (MIT) and the [[Smithsonian Astrophysical Observatory]] (SAO).<ref>{{Cite journal|last1=Ricker|first1=George R. |last2=Winn|first2=Joshua N.|last3=Vanderspek|first3=Roland|last4=Latham|first4=David W.|last5=Bakos|first5=Gaspar A.|last6=Bean|first6=Jacob L.|last7=Berta-Thompson|first7=Zachory K.|last8=Brown|first8=Timothy M.|last9=Buchhave|first9=Lars|last10=Butler|first10=Nathaniel R.|last11=Butler|first11=R. Paul|date=2014-10-24|title=The Transiting Exoplanet Survey Satellite|journal=Journal of Astronomical Telescopes, Instruments, and Systems|volume=1|issue=1|article-number=014003|doi=10.1117/1.JATIS.1.1.014003|arxiv=1406.0151|bibcode=2015JATIS...1a4003R |s2cid=1342382|issn=2329-4124}}</ref> The genesis of TESS was begun during 2006, when a design was developed from private funding by individuals, Google, and [[Kavli Foundation (United States)|The Kavli Foundation]].<ref name="hist">{{cite web|url=http://tess.gsfc.nasa.gov/mission_history.html |archive-url=https://web.archive.org/web/20140729001429/http://tess.gsfc.nasa.gov/mission_history.html|archive-date=July 29, 2014|title=Mission History|work=Transiting Exoplanet Survey Satellite |publisher=NASA|access-date=October 23, 2015}} {{PD-notice}}</ref> In 2008, MIT proposed that TESS become a full NASA mission and submitted it for the [[Small Explorer program]] at [[Goddard Space Flight Center]],<ref name="hist"/> but it was not selected.<ref>{{cite web|url=http://blogs.nature.com/news/2009/06/no_smexlove_for_tess.html|title=No SMEX-love for TESS|publisher=Nature (journal)|first=Eric|last=Hand|date=June 22, 2009|access-date=October 23, 2015|archive-date=2 October 2018|archive-url=https://web.archive.org/web/20181002105013/http://blogs.nature.com/news/2009/06/no_smexlove_for_tess.html}}</ref> It was resubmitted in 2010 as an [[Explorer program]] mission, and was approved in April 2013 as a Medium Explorer mission.<ref>{{cite conference |author=George R. Ricker|author2=Joshua N. Winn|author3=Roland Vanderspek|author4=David W. Latham|author5=Gáspár Á. Bakos|author6=Jacob L. Bean|display-authors=et al.|title=Transiting Exoplanet Survey Satellite (TESS)|series=Space Telescopes and Instrumentation 2014: Optical, Infrared, and Millimeter Wave |editor=Jacobus M. Oschmann Jr|editor2=Mark Clampin|editor3=Giovanni G. Fazio|editor4=Howard A. MacEwen|book-title=Space Telescopes and Instrumentation 2014: Optical, Infrared, and Millimeter Wave |publisher=SPIE|date=2014|volume=9143|page=914320 |doi=10.1117/12.2063489|hdl=1721.1/97916|isbn=978-0-8194-9611-9|hdl-access=free}}</ref><ref name="hist"/><ref>{{cite web|url=http://explorers.gsfc.nasa.gov/midex.html |title=Medium-Class Explorers (MIDEX) Missions in Development|publisher=NASA|access-date=October 23, 2015}} {{PD-notice}}</ref> TESS passed its [[Design review (U.S. government)|critical design review]] (CDR) in 2015, allowing production of the satellite to begin.<ref name="hist"/> While Kepler had cost US$640 million at launch, TESS cost only US$200 million (plus US$87 million for launch).<ref>{{cite news |title=Meet TESS, NASA's Next Planet Finder|url=https://www.popularmechanics.com/space/telescopes/a9565/all-about-tess-nasas-next-planet-finder-16097391/|access-date=May 4, 2018|publisher=Popular Mechanics |date=October 30, 2013}}</ref><ref>{{cite news|last1=Clark|first1=Stuart|title=Spacewatch: Tess embarks on planet-hunting mission for NASA|url=https://www.theguardian.com/science/2018/apr/19/tess-nasa-planet-exoplanet-hunt-satellite|access-date=May 4, 2018|newspaper=the Guardian|date=April 19, 2018}}</ref> The mission will find exoplanets that periodically block part of the light from their host stars, events called transits. TESS will survey 200,000 of the brightest stars near the [[Sun]] to search for transiting exoplanets. TESS was launched on 18 April 2018, aboard a SpaceX Falcon 9 launch vehicle.

In July 2019, an Extended Mission 2020 to 2022 was approved.<ref>{{cite web|url=https://tess.mit.edu/news/nasa-extends-the-tess-mission/|title=NASA Extends the TESS Mission through 2022|first=Ismael |last=Mireles|date=July 18, 2019}}</ref> On 3 January 2020, NASA reported that TESS had discovered its first [[List of potentially habitable exoplanets|potentially habitable]] Earth-sized planet, [[TOI-700 d]].<ref name="NASA-20200106"/>

== Mission overview == TESS is designed to carry out the first spaceborne [[Astronomical survey|all-sky]] [[transiting exoplanet]] survey.<ref name="selection"/><ref name="Ricker2014">{{cite conference|title=Discovering New Earths and Super-Earths in the Solar Neighborhood|conference=SPIE Astronomical Telescopes + Instrumentation 22–27 June 2014 Montréal, Québec, Canada|first=George R.|last=Ricker|date=June 26, 2014 |doi=10.1117/2.3201407.18}}</ref> It is equipped with four wide-angle telescopes and associated [[charge-coupled device]] (CCD) detectors. Science data are transmitted to Earth every two weeks. Full-frame images with an effective exposure time of two hours are transmitted as well, enabling scientists to search for unexpected transient phenomena, such as the optical counterparts to [[gamma-ray burst]]s. TESS also hosts a Guest Investigator program, allowing scientists from other organizations to use TESS for their own research. The resources allocated to Guest programs allow an additional 20,000 celestial bodies to be observed.<ref>{{cite web|url=https://www.nasa.gov/content/about-tess|title=About TESS|date=July 15, 2016|publisher=NASA|access-date=March 25, 2018}} {{PD-notice}}</ref>

[[File:NASA-Tess-SouthernSkyPanorama-20190718.webm|thumb|upright=1.0|right|TESS - Southern Sky panorama {{small|(video (3:30); 18 July 2019)}}]]

=== Orbital dynamics === TESS uses a novel highly elliptical orbit around the Earth with an [[Apsis|apogee]] approximately at the distance of the Moon and a [[Apsis|perigee]] of {{cvt|108000|km}}. TESS orbits Earth twice during the time the Moon orbits once, a 2:1 [[Orbital resonance|resonance]] with the Moon.<ref name="McGiffin">{{cite journal |last1=McGiffin |first1=Daniel A. |last2=Mathews |first2=Michael |last3=Cooley |first3=Steven |date=June 1, 2001 |title=HIGH EARTH ORBIT DESIGN FOR LUNAR-ASSISTED MEDIUM CLASS EXPLORER MISSIONS |url=https://ntrs.nasa.gov/search.jsp?R=20010084964 |journal=2001 Flight Mechanics Symposium |publisher=NASA}} {{PD-notice}}</ref> The orbit is expected to remain stable for a minimum of ten years.

In order to obtain unobstructed imagery of both the [[Northern celestial hemisphere|northern]] and [[Southern Celestial Hemisphere|southern hemispheres]] of the sky, TESS utilizes a 2:1 [[Moon|lunar]] [[Orbital resonance|resonant orbit]] called P/2, an orbit that has never been used before (although [[Interstellar Boundary Explorer]] (IBEX) uses a similar P/3 orbit). The [[highly elliptical orbit]] has a {{cvt|375000|km}} apogee, timed to be positioned approximately 90° away from the position of the Moon to minimize its [[Perturbation (astronomy)|destabilizing effect]]. This orbit should remain stable for decades and will keep TESS's cameras in a stable temperature range. The orbit is entirely outside the [[Van Allen radiation belt|Van Allen belts]] to avoid radiation damage to TESS, and most of the orbit is spent far outside the belts. Every 13.70 days at its perigee of {{cvt|108000|km}}, TESS transmits the data it collected during its most recent orbit back to earth via its [[#Spacecraft|downlink]]. This transmission occurs over a period of approximately three hours.<ref>{{cite web|url=http://www.nasa.gov/content/goddard/new-explorer-mission-chooses-the-just-right-orbit/|title=New Explorer Mission Chooses the 'Just-Right' Orbit|publisher=NASA|date=31 July 2013}}</ref>

TESS's two-year all-sky survey would focus on nearby [[G-type main-sequence star|G-]], [[K-type main-sequence star|K-]], and [[Red dwarf|M]]-[[spectral type|type]] [[star]]s with [[apparent magnitude]]s brighter than magnitude 12.<ref name="seager-2011">{{cite web|url=http://seagerexoplanets.mit.edu/exoplanet.htm|title=Exoplanet Space Missions|publisher=Massachusetts Institute of Technology|first=Sara|last=Seager|date=2011|access-date=April 7, 2013|archive-date=25 November 2019|archive-url=https://web.archive.org/web/20191125135637/http://seagerexoplanets.mit.edu/exoplanet.htm}}</ref> Approximately 500,000 stars were to be studied, including the 1,000 closest [[red dwarf]]s across the whole sky,<ref name="tess-nasa-faq"/><ref name="skytel20130530">{{cite news|url=http://www.skyandtelescope.com/astronomy-news/exoplanets-after-kepler-whats-next/|title=Exoplanets After Kepler: What's next?|publisher=Sky & Telescope|first=Mark |last=Zastrow|date=May 30, 2013|access-date=December 17, 2014}}</ref> an area 400 times larger than that covered by the ''[[Kepler (spacecraft)|Kepler]]'' mission. TESS was expected to find more than 3,000 transiting exoplanet candidates, including 500 [[terrestrial planet|Earth-sized]] planets and [[super-Earth]]s.<ref name="tess-nasa-faq"/> Of those discoveries, an estimated 20 were expected to be super-Earths located in the [[habitable zone]] around a star.<ref>{{cite news|url=http://discovermagazine.com/2015/sept/14-super-earths|title=Super-Earths Might Be Our Best Bet For Finding Alien Life|publisher=Discover (magazine)|first=Adam|last=Hadhazy|date=July 23, 2015|access-date=October 23, 2015}}</ref> The stated goal of the mission was to determine the masses of at least 50 Earth-sized planets (at most 4 times Earth radius). Most detected exoplanets are expected to be between 30 and 300 light-years away.

The survey was broken up into 26 observation sectors, each sector being 24° × 96°, with an overlap of sectors at the ecliptic poles to allow additional sensitivity toward smaller and longer-period exoplanets in that region of the celestial sphere. The spacecraft will spend two 13.70-day orbits observing each sector, mapping the southern hemisphere of sky in its first year of operation and the northern hemisphere in its second year.<ref name='Home TESS'/> The cameras actually take images every 2 seconds, but all the raw images would represent much more data volume than can be stored or downlinked. To deal with this, cutouts around 15,000 selected stars (per orbit) will be [[Lucy–Hook coaddition method|coadded]] over a 2-minute period and saved on board for downlink, while full-frame images will also be coadded over a 30-minute period and saved for downlink. The actual data downlinks will occur every 13.70 days near perigee.<ref>{{cite web|url=https://heasarc.gsfc.nasa.gov/docs/tess/docs/TESS_observatory_guide_v1.1.pdf |title=TESS Observatory Guide|publisher=NASA}} {{PD-notice}}</ref> This means that during the 2 years, TESS will continuously survey 85% of the sky for 27 days, with certain parts being surveyed across multiple runs. The survey methodology was designed such that the area that will be surveyed, essentially continuously, over an entire year (351 observation days) and makes up about 5% of the entire sky, will encompass the regions of sky (near the ecliptic poles) which will be observable at any time of year with the [[James Webb Space Telescope]] (JWST).<ref>{{cite AV media|url=https://www.youtube.com/watch?v=qPL9cFg8e38&t=42m18s|title=Latest Exoplanet Results from NASA's Kepler/K2 Mission|first=Ian|last=Crossfield |series=SETI Talks 2017|minutes=42.3|date=March 27, 2017|publisher=SETI Institute}}</ref>

In October 2019, [[Breakthrough Listen]] started a collaboration with scientists from the TESS team to look for signs of advanced extraterrestrial life. Thousands of new planets found by TESS will be scanned for "technosignatures" by Breakthrough Listen partner facilities across the globe. Data from TESS monitoring of stars will also be searched for anomalies.<ref>{{cite web |url=https://breakthroughinitiatives.org/news/27|title=Breakthrough Initiatives|website=breakthroughinitiatives.org|access-date=November 12, 2019}}</ref>

=== Asteroseismology === The TESS team also plans to use a 30-minute observation cadence for full-frame images, which has been noted for imposing a hard [[Nyquist limit]] that can be problematic for [[asteroseismology]] of stars.<ref name="Murphy2015">{{cite journal|title=The potential for super-Nyquist asteroseismology with ''TESS''|journal=Monthly Notices of the Royal Astronomical Society|first=Simon J.|last=Murphy|volume=453|issue=3|pages=2569–2575|date=November 2015|doi=10.1093/mnras/stv1842|doi-access=free |bibcode=2015MNRAS.453.2569M|arxiv=1508.02717|s2cid=54578476|url=http://simonmurphy.info/images/tess_sampling.pdf|access-date=23 April 2018|archive-date=23 April 2018|archive-url=https://web.archive.org/web/20180423170101/http://simonmurphy.info/images/tess_sampling.pdf}}</ref> Asteroseismology is the science that studies the internal structure of stars by the interpretation of their frequency spectra. Different oscillation modes penetrate to different depths inside the star. The [[Kepler (spacecraft)|''Kepler'']] and [[PLATO (spacecraft)|''PLATO'']] observatories are also intended for asteroseismology.<ref>{{cite web|url=http://www.findaphd.com/search/projectdetails.aspx?PJID=63199|title=Asteroseismic data analysis with Kepler, K2, TESS and PLATO|publisher=FindaPhD.com|access-date=October 31, 2015}}</ref>

=== Extended missions === During the 27 month First Extended Mission, July 2020 to Sept 2022, data collection was slightly changed:<ref name=N-TCPM>{{Cite web|url=http://www.nasa.gov/feature/goddard2020/nasa-s-planet-hunter-completes-its-primary-mission |title=NASA's TESS Completes Primary Mission|date=August 10, 2020|publisher=NASA}} {{PD-notice}}</ref> * A new set of target stars will be selected * The number of stars monitored at 2-minute cadence was increased from 15,000 to 20,000 per observing sector. * Up to 1000 stars per sector will be monitored at a new fast 20-second cadence. * The full-frame image cadence will be increased from every 30 minutes to every 10 minutes. * The pointings and gaps in coverage will be slightly different during the extended mission. * Regions near the ecliptic (omitted in the primary mission) will be covered.

During the 3 year Second Extended Mission,<ref>{{Cite web |last=Barclay |first=Thomas |title=NASA - TESS Science Support Center |url=https://heasarc.gsfc.nasa.gov/docs/tess/./pages/the-second-extended-mission.html |access-date=2022-11-04 |website=TESS |language=en }}{{Dead link|date=September 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Sept 2022 to Nov 2025, the full-frame image cadence will be further increased from every 10 minutes to every 200 seconds, number of 2-minute cadence targets reduced to ~8000 per sector, and number of 20-second cadence targets increased to ~2000 per sector.<ref>{{Cite web |title=NASA - TESS Science Support Center |url=https://heasarc.gsfc.nasa.gov/docs/tess/second-extended.html |access-date=2023-08-27 |website=TESS |language=en |last1=Barclay |first1=Thomas }}</ref>

== Launch == [[File:TESS Mission (41512968122).jpg|thumb|[[Falcon 9]] launch vehicle carrying TESS, launching from [[Space Launch Complex 40]] at [[Cape Canaveral Space Force Station|Cape Canaveral]] in April 2018]]

In December 2014, [[SpaceX]] was awarded the contract to launch TESS in August 2017,<ref name="snews20141217">{{cite news|url=http://spacenews.com/nasa-taps-spacex-to-launch-tess-satellite|title=NASA Taps SpaceX To Launch TESS Satellite|publisher=SpaceNews|first=Brian|last=Berger|date=December 17, 2014|access-date=October 31, 2015}}</ref> for a total contract value of US$87 million.<ref name="nasa20141216">{{cite press release|url=http://www.nasa.gov/press/2014/december/nasa-awards-launch-services-contract-for-transiting-exoplanet-survey-satellite/|title=NASA Awards Launch Services Contract for Transiting Exoplanet Survey Satellite|publisher=NASA|date=December 16, 2014|access-date=December 17, 2014}}</ref> The {{cvt|362|kg}} spacecraft was originally scheduled to launch on 20 March 2018, but this was pushed back by SpaceX to allow additional time to prepare the launch vehicle and meet NASA launch service requirements.<ref name="sfn20180216">{{cite news|url=https://spaceflightnow.com/2018/02/16/exoplanet-hunting-satellite-arrives-in-florida-for-april-launch/|title=Exoplanet-hunting satellite arrives in Florida for April launch|publisher=Spaceflight Now|first=Stephen|last=Clark|date=February 16, 2018|access-date=February 28, 2018}}</ref> A static fire of the Falcon 9 rocket was completed on 11 April 2018, at approximately 18:30 UTC.<ref>{{cite tweet|number=984057626706239488|title=The @SpaceX #Falcon9 fairing for @NASA_TESS arrived over the weekend...|user=NASA_TESS|date=April 11, 2018}}</ref> The launch was postponed again from 16 April 2018,{{r|sfn-schedule}} and TESS was eventually launched on a SpaceX [[Falcon 9 Full Thrust|Falcon 9]] launch vehicle from the [[Cape Canaveral Space Launch Complex 40|SLC-40]] launch site at [[Cape Canaveral Space Force Station|Cape Canaveral Air Force Station]] (CCAFS) on 18 April 2018.{{r|bbc-amos}}<ref name="nasa.gov"/>

The Falcon 9 launch sequence included a 149-second burn by the first stage, followed by a 6-minute second stage burn. Meanwhile, the first-stage booster performed controlled-reentry maneuvers and successfully landed on the autonomous drone ship [[Autonomous spaceport drone ship#Of Course I Still Love You|''Of Course I Still Love You'']]. An experimental water landing was performed for the fairing,{{r|flight-profile}} as part of SpaceX's attempt to develop [[Falcon 9#Recovery of second stages and fairings|fairing reusability]].

After coasting for 35 minutes, the second stage performed a final 54-second burn that placed TESS into a [[Supersynchronous orbit|supersynchronous]] [[transfer orbit]] of {{cvt|200|xx|270000|km}} at an [[Orbital inclination|inclination]] of 28.50°.<ref name=flight-profile>{{cite web|title=Launch Profile - Falcon 9 - TESS|url=http://spaceflight101.com/tess/flight-profile/|publisher=Spaceflight101.com|access-date=April 22, 2018}}</ref><ref name=burns>{{cite web|title=TESS Orbit Design|url=http://spaceflight101.com/tess/tess-orbit-design/|publisher=Spaceflight101.com|access-date=April 22, 2018}}</ref> The second stage released the payload, after which the stage itself was placed in a [[heliocentric orbit]].

== Spacecraft == [[File:TESS with techs high res.jpg|thumb|upright=1.0|right|TESS spacecraft before launch]]

In 2013, [[Orbital Sciences Corporation]] received a four-year, US$75 million contract to build TESS for NASA.<ref>{{cite news|url=http://spacenews.com/35024orbital-gets-75m-to-build-tess-exoplanet-telescope/ |title=Orbital Gets $75M To Build TESS Exoplanet Telescope|publisher=SpaceNews|first=Dan|last=Leone|date=April 24, 2013|access-date=May 17, 2016}}</ref> TESS uses an Orbital Sciences [[Star Bus|LEOStar-2]] [[satellite bus]], capable of three-axis stabilization using four [[hydrazine]] thrusters plus four [[reaction wheel]]s providing better than three [[Minute and second of arc|arcsecond]] fine spacecraft pointing control. Power is provided by two single-axis [[Solar panels on spacecraft|solar arrays]] generating 400 [[watt]]s. A [[Ka band|Ka-band]] dish antenna provides a 100 [[Data-rate units|Mbit/s]] science downlink.<ref name="tess-nasa-faq"/><ref name="tess-orbital-faq">{{cite web|url=http://www.orbital.com/SatelliteSpaceSystems/Publications/TESS_factsheet.pdf|title=TESS: Discovering Exoplanets Orbiting Nearby Stars|publisher=Orbital Sciences|date=2014|access-date=December 17, 2014|id=FS011_13_2998}}</ref>

=== Operational orbit === [[File:Animation of Transiting Exoplanet Survey Satellite trajectory.gif|thumb|upright=1.0|right|Animation of Transiting Exoplanet Survey Satellite's trajectory from 18 April 2018 to 18 December 2019 {{legend2|magenta|Transiting Exoplanet Survey Satellite}}{{·}}{{legend2|RoyalBlue|[[Earth]]}}{{·}}{{legend2|Green|[[Moon]]}}]] [[File:TESS orbital maneuvers.jpg|thumb|upright=1.0|right|Planned orbital maneuvers after release from Falcon 9's second stage. Horizontal axis schematically represents longitude relative to the Moon, vertical axis is altitude. A1M = Apogee 1 manoeuvre, P1M = Perigee 1 manoeuvre, etc., TCM = trajectory correction manoeuvre (optional), PAM = period adjustment manoeuvre.]]

Once injected into the initial orbit by the Falcon 9 [[Multistage rocket|second stage]], the spacecraft performed four additional independent [[Rocket engine#Ignition|burns]] that placed it into a lunar flyby orbit.<ref>{{cite tweet|number=990743720566894594|title=Mission Update: Team decided that the second apogee maneuver (Apogee 2 maneuver (A2M)), was not necessary...|user=NASA_TESS|date=April 29, 2018}}</ref> On 17 May 2018, the spacecraft underwent a [[gravity assist]] by the Moon at {{cvt|8253.5|km}} above the surface,<ref>{{cite tweet|number=997485558283882501|title=Mission Update: #TESS successfully completed a lunar flyby... |user=NASA_TESS|date=May 18, 2018}}</ref> and performed the final period adjustment burn on 30 May 2018.<ref>{{cite tweet|number=1002603655722397696|user=NASA_TESS|title=.@NASA_TESS Mission Update: The... |date=June 1, 2018}}</ref> It achieved an orbital period of 13.65 days in the desired 2:1 resonance with the Moon, at 90° phase offset to the Moon at apogee, which is expected to be a stable orbit for at least 20 years, thus requiring very little fuel to maintain.<ref name=bbc-amos>{{cite news|url=https://www.bbc.com/news/science-environment-43790557|title=Planet-hunter launches from Florida|first=Jonathan |last=Amos|journal=BBC News|date=April 19, 2018}}</ref> The entire maneuvering phase was expected to take a total of two months, and put the craft in an eccentric orbit ({{R+|17–75|link=y}}) at a 37° inclination. The total [[delta-v]] budget for orbit maneuvers was {{cvt|215|m/s}}, which is 80% of the mission's total available reserves. If TESS receives an on-target or slightly above nominal orbit insertion by the Falcon 9, a theoretical mission duration in excess of 15 years would be possible from a consumables standpoint.<ref name=burns/>

=== Project timeline === The [[First light (astronomy)|first light]] image was made on 7 August 2018, and released publicly on 17 September 2018.<ref name="NYT-20180920">{{cite news |last=Overbye |first=Dennis |author-link=Dennis Overbye|title=NASA's TESS Starts Collecting Planets - The satellite, launched in April, has already identified at least 73 stars that may harbor exoplanets, most of them new to astronomers. |url=https://www.nytimes.com/2018/09/20/science/nasa-tess-planets.html|date=September 20, 2018|publisher=NASA|access-date=September 23, 2018}} {{PD-notice}}</ref><ref name="NASA-20180917a">{{cite news |last1=Kazmierczak|first1=Jeanette|last2=Garner|first2=Rob|title=NASA's TESS Shares First Science Image in Hunt to Find New Worlds|url=https://www.nasa.gov/feature/goddard/2018/nasa-s-tess-shares-first-science-image-in-hunt-to-find-new-worlds|date=September 17, 2018|publisher=NASA|access-date=September 23, 2018}} {{PD-notice}}</ref><ref name="NASA-20180917b">{{cite news|title=NASA's TESS Releases First Science Image |url=https://svs.gsfc.nasa.gov/13069|date=September 17, 2018|publisher=NASA|access-date=September 23, 2018}} {{PD-notice}}</ref><ref>{{cite tweet|number=997499375084556290|title=As part of camera commissioning, the #TESS science team snapped a two-second test exposure...|user=NASA_TESS|date=May 18, 2018}} {{PD-notice}}</ref>

TESS completed its commissioning phase at the end of July and the science phase officially started on 25 July 2018.<ref>{{cite web|url=https://www.nasa.gov/feature/goddard/2018/nasa-s-tess-spacecraft-starts-science-operations|title=NASA's TESS spacecraft starts science operations|website=nasa.gov|date=July 27, 2018|access-date=July 31, 2018}} {{PD-notice}}</ref>

For the first two years of operation TESS monitored both the southern (year 1) and northern (year 2) [[Celestial sphere|celestial hemispheres]]. During its nominal mission TESS tiles the sky in 26 separate segments, with a 27.4-day observing period per segment.<ref name='Home TESS'>{{cite web|url=https://tess.mit.edu/|title=Home - TESS - Transiting Exoplanet Survey Satellite|website=tess.mit.edu|access-date=April 4, 2018}}</ref> The first southern survey was completed in July 2019. The first northern survey finished in July 2020.

A 27-month First Extended mission ran until September 2022. A second extended mission will run approximately additional three years.

== Instruments == [[File:Tess infographic poster 72dpi.png|thumb|Instruments on TESS]] The sole instrument on TESS is a package of four [[Field of view|wide-field-of-view]] charge-coupled device (CCD) cameras. Each camera features four low-noise, low-power 4 megapixel CCDs created by [[MIT Lincoln Laboratory]]. The four CCDs are arranged in a 2 x 2 detector array for a total of 16 [[Pixel|megapixel]]s per camera and 16 CCDs for the entire instrument. Each camera has a 24° × 24° [[field of view]], a {{cvt|100|mm}} effective [[entrance pupil|pupil diameter]], a lens assembly with seven optical elements, and a [[band-pass filter|bandpass]] range of 600 nm (orange) to 1000 (NIR) nm.<ref name="tess-nasa-faq">{{cite web |url=http://tess.gsfc.nasa.gov/documents/TESS_FactSheet_Oct2014.pdf|archive-url=https://web.archive.org/web/20141217175407/http://tess.gsfc.nasa.gov/documents/TESS_FactSheet_Oct2014.pdf|archive-date=2014-12-17|title=TESS: Transiting Exoplanet Survey Satellite|publisher=NASA|date=October 2014|access-date=December 17, 2014|id=FS-2014-1-120-GSFC}} {{PD-notice}}</ref><ref name="Ricker2015">{{cite journal|url=http://seagerexoplanets.mit.edu/ftp/Papers/TESS2015.pdf|title=Transiting Exoplanet Survey Satellite|journal=Journal of Astronomical Telescopes, Instruments, and Systems|first1=George R.|last1=Ricker|first2=Joshua N.|last2=Winn|first3=Roland|last3=Vanderspek|display-authors=et al.|volume=1|issue=1|article-number=014003|date=January–March 2015|doi=10.1117/1.JATIS.1.1.014003|bibcode=2015JATIS...1a4003R|arxiv=1406.0151|s2cid=1342382|access-date=28 February 2018|archive-date=11 January 2020|archive-url=https://web.archive.org/web/20200111130228/http://seagerexoplanets.mit.edu/ftp/Papers/TESS2015.pdf}}</ref> The TESS lenses have a combined field of view of 24° × 96° (2300 deg2, around 5% of the entire sky) and a [[focal ratio]] of f/1.4. The ensquared energy, the fraction of the total energy of the point-spread function that is within a square of the given dimensions centered on the peak, is 50% within 15 × 15 μm and 90% within 60 × 60 μm.{{r|Ricker2015}} For comparison, Kepler's primary mission only covered an area of the sky measuring 105 deg2, though the K2 extension has covered many such areas for shorter times.

The four telescopes in the assembly each have a 10.5-cm diameter lens entrance aperture, with a f/1.4 focal ratio, with a total of seven lenses in the [[optical train]].<ref>NASA Goddard Spaceflight Center, [https://heasarc.gsfc.nasa.gov/docs/tess/the-tess-space-telescope.html Characteristics of the TESS space telescope], retrieved 13 October 2023.{{deadlink|date=November 2025}}</ref>

== Ground operations == The TESS ground system is divided between eight sites around the United States. These include [[Space Network]] and the [[Jet Propulsion Laboratory]]'s [[NASA Deep Space Network]] for command and telemetry, [[Orbital ATK]]'s Mission Operations Center, [[Massachusetts Institute of Technology]]'s Payload Operations Center, the [[Ames Research Center]]'s Science Processing Operations Center, The [[Goddard Space Flight Center]]'s Flight Dynamics Facility, the [[Smithsonian Astrophysical Observatory]]'s TESS Science Office, and the [[Space Telescope Science Institute|Mikulski Archive for Space Telescopes (MAST)]].<ref>{{cite web|url=https://tess.gsfc.nasa.gov/groundops.html|archive-url=https://web.archive.org/web/20140729002736/http://tess.gsfc.nasa.gov/groundops.html|archive-date=July 29, 2014|title=TESS Ground Operations|publisher=NASA|access-date=January 27, 2018}} {{PD-notice}}</ref>

== Stable light source for tests == One of the issues facing the development of this type of instrument is having an ultra-stable light source to test on. In 2015, a group at the [[University of Geneva]] made a breakthrough in the development of a stable light source. While this instrument was created to support ESA's [[CHEOPS]] exoplanet observatory, one was also ordered by the TESS program.<ref name="optics20151001">{{cite news |url=http://optics.org/news/6/9/50|title=Swiss group develops 'most stable light source' for satellite tests|publisher=Optics.org|first=Matthew|last=Peach|date=October 1, 2015|access-date=October 23, 2015}}</ref> Although both observatories plan to look at bright nearby stars using the transit method, CHEOPS is focused on collecting more data on known exoplanets, including those found by TESS and other survey missions.<ref name="astro20150317">{{cite news|url=http://www.astrowatch.net/2015/03/esas-cheops-satellite-pharaoh-of.html|title=ESA's CHEOPS Satellite: The Pharaoh of Exoplanet Hunting|publisher=Astro Watch|first=Tomasz|last=Nowakowski|date=March 17, 2015|access-date=October 29, 2015|archive-date=1 April 2018|archive-url=https://web.archive.org/web/20180401144545/http://www.astrowatch.net/2015/03/esas-cheops-satellite-pharaoh-of.html}}</ref>

== Results ==

[[File:TESS test image.jpg|thumb|upright=1.0|right|Test image taken before the start of science operations. The image is centered on the constellation [[Centaurus]]. In the top right corner the edge of the [[Coalsack Nebula]] can be seen. The bright star in the bottom left is [[Beta Centauri]].]] Current mission results as of 01 July 2025: 638 confirmed exoplanets discovered by TESS, with 7655 candidate-planets that are still awaiting confirmation or rejection as false positive by the [[scientific community]].<ref name="NASA Exoplanet Archive">{{cite web |title=NASA Exoplanet Archive |url=https://exoplanetarchive.ipac.caltech.edu/docs/counts_detail.html |access-date=16 October 2022 |website=exoplanetarchive.ipac.caltech.edu}}</ref>

TESS team partners include the Massachusetts Institute of Technology, the Kavli Institute for Astrophysics and Space Research, NASA's Goddard Space Flight Center, MIT's Lincoln Laboratory, Orbital ATK, NASA's Ames Research Center, the Harvard-Smithsonian Center for Astrophysics, and the [[Space Telescope Science Institute]].[[File:PIA23130-Exoplanet-LHS3844b-ArtistConcept-20190819.jpg|thumb|upright=1.0|left|<div align="center">Exoplanet [[LHS 3844 b]] (artist concept)</div>]] === C/2018 N1 === TESS started science operations on 25 July 2018.<ref name="comet">{{Cite web|url=http://www.nasa.gov/feature/goddard/2018/nasa-s-planet-hunting-tess-catches-a-comet-before-starting-science|title=Planet-Hunting TESS Catches a Comet Before Starting Science|first=Rob|last=Garner|date=August 6, 2018|website=NASA}}</ref> The first announced finding from the mission was the observation of [[comet]] [[C/2018 N1]].<ref name="comet" /> === Pi Mensae === The first exoplanet detection announcement was on 18 September 2018, announcing the discovery of a super-Earth in the [[Pi Mensae]] system orbiting the star every 6 days, adding to a known [[Super-Jupiter]] orbiting the same star every 5.9 years.<ref>{{cite journal|arxiv=1809.05967|title=TESS Discovery of a Transiting Super-Earth in the Π Mensae System|journal=The Astrophysical Journal|volume=868|issue=2 |page=L39|last1=Huang|first1=Chelsea X.|display-authors=et al.|year=2018|doi=10.3847/2041-8213/aaef91|pmid=31360431|pmc=6662726|bibcode=2018ApJ...868L..39H |doi-access=free }}</ref> === LHS 3844 b === On 20 September 2018, the discovery of an ultra-short period planet was announced, slightly larger than Earth, orbiting the red dwarf [[LHS 3844]]. With an orbital period of 11 hours, [[LHS 3844 b]] is one of the planets with the shortest known period. It orbits its star at a distance of {{cvt|932000|km}}. LHS 3844 b is also one of the closest known exoplanets to Earth, at a distance of 14.9 parsecs.<ref name="Vanderspek2018">{{cite journal|title=TESS Discovery of an ultra-short-period planet around the nearby M dwarf LHS 3844|journal=The Astrophysical Journal|volume=871|issue=2|page=L24|last=Vanderspek |first=Roland|display-authors=et al.|date=September 19, 2018|arxiv=1809.07242|doi=10.3847/2041-8213/aafb7a|s2cid=119009146 |doi-access=free |bibcode=2019ApJ...871L..24V }}</ref> === HD 202772 Ab === TESS's third discovered exoplanet is [[HD 202772 Ab]], a hot Jupiter orbiting the brighter component of the visual binary star [[HD 202772]], located in the constellation [[Capricornus (constellation)|Capricornus]] at a distance of about 480 light-years from Earth. The discovery was announced on 5 October 2018. HD 202772 Ab orbits its host star once every 3.3 days. It is an inflated hot Jupiter, and a rare example of hot Jupiters around evolved stars. It is also one of the most strongly irradiated planets known, with an equilibrium temperature of {{cvt|2100|K|C F}}.<ref name="Wang2018">{{cite journal |author1=Wang, Songhu|display-authors=et al.|title=HD 202772 Ab: A Transiting Hot Jupiter Around A Bright, Mildly Evolved Star In A Visual Binary Discovered By Tess|journal=The Astronomical Journal|volume=157 |issue=2|page=51|arxiv=1810.02341|date=October 5, 2018|doi=10.3847/1538-3881/aaf1b7|s2cid=59499230 |doi-access=free }}</ref> === HD 21749 === On 15 April 2019, TESS' first discovery of an earth-sized planet was reported. [[HD 21749 c]] is a planet described as "likely rocky", with about 89% of Earth's diameter and orbits the [[K-type main-sequence star|K-type main sequence star]] [[HD 21749]] in about 8 days. The planet's surface temperature is estimated to be as high as 427 °C. Both known planets in the system, [[HD 21749 b]] and [[HD 21749 c]], were discovered by TESS. HD 21749 c represents the 10th confirmed planet discovery by TESS.<ref>{{cite web|url=http://www.nasa.gov/feature/goddard/2019/nasa-s-tess-discovers-its-first-earth-size-planet|title=NASA's TESS Discovers its First Earth-size Planet|last=Garner|first=Rob|date=April 15, 2019|publisher=NASA|access-date=April 20, 2019}} {{PD-notice}}</ref> === MAST Data collaboration === Data on exoplanet candidates continue to be made available at MAST.<ref>{{cite web|url=https://archive.stsci.edu/prepds/tess-data-alerts/|title=TESS-DATA-ALERTS: Data Products From TESS Data Alerts |website=archive.stsci.edu|access-date=April 20, 2019}}</ref> As of 20 April 2019, the total number of candidates on the list was up to 335. Besides candidates identified as previously discovered exoplanets, this list also includes ten newly discovered exoplanets, including the five mentioned above. Forty-four of the candidates from Sector 1 in this list were selected for follow-up observations by the TESS Follow-Up Program (TFOP), which aims to aid the discovery of 50 planets with a planetary radius of ''R'' < 4 [[Earth radius|''R''E]] through repeated observations.<ref>{{cite web |url=https://tess.mit.edu/followup/|title=Followup|website=TESS - Transiting Exoplanet Survey Satellite|access-date=April 20, 2019}}</ref> The list of candidate exoplanets continues to grow as additional results are being published on the same MAST page. === Changing to the Northern Sky === On 18 July 2019, after the first year of operation the southern portion of the survey was completed, it turned its cameras to the Northern Sky. As of this time it has discovered 21 planets and has over 850 candidate exoplanets.<ref>[https://www.nasa.gov/feature/goddard/2019/nasa-s-tess-mission-completes-first-year-of-survey-turns-to-northern-sky NASA.gov] NASA's TESS Mission Completes First Year of Survey, Turns to Northern Sky {{PD-notice}}</ref>

=== DS Tucanae Ab === On 23 July 2019, the discovery of the young exoplanet [[HD 222259#Planetary System|DS Tucanae Ab]] (HD 222259 Ab) in the ~45 Myr old [[Tucana-Horologium association|Tucana-Horologium]] young [[moving group]] was published in a paper. TESS first observed the planet in November 2018 and it was confirmed in March 2019. The young planet is larger than Neptune, but smaller than Saturn. The system is bright enough to follow up with radial velocity and transmission spectroscopy.<ref>{{cite web|url=https://news.dartmouth.edu/news/2019/08/dartmouth-astronomer-leading-discovery-new-planet|title=Dartmouth Astronomer on Leading Discovery of a New Planet|last=Albright|first=Charlotte|date=August 14, 2019|website=news.dartmouth.edu|access-date=November 16, 2019}}</ref><ref>{{cite journal|last1=Newton|first1=Elisabeth R.|last2=Mann |first2=Andrew W.|last3=Tofflemire|first3=Benjamin M.|last4=Pearce|first4=Logan|last5=Rizzuto|first5=Aaron C.|last6=Vanderburg|first6=Andrew|last7=Martinez|first7=Raquel A.|last8=Wang|first8=Jason J. |last9=Ruffio|first9=Jean-Baptiste|last10=Kraus|first10=Adam L.|last11=Johnson|first11=Marshall C.|date=July 23, 2019|title=TESS Hunt for Young and Maturing Exoplanets (THYME): A Planet in the 45 Myr Tucana–Horologium Association|journal=The Astrophysical Journal|volume=880|issue=1|pages=L17|arxiv=1906.10703|doi=10.3847/2041-8213/ab2988|bibcode=2019ApJ...880L..17N|s2cid=195658207|issn=2041-8213 |doi-access=free }}</ref> ESA's [[CHEOPS]] mission will observe the transits of the young exoplanet DS Tuc Ab. A team of scientists got 23.4 orbits approved in the first Announcement of Opportunity (AO-1) for the CHEOPS Guest Observers (GO) Programme to characterize the planet.<ref>{{cite web|url=https://www.cosmos.esa.int/web/cheops-guest-observers-programme/ao-1-programmes|title=AO-1 Programmes - CHEOPS Guest Observers Programme - Cosmos |website=cosmos.esa.int|access-date=November 16, 2019}}</ref> === Gliese 357 === On 31 July 2019, the discovery of exoplanets around the M-type dwarf star [[Gliese 357]] at a distance of 31 light years from Earth was announced.<ref name=":0">{{cite web |url=http://www.nasa.gov/feature/goddard/2019/confirmation-of-toasty-tess-planet-leads-to-surprising-find-of-promising-world|title=NASA's TESS Helps Find Intriguing New World|last=Garner|first=Rob|date=July 30, 2019|publisher=NASA|access-date=July 31, 2019}} {{PD-notice}}</ref> TESS directly observed the transit of [[GJ 357 b]], a hot earth with an equilibrium temperature of around 250 °C. Follow-up ground observations and analyses of historic data lead to the discovery of [[GJ 357 c]] and [[GJ 357 d]]. While GJ 357 b and GJ 357 c are too close to the star to be habitable, GJ 357 d resides at the outer edge of the star's [[habitable zone]] and may possess habitable conditions if it has an atmosphere. With at least 6.1 [[Earth mass|<var>M</var>E]] it is classified as a [[Super-Earth]].<ref name=":0"/> === Count of exoplanets in 2019 === As of September 2019, over 1000 ''TESS Objects of Interest'' (''ToI'') have been listed in the public database,<ref>{{cite web|url=https://exofop.ipac.caltech.edu/tess/view_toi.php|title=ExoFOP |website=exofop.ipac.caltech.edu}}</ref> at least 29 of which are confirmed planets, about 20 of which within the stated goal of the mission of Earth-sized (<4 Earth radii).<ref>{{cite web |url=https://tess.mit.edu/publications/|title=Publications}}</ref> === ASASSN-19bt === On 26 September 2019, it was announced that TESS observed its first [[tidal disruption event]] (TDE), called [[ASASSN-19bt]]. The TESS data revealed that ASASSN-19bt began to brighten on 21 January 2019, ~8.3 days before the discovery by [[All Sky Automated Survey for SuperNovae|ASAS-SN]].<ref>{{cite web|url=http://www.nasa.gov/feature/goddard/2019/nasa-s-tess-mission-spots-its-1st-star-shredding-black-hole |title=TESS Spots Its 1st Star-shredding Black Hole|last=Garner|first=Rob|date=September 25, 2019|publisher=NASA|access-date=November 16, 2019}} {{PD-notice}}</ref><ref>{{cite journal|last1=Holoien |first1=Thomas W.-S.|last2=Vallely|first2=Patrick J.|last3=Auchettl|first3=Katie|last4=Stanek|first4=K. Z.|last5=Kochanek|first5=Christopher S.|last6=French|first6=K. Decker|last7=Prieto|first7=Jose L. |last8=Shappee|first8=Benjamin J.|last9=Brown|first9=Jonathan S.|last10=Fausnaugh|first10=Michael M.|last11=Dong|first11=Subo|date=September 26, 2019|title=Discovery and Early Evolution of ASASSN-19bt, the First TDE Detected by TESS|journal=The Astrophysical Journal|volume=883|issue=2|page=111|arxiv=1904.09293|doi=10.3847/1538-4357/ab3c66|bibcode=2019ApJ...883..111H|s2cid=128307681|issn=1538-4357 |doi-access=free }}</ref> === TOI-700 === {{multiple image|header=TOI-700 system|align=right|caption_align=center|direction=vertical|width= |image1=PIA23407-TOI700-PlanetarySystem.jpg|caption1=TOI-700 multiplanetary system|width1=300 |image2=PIA23408-Exoplanet-TOI700d-20200106.jpg|caption2=Exoplanet [[TOI-700 d]] (artist concept)|width2=300|footer= }} On 6 January 2020, NASA reported the discovery of [[TOI-700 d]], the first [[Terrestrial planet|Earth-sized]] [[exoplanet]] in the [[Planetary habitability|habitable zone]] discovered by the TESS. The exoplanet orbits the star [[TOI-700]] 100 light-years away in the [[Dorado (constellation)|Dorado]] [[constellation]].<ref name="NASA-20200106">{{cite news|last1=Andreolo|first1=Claire|last2=Cofield|first2=Calla |last3=Kazmierczak|first3=Jeanette|title=NASA Planet Hunter Finds Earth-Size Habitable-Zone World|url=https://www.jpl.nasa.gov/news/news.php?feature=7569|date=January 6, 2020|publisher=NASA|access-date=January 6, 2020}} {{PD-notice}}</ref> The TOI-700 system contains two other planets: TOI-700 b, another Earth-sized planet, and TOI-700 c, a super-Earth. This system is unique in that the larger planet is found between the two smaller planets. It is currently unknown how this arrangement of planets came to be, whether these planets formed in this order or if the larger planet [[Planetary migration|migrated]] to its current orbit.<ref>{{cite web|url=https://aasnova.org/2020/02/18/the-tess-missions-first-earth-like-planet-found-in-an-interesting-trio/|title=The TESS Mission's First Earth-Like Planet Found in an Interesting Trio |website=aasnova.org|date=18 February 2020 |access-date=2020-02-28}}</ref> On the same day, NASA announced that astronomers used TESS data to show that [[Alpha Draconis]] is an [[eclipsing binary star]].<ref>{{cite web |url=http://www.nasa.gov/feature/goddard/2020/surprise-tess-shows-ancient-north-star-undergoes-eclipses|title=TESS Shows Ancient North Star Undergoes Eclipses|last=Reddy|first=Francis|date=January 6, 2020 |publisher=NASA|access-date=January 9, 2020}} {{PD-notice}}</ref>

=== TOI-1338 === NASA also announced the discovery of [[TOI-1338 b]], the first [[circumbinary planet]] discovered by TESS. TOI-1338 b is around 6.9 times larger than Earth, or between the sizes of [[Neptune]] and [[Saturn]]. It lies in a system 1,300 light-years away in the constellation [[Pictor]]. The stars in the system make an eclipsing binary, which occurs when the stellar companions circle each other in our plane of view. One is about 10% more massive than the Sun, while the other is cooler, dimmer and only one-third the Sun's mass. TOI-1338 b's transits are irregular, between every 93 and 95 days, and vary in depth and duration thanks to the orbital motion of its stars. TESS only sees the transits crossing the larger star — the transits of the smaller star are too faint to detect. Although the planet transits irregularly, its orbit is stable for at least the next 10 million years.<ref>{{cite web|url=http://www.nasa.gov/feature/goddard/2020/nasa-s-tess-mission-uncovers-its-1st-world-with-two-stars|title=TESS Discovers Its 1st Planet Orbiting 2 Stars|date=January 6, 2020|publisher=NASA|access-date=January 9, 2020}} {{PD-notice}}</ref>

=== HD 108236 === On 25 January 2021, a team led by astrochemist [[Tansu Daylan]], with the help of two high school interns as part of the Science Research Mentoring Program at Harvard & MIT, discovered and validated four extrasolar planets — composed of one super-Earth and three [[sub-Neptune]]s - hosted by the bright, nearby, Sun-like star [[HD 108236]]. The two high schoolers, 18 year old Jasmine Wright of [[Bedford High School (Massachusetts)|Bedford High School]] in [[Bedford, Massachusetts]], and 16 year old Kartik Pinglé of Cambridge Ringe And Latin School, of [[Cambridge, Massachusetts]], are reported to be the youngest individuals in history to discover a planet, let alone four.<ref>{{cite journal |title=TESS Discovery of a Super-Earth and Three Sub-Neptunes Hosted by the Bright, Sun-like Star HD 108236|last=Daylan|first=Tansu |date=January 25, 2021|journal=The Astronomical Journal|volume=161|issue=2|page=85|doi=10.3847/1538-3881/abd73e|arxiv=2004.11314|bibcode=2021AJ....161...85D|hdl=1721.1/134442.2 |s2cid=216080635|doi-access=free }}</ref><ref>{{cite web|url=https://news.harvard.edu/gazette/story/2021/01/high-school-students-discover-exoplanets-during-mentoring-program|title=High schoolers discover four exoplanets through Harvard & Smithsonian mentorship program|date=January 28, 2021|newspaper=The Harvard Gazette|access-date=May 30, 2021}}</ref> === TIC 168789840 === On 27 January 2021, several news agencies reported that a team using TESS had determined that [[TIC 168789840]], a stellar system with six stars in three binary pairs was oriented so astronomers could observe the eclipses of all the stars.<ref name=Nasa2021-01-27/><ref name=SciNews2021-01-25/><ref name=Forbes2021-01-28/><ref name=Wion2021-01-28/><ref name=nytimes2021-01-23/> It is the first six star system of its kind. === Count of exoplanets in 2021 === In March 2021, NASA announced that TESS found 2200 exoplanet candidates.<ref>{{cite news|url=https://exoplanets.nasa.gov/news/1677/space-telescope-delivers-the-goods-2200-possible-planets/|title=Space Telescope Delivers the Goods: 2,200 Possible Planets|publisher=NASA|date=March 23, 2021|access-date=March 24, 2021}} {{PD-notice}}</ref> By the end of 2021, TESS had discovered over 5000 candidates.<ref>{{cite web | url=https://tess.mit.edu/news/tess-science-office-at-mit-hits-milestone-of-5000-exoplanet-candidates/ | title=TESS Science Office at MIT hits milestone of 5,000 exoplanet candidates | date=21 December 2021 }}</ref> === TOI-1231 b === On 17 May 2021, an international team of scientists, including researchers from NASA's Jet Propulsion Laboratory and the [[University of New Mexico]], reported, and confirmed by a ground based telescope, the space telescope's first discovery of a Neptune-sized exoplanet, TOI-1231 b, inside a habitable zone. The planet orbits a nearby red dwarf star, 90 light-years away in the [[Vela (constellation)|Vela]] constellation.<ref name="BurtDragomirMollièreYoungblood2021">{{cite journal|last1=Burt|first1=Jennifer A.|last2=Dragomir|first2=Diana|last3=Mollière|first3=Paul |last4=Youngblood|first4=Allison|last5=Muñoz|first5=Antonio García|last6=McCann|first6=John|last7=Kreidberg|first7=Laura|last8=Huang|first8=Chelsea X.|last9=Collins|first9=Karen A.|last10=Eastman|first10=Jason D.|last11=Abe|first11=Lyu|last12=Almenara|first12=Jose M.|last13=Crossfield|first13=Ian J. M.|last14=Ziegler|first14=Carl|last15=Rodriguez|first15=Joseph E.|last16=Mamajek|first16=Eric E.|last17=Stassun |first17=Keivan G.|last18=Halverson|first18=Samuel P.|last19=Villanueva|first19=Steven Jr.|last20=Butler|first20=R. Paul|last21=Wang|first21=Sharon Xuesong|last22=Schwarz|first22=Richard P.|last23=Ricker |first23=George R.|last24=Vanderspek|first24=Roland|last25=Latham|first25=David W.|last26=Seager|first26=S.|last27=Winn|first27=Joshua N.|last28=Jenkins|first28=Jon M.|last29=Agabi|first29=Abdelkrim |last30=Bonfils|first30=Xavier|last31=Ciardi|first31=David|last32=Cointepas|first32=Marion|last33=Crane|first33=Jeffrey D.|last34=Crouzet|first34=Nicolas|last35=Dransfield|first35=Georgina|last36=Feng |first36=Fabo|last37=Furlan|first37=Elise|last38=Guillot|first38=Tristan|last39=Gupta|first39=Arvind F.|last40=Howell|first40=Steve B.|last41=Jensen|first41=Eric L. N.|last42=Law|first42=Nicholas|last43=Mann |first43=Andrew W.|last44=Marie-Sainte|first44=Wenceslas|last45=Matson|first45=Rachel A.|last46=Matthews|first46=Elisabeth C.|last47=Mékarnia|first47=Djamel|last48=Pepper|first48=Joshua|last49=Scott |first49=Nic|last50=Shectman|first50=Stephen A.|last51=Schlieder|first51=Joshua E.|last52=Schmider|first52=François-Xavier|last53=Stevens|first53=Daniel J.|last54=Teske|first54=Johanna K.|last55=Triaud |first55=Amaury H. M. J.|last56=Charbonneau|first56=David|last57=Berta-Thompson|first57=Zachory K.|last58=Burke|first58=Christopher J.|last59=Daylan|first59=Tansu|last60=Barclay|first60=Thomas|last61=Wohler |first61=Bill|last62=Brasseur|first62=C. E.|display-authors=4|title=TOI-1231b: A Temperate, Neptune-sized Planet Transiting the Nearby M3 Dwarf NLTT 24399|journal=The Astronomical Journal|arxiv=2105.08077 |date=2021-05-17|volume=162|issue=3|page=87|doi=10.3847/1538-3881/ac0432|bibcode=2021AJ....162...87B|s2cid=234763319 |doi-access=free }}</ref>

=== Exoplanet search programs === The TESS Objects of Interest (TOI) are assigned by the TESS team<ref name=":1">{{Cite journal |last1=Guerrero |first1=Natalia M. |last2=Seager |first2=S. |last3=Huang |first3=Chelsea X. |last4=Vanderburg |first4=Andrew |last5=Garcia Soto |first5=Aylin |last6=Mireles |first6=Ismael |last7=Hesse |first7=Katharine |last8=Fong |first8=William |last9=Glidden |first9=Ana |last10=Shporer |first10=Avi |last11=Latham |first11=David W. |last12=Collins |first12=Karen A. |last13=Quinn |first13=Samuel N. |last14=Burt |first14=Jennifer |last15=Dragomir |first15=Diana |date=2021-06-01 |title=The TESS Objects of Interest Catalog from the TESS Prime Mission |journal=The Astrophysical Journal Supplement Series |volume=254 |issue=2 |page=39 |doi=10.3847/1538-4365/abefe1 |arxiv=2103.12538 |bibcode=2021ApJS..254...39G |issn=0067-0049|doi-access=free }}</ref> and the Community TOIs (CTOI) are assigned by independent researchers.<ref>{{Cite web |title=ExoFOP Help page |url=https://exofop.ipac.caltech.edu/tess/help.php |access-date=2022-09-08 |website=exofop.ipac.caltech.edu}}</ref> The primary mission of TESS produced 2241 TOIs.<ref name=":1" /> Other small and large collaborations of researchers try to confirm the TOIs and CTOIs, or try to find new CTOIs.

Some of the collaborations with names that are searching exclusively for TESS planets are:

* The [[citizen science]] project [[Planet Hunters#Planet Hunters TESS (PHT)|Planet Hunters: TESS]] (PHT)<ref>{{Cite web |title=NASA/ADS, search Planet Hunters TESS |url=https://ui.adsabs.harvard.edu/search/q=title:%22planet%20hunters%20tess%22%20abstract:%22TESS%22&sort=date%20desc,%20bibcode%20desc&p_=0 |access-date=2022-09-08 |website=ui.adsabs.harvard.edu}}</ref> * [[TESS Hunt for Young and Maturing Exoplanets]] (THYME)<ref>{{Cite web |title=NASA/ADS, search for THYME |url=https://ui.adsabs.harvard.edu/search/p_=0&q=TESS%20Hunt%20for%20Young%20and%20Maturing%20Exoplanets&sort=date%20desc,%20bibcode%20desc |access-date=2022-09-08 |website=ui.adsabs.harvard.edu}}</ref> * [[The TESS-Keck Survey]] (TKS)<ref>{{Cite web |title=NASA/ADS, searching The TESS-Keck Survey or TKS |url=https://ui.adsabs.harvard.edu/search/q=(title%3A%22The%20TESS-Keck%20Survey%22%20OR%20(title%3A%22TKS%22%20AND%20abstract%3A%22TESS%22))%20NOT%20title%3A%22vizieR%22&sort=date%20desc%2C%20bibcode%20desc&p_=0 |access-date=2022-09-08 |website=ui.adsabs.harvard.edu}}</ref> * [[TESS Giants Transiting Giants]] (TESS GTG)<ref>{{Cite web |title=NASA/ADS searching TESS Giants Transiting Giants |url=https://ui.adsabs.harvard.edu/search/q=title:%22TESS%20Giants%20Transiting%20Giants%22&sort=date%20desc,%20bibcode%20desc&p_=0 |access-date=2022-09-08 |website=ui.adsabs.harvard.edu}}</ref>

Collaborations with currently a smaller amount of discovery papers:

* [[Warm gIaNts with tEss collaboration]] (WINE)<ref>{{Cite web |title=NASA/ADS, search for WINE |url=https://ui.adsabs.harvard.edu/search/q=title:%22wine%22%20abstract:%22TESS%22&sort=date%20desc,%20bibcode%20desc&p_=0 |access-date=2022-09-08 |website=ui.adsabs.harvard.edu}}</ref> * The [[TESS Grand Unified Hot Jupiter Survey]]<ref>{{Cite web |title=NASA/ADS, searching TESS Grand Unified Hot Jupiter Survey |url=https://ui.adsabs.harvard.edu/search/q=title:%22TESS%20Grand%20Unified%20Hot%20Jupiter%20Survey%22&sort=date%20desc,%20bibcode%20desc&p_=0 |access-date=2022-09-08 |website=ui.adsabs.harvard.edu}}</ref>

The TESS community is also producing [[software]] and programs to help validate the planet candidates, such as TRICERATOPS,<ref>{{Cite journal |last1=Giacalone |first1=Steven |last2=Dressing |first2=Courtney D. |last3=Jensen |first3=Eric L. N. |last4=Collins |first4=Karen A. |last5=Ricker |first5=George R. |last6=Vanderspek |first6=Roland |last7=Seager |first7=S. |last8=Winn |first8=Joshua N. |last9=Jenkins |first9=Jon M. |last10=Barclay |first10=Thomas |last11=Barkaoui |first11=Khalid |last12=Cadieux |first12=Charles |last13=Charbonneau |first13=David |last14=Collins |first14=Kevin I. |last15=Conti |first15=Dennis M. |date=2021-01-01 |title=Vetting of 384 TESS Objects of Interest with TRICERATOPS and Statistical Validation of 12 Planet Candidates |journal=The Astronomical Journal |volume=161 |issue=1 |page=24 |doi=10.3847/1538-3881/abc6af |arxiv=2002.00691 |bibcode=2021AJ....161...24G |issn=0004-6256|doi-access=free }}</ref> DAVE,<ref>{{Cite journal |last1=Kostov |first1=Veselin B. |last2=Mullally |first2=Susan E. |last3=Quintana |first3=Elisa V. |last4=Coughlin |first4=Jeffrey L. |last5=Mullally |first5=Fergal |last6=Barclay |first6=Thomas |last7=Colón |first7=Knicole D. |last8=Schlieder |first8=Joshua E. |last9=Barentsen |first9=Geert |last10=Burke |first10=Christopher J. |date=2019-03-01 |title=Discovery and Vetting of Exoplanets. I. Benchmarking K2 Vetting Tools |journal=The Astronomical Journal |volume=157 |issue=3 |page=124 |doi=10.3847/1538-3881/ab0110 |arxiv=1901.07459 |bibcode=2019AJ....157..124K |issn=0004-6256|doi-access=free }}</ref> Lightkurve,<ref>{{Cite journal |last1=Lightkurve Collaboration |last2=Cardoso |first2=José Vinícius de Miranda |last3=Hedges |first3=Christina |last4=Gully-Santiago |first4=Michael |last5=Saunders |first5=Nicholas |last6=Cody |first6=Ann Marie |last7=Barclay |first7=Thomas |last8=Hall |first8=Oliver |last9=Sagear |first9=Sheila |last10=Turtelboom |first10=Emma |last11=Zhang |first11=Johnny |last12=Tzanidakis |first12=Andy |last13=Mighell |first13=Ken |last14=Coughlin |first14=Jeff |last15=Bell |first15=Keaton |date=2018-12-01 |title=Lightkurve: Kepler and TESS time series analysis in Python |url=https://ui.adsabs.harvard.edu/abs/2018ascl.soft12013L |journal=Astrophysics Source Code Library |pages=ascl:1812.013|bibcode=2018ascl.soft12013L }}</ref> Eleanor<ref>{{Cite journal |last1=Feinstein |first1=Adina D. |last2=Montet |first2=Benjamin T. |last3=Foreman-Mackey |first3=Daniel |last4=Bedell |first4=Megan E. |last5=Saunders |first5=Nicholas |last6=Bean |first6=Jacob L. |last7=Christiansen |first7=Jessie L. |last8=Hedges |first8=Christina |last9=Luger |first9=Rodrigo |last10=Scolnic |first10=Daniel |author10-link=Daniel M. Scolnic|last11=Cardoso |first11=José Vinícius de Miranda |date=2019-09-01 |title=eleanor: An Open-source Tool for Extracting Light Curves from the TESS Full-frame Images |journal=Publications of the Astronomical Society of the Pacific |volume=131 |issue=1003 |page=094502 |doi=10.1088/1538-3873/ab291c |arxiv=1903.09152 |bibcode=2019PASP..131i4502F |issn=0004-6280|doi-access=free }}</ref> and [[Planet Patrol (project)|Planet Patrol]].<ref>{{Cite journal |last1=Kostov |first1=Veselin B. |last2=Kuchner |first2=Marc J. |last3=Cacciapuoti |first3=Luca |last4=Acharya |first4=Sovan |last5=Ahlers |first5=John P. |last6=Andrés-Carcasona |first6=Marc |last7=Brande |first7=Jonathan |last8=de Lima |first8=Lucas T. |last9=Di Fraia |first9=Marco Z. |last10=Fornear |first10=Aline U. |last11=Gallo |first11=Francesco |last12=Hyogo |first12=Michiharu |last13=Ienco |first13=Riccardo M. |last14=de Lambilly |first14=Julien S. |last15=Luca |first15=Hugo A. D. |date=2022-04-01 |title=Planet Patrol: Vetting Transiting Exoplanet Candidates with Citizen Science |url=https://ui.adsabs.harvard.edu/abs/2022PASP..134d4401K |journal=Publications of the Astronomical Society of the Pacific |volume=134 |issue=1034 |page=044401 |doi=10.1088/1538-3873/ac5de0 |bibcode=2022PASP..134d4401K |s2cid=248260172 |issn=0004-6280}}</ref>

=== Stellar rotations === TESS can estimate [[stellar rotation]] rates (which correlate with age), to find populations of similar age stars that likely formed together.<ref>[https://science.nasa.gov/missions/tess/nasas-tess-spacecraft-triples-size-of-pleiades-star-cluster/ NASA’s TESS Spacecraft Triples Size of Pleiades Star Cluster. 2025]</ref>

== In popular culture == TESS is featured accurately in the 2018 film ''[[Clara (2018 film)|Clara]]''.

== See also == {{div col}} * [[ARIEL]], 2029 exoplanet atmospheres observatory * [[CHEOPS]], 2019 exoplanet observatory * [[CoRoT]], 2006–2012 exoplanet observatory * [[Kepler space telescope|Kepler]], 2009–2018 exoplanet observatory * [[MOST (spacecraft)|MOST]], 2003–2019 asteroseismology and exoplanet observatory * [[PLATO (spacecraft)|PLATO]], 2026 exoplanet observatory * [[Sagittarius Window Eclipsing Extrasolar Planet Search|SWEEPS]], 2006 [[Hubble Space Telescope]] exoplanet survey *[[TOI-2119]] * [[List of transiting exoplanets]] {{div col end}}

== References == {{Reflist|refs=

<ref name=Nasa2021-01-27>{{cite news|url=https://exoplanets.nasa.gov/news/1672/discovery-alert-first-six-star-system-where-all-six-stars-undergo-eclipses/|title=Discovery Alert: First Six-star System Where All Six Stars Undergo Eclipses|publisher=NASA Goddard Space Flight Center|date=2021-01-27|archive-url=https://web.archive.org/web/20210127224045/https://exoplanets.nasa.gov/news/1672/discovery-alert-first-six-star-system-where-all-six-stars-undergo-eclipses/|archive-date=2021-01-27|access-date=2021-01-29|url-status=live|quote=The system, also called TIC 168789840, is the first known sextuple composed of three sets of eclipsing binaries, stellar pairs whose orbits tip into our line of sight so we observe the stars alternatively passing in front of each other.}} {{PD-notice}}</ref>

<ref name=SciNews2021-01-25>{{cite news|url=http://www.sci-news.com/astronomy/tess-sextuply-eclipsing-six-star-system-09282.html|title=TESS Discovers Sextuply-Eclipsing Six-Star System|publisher=Sci-News |author=Natali Anderson|date=2021-01-25|archive-url=https://web.archive.org/web/20210126210223/http://www.sci-news.com/astronomy/tess-sextuply-eclipsing-six-star-system-09282.html|archive-date=2021-01-26 |access-date=2021-01-29|url-status=live|quote={{'}}Prior to the discovery of TIC 168789840, there were 17 known sextuple star systems according to the June 2020 update of the Multiple Star Catalog,{{'}} lead author Dr. Brian Powell of NASA's Goddard Space Flight Center and colleagues wrote in their paper.}}</ref>

<ref name=Forbes2021-01-28>{{cite news|url=https://www.forbes.com/sites/jamiecartereurope/2021/01/28/you-should-know-about-the-weird-sextuple-star-system-just-found-by-nasa-where-six-suns-eclipse-each-other/?sh=60bfadcc7698|title=A Weird 'Sextuple' Star System Has Been Found By NASA Where Six Suns Eclipse Each Other|work=Forbes magazine|author=Jamie Carter|date=2021-01-28|archive-url=https://web.archive.org/web/20210129101812/https://www.forbes.com/sites/jamiecartereurope/2021/01/28/you-should-know-about-the-weird-sextuple-star-system-just-found-by-nasa-where-six-suns-eclipse-each-other/?sh=60bfadcc7698|archive-date=2021-01-29|access-date=2021-01-29|url-status=live}}</ref>

<ref name=Wion2021-01-28>{{cite news|url=https://www.wionews.com/science/astronomers-find-a-system-of-six-stars-made-of-three-eclipsing-binaries-359797|title=Astronomers find a system of six stars made of three eclipsing binaries|publisher=WION (TV channel)|date=2021-01-28|archive-url=https://web.archive.org/web/20210128050008/https://www.wionews.com/science/astronomers-find-a-system-of-six-stars-made-of-three-eclipsing-binaries-359797|archive-date=2021-01-28|access-date=2021-01-29|url-status=live|quote=The primary stars in all three binaries are all slightly bigger and more massive than the Sun and about as hot. The system, also called TIC 168789840, is located about 1,900 light-years away in the constellation Eridanus.}}</ref>

<ref name=nytimes2021-01-23>{{cite news|url=https://www.nytimes.com/2021/01/23/science/six-stars-eclipses.html|title=Six Stars, Six Eclipses: 'The Fact That It Exists Blows My Mind'|newspaper=The New York Times |author=Robin George Andrews|date=2021-01-23|archive-url=https://web.archive.org/web/20210128114723/https://www.nytimes.com/2021/01/23/science/six-stars-eclipses.html|archive-date=2021-01-28|access-date=2021-01-29|url-status=live|quote=But only one of the pairs could have any planets. Two of the system's binaries orbit extremely close to one another, forming their own quadruple subsystem. Any planets there would likely be ejected or engulfed by one of the four stars. The third binary is farther out, orbiting the other two once every 2,000 years or so, making it a possible exoplanetary haven.}}</ref> }}

== Further reading == {{Library resources box}} * {{cite journal|title=Transiting Exoplanet Survey Satellite|journal=Journal of Astronomical Telescopes, Instruments, and Systems|first1=George R.|last1=Ricker|first2=Joshua N.|last2=Winn|first3=Roland |last3=Vanderspek|first4=David W.|last4=Latham|first5=Gáspár Á.|last5=Bakos|first6=Jacob L.|last6=Bean|first7=Zachory K.|last7=Berta-Thompson|first8=Timothy M.|last8=Brown|first9=Lars|last9=Buchhave |first10=Nathaniel R.|last10=Butler|first11=R. Paul|last11=Butler|first12=William J.|last12=Chaplin|first13=David|last13=Charbonneau|first14=Jørgen|last14=Christensen-Dalsgaard|first15=Mark|last15=Clampin |first16=Drake|last16=Deming|first17=John|last17=Doty|first18=Nathan|last18=De Lee|first19=Courtney|last19=Dressing|first20=Edward W.|last20=Dunham|first21=Michael|last21=Endl|first22=Francois|last22=Fressin |first23=Jian|last23=Ge|first24=Thomas|last24=Henning|first25=Matthew J.|last25=Holman|first26=Andrew W.|last26=Howard|first27=Shigeru|last27=Ida|first28=Jon M.|last28=Jenkins|first29=Garrett|last29=Jernigan |first30=John Asher|last30=Johnson|first31=Lisa|last31=Kaltenegger|first32=Nobuyuki|last32=Kawai|first33=Hans|last33=Kjeldsen|first34=Gregory|last34=Laughlin|first35=Alan M.|last35=Levine|first36=Douglas |last36=Lin|first37=Jack J.|last37=Lissauer|first38=Phillip|last38=MacQueen|first39=Geoffrey|last39=Marcy|first40=Peter R.|last40=McCullough|first41=Timothy D.|last41=Morton|first42=Norio|last42=Narita |first43=Martin|last43=Paegert|first44=Enric|last44=Palle|first45=Francesco|last45=Pepe|first46=Joshua|last46=Pepper|first47=Andreas|last47=Quirrenbach|first48=Stephen A.|last48=Rinehart|first49=Dimitar |last49=Sasselov|first50=Bun'ei|last50=Sato|first51=Sara|last51=Seager|first52=Alessandro|last52=Sozzetti|first53=Keivan G.|last53=Stassun|first54=Peter|last54=Sullivan|first55=Andrew|last55=Szentgyorgyi |first56=Guillermo|last56=Torres|first57=Stephane|last57=Udry|first58=Joel|last58=Villasenor|display-authors=1|volume=1|issue=1|page=914320|date=October 24, 2014|doi=10.1117/1.JATIS.1.1.014003 |bibcode=2014SPIE.9143E..20R|arxiv=1406.0151|s2cid=1342382 }} * {{cite conference|url=http://conference.ipac.caltech.edu/wfirs2014/talks/WFIRS2014_Stassun.pdf|title=TESS and Galactic Science|conference=WFIRST Meeting|publisher=California Institute of Technology |first=Keivan|last=Stassun|date=November 18, 2014}}

== External links == {{commons category|Transiting Exoplanet Survey Satellite}} * [https://web.archive.org/web/20140303081257/https://twitter.com/NASA_TESS TESS twitter account] by NASA * [https://www.nasa.gov/tess-transiting-exoplanet-survey-satellite TESS website] by NASA Goddard * [http://tess.mit.edu/ TESS website] by Massachusetts Institute of Technology (MIT) * [https://tess.mit.edu/publications/#list_of_tess_planets TESS discovered exoplanets] by MIT * [http://www.kavlifoundation.org/science-spotlights/searching-best-and-brightest TESS website] {{Webarchive|url=https://web.archive.org/web/20180426220356/http://www.kavlifoundation.org/science-spotlights/searching-best-and-brightest |date=26 April 2018 }} by the Kavli Foundation * [https://www.zooniverse.org/projects/nora-dot-eisner/planet-hunters-tess Planet Hunters TESS]: anyone can help classifying TESS data * [https://svs.gsfc.nasa.gov/vis/a010000/a013200/a013285/ TESS listing of Southern Sky panoramas] {{Webarchive|url=https://web.archive.org/web/20191106152422/https://svs.gsfc.nasa.gov/vis/a010000/a013200/a013285/ |date=6 November 2019 }} (July 18, 2019) * [https://apod.nasa.gov/apod/ap180421.html TESS launch closeup, atop Falcon 9 rocket]. APOD (April 21, 2018) * [https://thehappykoala.github.io/Harmony-of-the-Spheres/#/category/Spacecraft/scenario/TESS Interactive 3D simulation of TESS's 2:1 lunar resonant orbit]

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