{{Short description|Star with six sub-Neptune sized planets in the constellation Coma Berenices}} {{Use dmy dates|date=November 2023}} {{Sky|12|39|21.50369|+|20|01|40.0360|100}} {{Starbox begin | name = HD&nbsp;110067 }} {{Starbox observe | epoch = J2000 | constell = [[Coma Berenices]]<ref>{{cite constellation|HD 110067}}</ref> | ra = {{RA|12|39|21.50369}}<ref name=GaiaDR3/> | dec = {{DEC|+20|01|40.0360}}<ref name=GaiaDR3/> | appmag_v = 8.43<ref name=yoss1997/> }} {{Starbox character | type = [[Main sequence]]<ref name=GaiaDR3/> | class = K0V<ref name=yoss1997/> }} {{Starbox astrometry | radial_v = {{val|-8.56|0.13}}<ref name=GaiaDR3/> | prop_mo_ra = −81.703 | prop_mo_dec = −104.532 | pm_footnote = <ref name=GaiaDR3/> | parallax = 31.0369 | p_error = 0.0222 | parallax_footnote = <ref name=GaiaDR3/> | absmag_v = +5.96<ref name=holmberg2009/> }} {{Starbox detail | source = <ref name=Luque2023/> | mass = {{val|0.798|0.042}} | radius = {{val|0.788|0.008}} | luminosity = 0.408<ref name=reiners2020/> | gravity = {{val|4.54|0.03}} | temperature = {{val|5266|64}} | metal_fe = {{val|−0.20|0.04}} | rotation = | rotational_velocity = {{val|2.5|1.0}} | age_gyr = {{val|8.1|4.0}} }} {{Starbox catalog | names = {{odlist | BD = +20 2748 | HD = 110067 | SAO = 82424 | TIC = 347332255 | TOI = 1835 | TYC = 1448-433-1}}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = HD+110067 | NSTED = HD 110067 | EPE = HD+110067 }} {{Starbox end}}

'''HD 110067''' is a star with six known [[sub-Neptune]] [[exoplanet]]s (b, c, d, e, f, g) with radii ranging from {{earth radius|1.94|link=y}} to {{earth radius|2.85}}. The planets orbit the host star in a rhythmic [[orbital resonance]]. The star, and related planetary system, is located 105&nbsp;[[light-year]]s away in the constellation [[Coma Berenices]].<ref name=Luque2023/><ref name=SCI-20231129>{{cite news |last=Clery |first=Daniel |date=19 November 2023 |title=Astronomers stunned by six-planet system frozen in time - Undisturbed family of "sub-Neptunes" in rhythmic orbits could hold clues to planet formation |journal=[[Science (journal)|Science]] |doi=10.1126/science.ze93fui |url=https://www.science.org/content/article/astronomers-stunned-six-planet-system-frozen-time |url-status=live |access-date=19 November 2023 |archive-url=https://archive.today/20231129211552/https://www.science.org/content/article/astronomers-stunned-six-planet-system-frozen-time |archive-date=29 November 2023 }}</ref><ref name="NASA-20231129">{{cite news |last=Brennan |first=Pat |date=29 November 2023 |title=Watch the synchronized dance of a 6&nbsp;planet system |department=Discovery Alert |website=[[NASA]].gov |url=https://exoplanets.nasa.gov/news/1771/discovery-alert-watch-the-synchronized-dance-of-a-6-planet-system/ |url-status=live |access-date=29 November 2023 |archive-url=https://archive.today/20231130014226/https://exoplanets.nasa.gov/news/1771/discovery-alert-watch-the-synchronized-dance-of-a-6-planet-system/ |archive-date=30 November 2023 }}</ref><ref name=SA-20231130SK>{{cite news |last=Kathunur |first=Sharmila |date=30 November 2023 |title=Six-planet system in perfect harmony shocks scientists: Six "sub-Neptune" worlds locked in a delicate dance around a nearby star offer fresh insights for the orbital evolution of planetary systems |magazine=[[Scientific American]] |url=https://www.scientificamerican.com/article/six-planet-system-in-perfect-harmony-shocks-scientists/ |url-status=live |access-date=30 November 2023 |archiveurl=https://archive.today/20231130184222/https://www.scientificamerican.com/article/six-planet-system-in-perfect-harmony-shocks-scientists/ |archive-date=30 November 2023 }}</ref><ref name=AST-20231129>{{cite news |last=Klesman |first=Alison |date=29 November 2023 |title='Shocked and delighted': Astronomers find six planets orbiting in resonance – orbiting the brightest star ever found to host more than four planets, all have rocky or icy cores and extended atmosphere |magazine=[[Astronomy (magazine)|Astronomy]] |url=https://www.astronomy.com/science/astronomers-find-six-planets-orbiting-in-resonance/ |url-status=live |access-date=29 November 2023 |archive-url=https://archive.today/20231130010841/https://www.astronomy.com/science/astronomers-find-six-planets-orbiting-in-resonance/ |archive-date=30 November 2023 }}</ref><ref name=PBS-20231129>{{cite news |last=Dunn |first=Marcia |date=29 November 2023 |title=NASA satellites discovered a 6&nbsp;planet solar system in perfect synchrony |series=[[PBS Newshour]] |website=[[PBS]].org |url=https://www.pbs.org/newshour/science/nasa-satellites-discovered-a-6-planet-solar-system-in-perfect-synchrony |url-status=live |access-date=30 November 2023 |archive-url=https://archive.today/20231130134802/https://www.pbs.org/newshour/science/nasa-satellites-discovered-a-6-planet-solar-system-in-perfect-synchrony |archive-date=30 November 2023 }}</ref><ref name=NYT-20231129>{{cite news |last=Miller |first=Katrina |date=29 November 2023 |title=A star with six planets that orbit perfectly in sync. One hundred light years away, a handful of planets are circling a star in the same configuration as when they formed. |newspaper=[[The New York Times]] |url=https://www.nytimes.com/2023/11/29/science/star-six-planets-orbit-sync.html |url-status=live |access-date=30 November 2023 |archive-url=https://archive.today/20231129163140/https://www.nytimes.com/2023/11/29/science/star-six-planets-orbit-sync.html |archive-date=29 November 2023 }}</ref><ref name=BBC-20231129>{{cite news |last=Ghosh |first=Pallab |date=29 November 2023 |title='Perfect solar system' found in search for alien life |website=[[BBC]].com |publisher=[[BBC News]] |url=https://www.bbc.com/news/science-environment-67488931 |access-date=29 November 2023 |url-status=live |archive-url=https://archive.today/20231129212406/https://www.bbc.com/news/science-environment-67488931 |archive-date=29 November 2023 }}</ref>

HD&nbsp;110067 is part of a wide [[triple star system]], along with the [[spectroscopic binary]] system HD 110106.<ref name=Apps2023/>

==Description== HD&nbsp;110067, located 105&nbsp;[[light-years]] away in the constellation Coma Berenices, is orbited by six known sub-Neptune exoplanets (b, c, d, e, f, g) with radii ranging from {{Earth radius|1.94|link=y}} to {{Earth radius|2.85}}, and with densities (and solid cores) similar to that of [[gas giant]]s in the Solar System. None of the planets in the planetary system were found to be in the [[Planetary habitability|habitable zone]] for [[life]] as we know it.<ref name=PBS-20231129/>

==Discovery== The two innermost exoplanets orbiting HD&nbsp;110067, a bright [[K-type main-sequence star|K0-type star]], were first detected by the [[Transiting Exoplanet Survey Satellite|TESS]] ([[NASA]]) [[space telescope]], using the [[Methods of detecting exoplanets#Transit photometry|transit method]], in 2020. The remaining four exoplanets were later confirmed in 2023 as a result of additional observations using the [[CHEOPS]] ([[European Space Agency]]) space telescope.<ref name=NYT-20231129/>

==Scientific importance== On 29&nbsp;November 2023, an international team of astronomers, led by Rafael Luque, astronomer from the [[University of Chicago]], published a review of the discovery in the journal ''[[Nature (journal)|Nature]]'' entitled, "A resonant sextuplet of sub-Neptunes transiting the bright star HD&nbsp;110067".<ref name=Luque2023/> According to Luque, "It’s like looking at a fossil: The orbits of the planets today are the same as they were a billion years ago."<ref name=NYT-20231129/>

Further study of the HD&nbsp;110067 planetary system may provide a better understanding of how the pattern of the planetary orbits in the [[Solar System]] arose, which once may have begun harmoniously, but later turned chaotic. The result, possibly, of a passing star or planet or some other [[astronomical object]] capable of disrupting the nascent harmonic orbital dynamics. Additionally, further studies of the system, including compositional studies of the planetary interiors and atmospheres, may also provide a better understanding of the conditions that potentially may support [[life]].<ref name=NYT-20231129/>

[[File:StarHD110067PlanetarySystem-20231130.jpg|thumb|center|500px|The six planets in the HD&nbsp;110067 system are all smaller than Neptune, and revolve around their parent star in a very precise waltz: When the closest planet to the star makes three full revolutions around it, the second one makes exactly two during the same time; this is called a 3:2&nbsp;resonance; the six planets form a resonant chain in pairs of 3:2, 3:2, 3:2, 4:3, and 4:3, resulting in the closest planet completing six orbits while the outer-most planet does one.<ref name=SA-20231130EdL/>]] {{clear}}

==Planetary system== Six known [[sub-Neptune]] [[exoplanet]]s (b, c, d, e, f, g) with planetary radii ranging from {{earth radius|1.94|link=y}} to {{earth radius|2.85}} from HD&nbsp;110067, the host star. All planets are smaller than Neptune and have substantial atmospheres. The star and related planetary system are located 105&nbsp;light years away, in the constellation [[Coma Berenices]]. Masses of all six of the planets in the system range from {{earth mass|3.9}} to {{earth mass|8.5|link=y}}. All of the planetary orbits in the HD&nbsp;110067 system are closer to their star than distance between the planet [[Mercury (planet)|Mercury]] and the [[Sun]].<ref name=Luque2023/><ref name=SCI-20231129/>

The planets orbit the host star in synchronized rhythms of [[orbital resonance]] (a rare 1&nbsp;percent of such systems in the [[Milky Way|Milky Way galaxy]] have this symmetry): the innermost planet orbits three times for every two times for the next planet out – a so-called 3:2&nbsp;resonance; this same 3:2&nbsp;resonance also applies to the second and third planet, as well as to the third and fourth planet; whereas the fourth planet orbits four times for every three times for the fifth planet out – in a so-called 4:3&nbsp;resonance; additionally, the penultimate fifth planet orbits the sixth planet out in this same 4:3&nbsp;resonance. Further, the innermost planet completes six orbits in exactly the same time the outermost planet completes one orbit.<ref name=Luque2023/><ref name=SCI-20231129/><ref name=NASA-20231129/><ref name=SA-20231130SK/><ref name=AST-20231129/><ref name=PBS-20231129/><ref name=NYT-20231129/><ref name=BBC-20231129/> The resonance ratio for the entire system is 54:36:24:16:12:9.<ref name=Luque2023/><ref name=SCI-20231129/> {{clear}} {{Orbitbox planet begin | name = HD&nbsp;110067 | table_ref = <ref name=Luque2023/> }} {{Orbitbox planet | exoplanet = b | mass_earth = {{val|5.69|1.78|1.82}} | radius_earth = {{val|2.200|0.030}} | semimajor = {{val|0.0793|0.00096}} | period = {{val|9.113678|(10)}} | eccentricity = | inclination = {{val|89.061|0.099}} }} {{Orbitbox planet | exoplanet = c | mass_earth = <&nbsp;6.3 | radius_earth = {{val|2.388|0.036}} | semimajor = {{val|0.1039|0.0013}} | period = {{val|13.673694|(24)}} | eccentricity = | inclination = {{val|89.687|0.163}} }} {{Orbitbox planet | exoplanet = d | mass_earth = {{val|8.52|3.31|3.25}} | radius_earth = {{val|2.852|0.039}} | semimajor = {{val|0.1362|0.0017}} | period = {{val|20.519617|(40)}} | eccentricity = | inclination = {{val|89.248|0.046}} }} {{Orbitbox planet | exoplanet = e | mass_earth = <&nbsp;3.9 | radius_earth = {{val|1.940|0.040}} | semimajor = {{val|0.1785|0.0022}} | period = {{val|30.793091|(12)}} | eccentricity = | inclination = {{val|89.867|0.089}} }} {{Orbitbox planet | exoplanet = f | mass_earth = {{val|5.04|1.89|1.94}} | radius_earth = {{val|2.601|0.042}} | semimajor = {{val|0.2163|0.0026}} | period = {{val|41.05854|(10)}} | eccentricity = | inclination = {{val|89.673|0.046}} }} {{Orbitbox planet | exoplanet = g | mass_earth = <&nbsp;8.4 | radius_earth = {{val|2.607|0.052}} | semimajor = {{val|0.2621|0.0032}} | period = {{val|54.76992|(20)}} | eccentricity = | inclination = {{val|89.729|0.073}} }} {{Orbitbox end}}

{{clear}}

==See also== {{div col|colwidth=30}} * [[HD 10180]] – star with six known planets * [[Kepler-11]] – star with six Neptune-like planets * [[LHS 1140]] – star with a system of planets having an atmosphere * [[List of potentially habitable exoplanets]] * [[LP 890-9]] – second known coolest star with planets * [[Tabby's Star]] – star with notable transit data * [[TRAPPIST-1]] – star with a resonant chain of Earth-sized planets {{div col end}}

==References== {{Reflist|25em|refs=

<ref name=Apps2023>{{cite journal |last1=Apps |first1=Kevin |last2=Luque |first2=Rafael |date=December 2023 |title=HD&nbsp;110067 is a wide hierarchical triple system |journal=[[Research Notes of the AAS]] |volume=7 |issue=12 |pages=12 |doi=10.3847/2515-5172/ad12d0 |doi-access=free |arxiv=2312.04599 }}</ref>

<ref name=GaiaDR3>{{cite Gaia DR3|3948424496764080640}}</ref>

<ref name=Luque2023>{{cite journal |last1=Luque |first1=R. |last2=Osborn |first2=H.P. |display-authors=etal |date=29 November 2023 |title=A resonant sextuplet of sub-Neptunes transiting the bright star HD&nbsp;110067 |journal=[[Nature (journal)|Nature]] |volume=623 |issue=7989 |pages=932–937 |doi=10.1038/s41586-023-06692-3 |arxiv=2311.17775 |bibcode=2023Natur.623..932L }}</ref>

<ref name=SA-20231130EdL>{{cite news |last=de&nbsp;Lazaro |first=Enrico |date=30 November 2023 |title=Astronomers discover resonant system of six sub-neptune exoplanets around HD&nbsp;110067. The bright, nearby star HD&nbsp;110067 hosts six transiting sub-Neptunes that follow a chain of resonant orbits, according to new research led by University of Chicago astronomers. |website=[[Science News]] (sci.news) |url=https://www.sci.news/astronomy/resonant-system-six-sub-neptune-exoplanets-hd-110067-12496.html |url-status=live |access-date=2 December 2023 |archive-url=https://archive.today/20231202140812/https://www.sci.news/astronomy/resonant-system-six-sub-neptune-exoplanets-hd-110067-12496.html |archive-date=2 December 2023 }}</ref>

<ref name=SIMBAD>{{cite simbad |title=HD 110067 |access-date=1 December 2023}}</ref>

<ref name=holmberg2009>{{cite journal |last1=Holmberg |first1=J. |last2=Nordström |first2=B. |last3=Andersen |first3=J. |title=The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics |journal=Astronomy and Astrophysics |date=2009 |volume=501 |issue=3 |page=941 |doi=10.1051/0004-6361/200811191 |arxiv=0811.3982 |bibcode=2009A&A...501..941H }}</ref>

<ref name=yoss1997>{{cite journal |last1=Yoss |first1=K. M. |last2=Griffin |first2=R. F. |title=Radial Velocities and DDO, BV Photometry of Henry Draper G5-M Stars Near the North Galactic Pole |journal=Journal of Astrophysics and Astronomy |date=1997 |volume=18 |issue=2–3 |page=161 |doi=10.1007/BF02714877 |bibcode=1997JApA...18..161Y }}</ref>

<ref name=reiners2020>{{cite journal |last1=Reiners |first1=Ansgar |last2=Zechmeister |first2=Mathias |title=Radial Velocity Photon Limits for the Dwarf Stars of Spectral Classes F-M |journal=The Astrophysical Journal Supplement Series |date=2020 |volume=247 |issue=1 |page=11 |doi=10.3847/1538-4365/ab609f |doi-access=free |arxiv=1912.04120 |bibcode=2020ApJS..247...11R }}</ref>

}}

==Further reading== * {{cite journal |first1=Jacob L. |last1=Bean |first2=Sean N. |last2=Raymond |first3=James E. |last3=Owen |date=22 October 2020 |title=The Nature and Origins of Sub-Neptune Size Planets |journal=Journal of Geophysical Research: Planets |volume=126 |doi=10.1029/2020JE006639 |arxiv=2010.11867 }}

==External links== <!-- {{Commons category}} --> * {{youTube |U8jQEnpQfBM |HD 110067 – Planetary System (video; 2:33)}} {{2023 in space}} {{Stars of Coma Berenices|collapsed=yes}} {{Portal bar|Astronomy|Biology|Outer space|Star}} [[Category:2023 in outer space]] [[Category:Coma Berenices]] [[Category:Durchmusterung objects|BD+20 2748]] [[Category:Henry Draper Catalogue objects|110067]] [[Category:K-type main-sequence stars]] [[Category:Planetary systems with six confirmed planets]] [[Category:TESS Objects of Interest|1835]] [[Category:Triple star systems]]