# TOI-270

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/TOI-270
> Markdown URL: https://mediated.wiki/source/TOI-270.md
> Source: https://en.wikipedia.org/wiki/TOI-270
> Source revision: 1351581668
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{Short description|Red dwarf star in the constellation Pictor}}
{{Starbox begin}}
{{Starbox observe
| epoch = [J2000](/source/J2000)
| constell = [Pictor](/source/Pictor)<ref>{{cite web |url=http://djm.cc/constellation.html |title=Finding the constellation which contains given sky coordinates |date=2 August 2008 |website=djm.cc}}</ref>
| ra = {{RA|04|33|39.72001}}<ref name="GaiaDR3"/>
| dec = {{DEC|-51|57|22.4354}}<ref name="GaiaDR3"/>
| appmag_v = 12.617<ref name="SIMBAD"/>
}}
{{Starbox character
| type = [Main sequence](/source/Main_sequence)<ref name="VanEylen2021"/>
| class = M3.0V<ref name="Günther2019"/>
| appmag_1_passband = V
| appmag_1 = {{val|12.617|0.03}}<ref name="SIMBAD"/>
| appmag_2_passband = R
| appmag_2 = {{val|12.147|0.05}}<ref name="SIMBAD"/>
| appmag_3_passband = G
| appmag_3 = {{val|11.621|0.003}}<ref name="GaiaDR3"/>
| appmag_4_passband = J
| appmag_4 = {{val|9.099|0.032}}<ref name="SIMBAD"/>
| appmag_5_passband = H
| appmag_5 = {{val|8.531|0.073}}<ref name="SIMBAD"/>
| appmag_6_passband = K
| appmag_6 = {{val|8.251|0.029}}<ref name="SIMBAD"/>
}}
{{Starbox astrometry
| radial_v           = {{val|25.90|0.37}}<ref name="GaiaDR3"/>
| prop_mo_ra         = +83.082
| prop_mo_dec        = −269.803
| pm_footnote        = <ref name="GaiaDR3"/>
| parallax           = 44.4899
| p_error            = 0.0147
| parallax_footnote  = <ref name="GaiaDR3"/>
| absmag_v           = 
| absmag_bol         = 
}}
{{Starbox detail
| source                 = <ref name="VanEylen2021"/>
| mass                   = {{val|0.386|0.008}}
| radius                 = {{val|0.378|0.011}}
| luminosity_bolometric  = {{val|0.0194|0.0019}}
| gravity                = {{val|4.872|0.026}}
| temperature            = {{val|3506|70}}
| metal_fe               = {{val|-0.20|0.12}}
| rotation               = 
| rotational_velocity    = 
| age_gyr                = 
}}
{{Starbox catalog
| names = {{odlist | 2MASS = J04333970-5157222 | L = 231-32 | PM = J04336-5157 | TIC = 259377017 | TOI = 270}}<ref name="SIMBAD"/>
}}
{{Starbox reference
| Simbad = TOI-270
| NSTED = TOI-270
}}
{{Starbox end}}

'''TOI-270''', also known as '''L 231-32''', is a [red dwarf](/source/red_dwarf) star {{convert|73.3|ly|pc|lk=on|abbr=off}} away in the constellation [Pictor](/source/Pictor). It has about 39% the mass and 38% the radius of the Sun, and a [temperature](/source/Effective_temperature) of about {{convert|3506|K|C F|lk=on}}. TOI-270 hosts a system of three known [exoplanet](/source/exoplanet)s.

==Planetary system==
The three planets of TOI-270 were discovered in 2019 by the [transit method](/source/transit_method) with [TESS](/source/Transiting_Exoplanet_Survey_Satellite).<ref name="Günther2019"/> Their masses have since been measured by both [Doppler spectroscopy](/source/Doppler_spectroscopy)<ref name="VanEylen2021"/> and [transit-timing variation](/source/transit-timing_variation)s.<ref name="Kaye2022"/> The innermost planet, TOI-270 b, is a volatile-rich [super-Earth](/source/super-Earth),<ref name="Coulombe2025" /> while the two outer planets are [mini-Neptune](/source/mini-Neptune)s.<ref name="VanEylen2021"/> TOI-270 b and c orbit near a 5:3 [resonance](/source/orbital_resonance), while TOI-270 c and d orbit near a 2:1 resonance.<ref name="Günther2019"/>

Observations of the outermost planet, TOI-270 d, by the [Hubble Space Telescope](/source/Hubble_Space_Telescope) suggest a [hydrogen](/source/hydrogen)-rich atmosphere with signs of [water vapor](/source/water_vapor).<ref name="Mikal-Evans2023"/> TOI-270 c & d are good targets for atmospheric detection with the [James Webb Space Telescope](/source/James_Webb_Space_Telescope) (JWST).<ref name="Chouqar2020"/>

It was found that TOI-270 b possibly has an atmosphere rich in water vapor based on the revised [density](/source/density) value and JWST transmission spectroscopy result.<ref name="Coulombe2025">{{cite journal |last1=Coulombe |first1=Louis-Philippe |last2=Benneke |first2=Björn |last3=Krissansen-Totton |first3=Joshua |last4=l'Heureux |first4=Alexandrine |last5=Piaulet-Ghorayeb |first5=Caroline |last6=Radica |first6=Michael |last7=Roy |first7=Pierre-Alexis |last8=Ahrer |first8=Eva-Maria |last9=Cadieux |first9=Charles |last10=Miguel |first10=Yamila |last11=Schlichting |first11=Hilke E. |last12=Delgado-Mena |first12=Elisa |last13=Monaghan |first13=Christopher |last14=Adamski |first14=Hanna |last15=Raul |first15=Eshan |last16=Cloutier |first16=Ryan |last17=Komacek |first17=Thaddeus D. |last18=Taylor |first18=Jake |last19=Gapp |first19=Cyril |last20=Allart |first20=Romain |last21=Bouchy |first21=François |last22=Canto Martins |first22=Bruno L. |last23=Cook |first23=Neil J. |last24=Doyon |first24=René |last25=Evans-Soma |first25=Thomas M. |last26=Larue |first26=Pierre |last27=Suárez Mascareño |first27=Alejandro |last28=Wardenier |first28=Joost P. |title=Possible Evidence for the Presence of Volatiles on the Warm Super-Earth TOI-270 B |journal=The Astronomical Journal |date=2025 |volume=170 |issue=4 |page=226 |doi=10.3847/1538-3881/adfc6a |doi-access=free |arxiv=2509.14224}}</ref>

{{Orbitbox planet begin
| name = TOI-270
| table_ref = <ref name="VanEylen2021"/><ref name="Kaye2022"/><ref name="Coulombe2025" />
}}
{{Orbitbox planet
| exoplanet = b
| mass_earth = {{val|1.48|0.18}}
| radius_earth = {{val|1.306|0.028}}
| semimajor = {{val|0.03197|(22)}}
| period = {{val|3.3601538|(48)}}
| eccentricity = {{val|0.0167|(84)}}
| inclination = {{val|89.41|0.43}}
}}
{{Orbitbox planet
| exoplanet = c
| mass_earth = {{val|6.20|0.31}}
| radius_earth = {{val|2.355|0.064}}
| semimajor = {{val|0.04526|(31)}}
| period = {{val|5.6605731|(31)}}
| eccentricity = {{val|0.0044|(6)}}
| inclination = {{val|89.36|0.24}}
}}
{{Orbitbox planet
| exoplanet = d
| mass_earth = {{val|4.20|0.16}}
| radius_earth = {{val|2.133|0.058}}
| semimajor = {{val|0.07210|(50)}}
| period = {{val|11.379573|(13)}}
| eccentricity = {{val|0.0066|(20)}}
| inclination = {{val|89.73|0.16}}
}}
{{Orbitbox end}}

[[File:TOI 270 v Jupiter system.jpg|thumb|700px|center|Comparison of the TOI-270 planetary system to [Jupiter's moon system](/source/Moons_of_Jupiter)<ref name="NASA-20190729"/>]]

thumb|Artist's impression of the three known planets in the TOI-270 system and their size comparison with Earth

==References==
<references>

<ref name="SIMBAD">{{cite simbad |title=L 231-32 |access-date=18 October 2023}}</ref>

<ref name="GaiaDR3">{{Cite Gaia DR3|4781196115469953024}}</ref>

<ref name="Günther2019">{{cite journal |last1=Günther |first1=Maximilian N. |last2=Pozuelos |first2=Francisco J. |display-authors=etal |date=July 2019 |title=A super-Earth and two sub-Neptunes transiting the nearby and quiet M dwarf TOI-270 |journal=[Nature Astronomy](/source/Nature_Astronomy) |volume=3 |issue= 12|pages=1099–1108 |doi=10.1038/s41550-019-0845-5 |arxiv=1903.06107 |bibcode=2019NatAs...3.1099G|s2cid=256707535 }}</ref>

<ref name="NASA-20190729">{{cite web |url=https://www.nasa.gov/universe/nasas-tess-mission-scores-hat-trick-with-3-new-worlds/ |title=NASA's TESS Mission Scores 'Hat Trick' With 3 New Worlds |last=Reddy |first=Francis |date=29 July 2019 |publisher=[NASA](/source/NASA) |access-date=18 October 2023}}</ref>

<ref name="Chouqar2020">{{cite journal |last1=Chouqar |first1=J. |last2=Benkhaldoun |first2=Z. |display-authors=etal |date=June 2020 |title=Properties of sub-Neptune atmospheres: TOI-270 system |journal=[Monthly Notices of the Royal Astronomical Society](/source/Monthly_Notices_of_the_Royal_Astronomical_Society) |volume=495 |issue=1 |pages=962–970 |doi=10.1093/mnras/staa1198 |doi-access=free |arxiv=2004.12475 |bibcode=2020MNRAS.495..962C}}</ref>

<ref name="VanEylen2021">{{cite journal |last1=Van Eylen |first1=V. |last2=Astudillo-Defru |first2=N. |display-authors=etal |date=October 2021 |title=Masses and compositions of three small planets orbiting the nearby M dwarf L231-32 (TOI-270) and the M dwarf radius valley |journal=[Monthly Notices of the Royal Astronomical Society](/source/Monthly_Notices_of_the_Royal_Astronomical_Society) |volume=507 |issue=2 |pages=2154–2173 |doi=10.1093/mnras/stab2143 |doi-access=free |arxiv=2101.01593 |bibcode=2021MNRAS.507.2154V}}</ref>

<ref name="Kaye2022">{{cite journal |last1=Kaye |first1=Laurel |last2=Vissapragada |first2=Shreyas |display-authors=etal |date=March 2022 |title=Transit Timing Variations in the three-planet system: TOI-270 |journal=[Monthly Notices of the Royal Astronomical Society](/source/Monthly_Notices_of_the_Royal_Astronomical_Society) |volume=510 |issue=4 |pages=5464–5485 |doi=10.1093/mnras/stab3483 |doi-access=free |arxiv=2308.10763 |bibcode=2022MNRAS.510.5464K}}</ref>

<ref name="Mikal-Evans2023">{{cite journal |last1=Mikal-Evans |first1=Thomas |last2=Madhusudhan |first2=Nikku |display-authors=etal |date=March 2023 |title=Hubble Space Telescope Transmission Spectroscopy for the Temperate Sub-Neptune TOI-270 d: A Possible Hydrogen-rich Atmosphere Containing Water Vapor |journal=[The Astronomical Journal](/source/The_Astronomical_Journal) |volume=165 |issue=3 |pages=84 |doi=10.3847/1538-3881/aca90b |arxiv=2211.15576 |bibcode=2023AJ....165...84M |doi-access=free }}</ref>

</references>

{{Pictor}}

Category:Pictor
Category:M-type main-sequence stars
Category:Planetary systems with three confirmed planets
0270
Category:Extraterrestrial water

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Adapted from the Wikipedia article [TOI-270](https://en.wikipedia.org/wiki/TOI-270) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/TOI-270?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.