View source for Astronomy:HD 110067

{{Short description|Star with six sub-Neptune sized planets in the constellation Coma Berenices}}
{{Sky|12|39|21.50369|+|20|01|40.0360|100}}
{{Starbox begin
| name = HD&nbsp;110067
}}
{{Starbox observe
| epoch = J2000
| constell = [[Astronomy:Coma Berenices|Coma Berenices]]
| ra = {{RA|12|39|21.50369}}<ref name=GaiaDR3/>
| dec = {{DEC|+20|01|40.0360}}<ref name=GaiaDR3/>
| appmag_v = 8.43<ref name=SIMBAD/>
}}
{{Starbox character
| type = [[Astronomy:Main sequence|Main sequence]]
| class = K0V<ref name=SIMBAD/>
}}
{{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/>
}}
{{Starbox detail
| source = <ref name=Luque2023/>
| mass = {{val|0.798|0.042}}
| radius = {{val|0.788|0.008}}
| luminosity = 
| 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 [[Astronomy:Sub-Neptune|sub-Neptune]] [[Astronomy:Exoplanet|exoplanet]]s (b, c, d, e, f, g) with radii ranging from 1.94&nbsp;[[Astronomy:Earth radius|{{mvar|R}}{{sub|⊕}}]] to 2.85&nbsp;{{mvar|R}}{{sub|⊕}}. The planets orbit the host star in a rhythmic orbital resonance. The star, and related planetary system, is located 105&nbsp;[[Astronomy:Light-year|light-year]]s away in the constellation [[Astronomy:Coma Berenices|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 |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=[[Organization:NASA|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: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={{wipe|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 [[Astronomy:Spectroscopic binary|spectroscopic binary]] system HD&nbsp;110106.<ref name=Apps2023/>

==Description==
HD&nbsp;110067, located 100&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 1.94&nbsp;{{mvar|R}}{{sub|⊕}} to 2.85&nbsp;{{mvar|R}}{{sub|⊕}}, and with densities (and solid cores) similar to that of [[Astronomy:Gas giant|gas giant]]s in the Solar System. None of the planets in the planetary system were found to be in the [[Astronomy: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 [[Astronomy:K-type main-sequence star|K0-type star]], were first detected by the [[Astronomy:Transiting Exoplanet Survey Satellite|TESS]] ([[Organization:NASA|NASA]]) [[Astronomy:Space telescope|space telescope]], using the [[Astronomy: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 [[Astronomy:CHEOPS|CHEOPS]] ([[Organization:European Space Agency|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 [[Organization:University of Chicago|University of Chicago]], published a review of the discovery in the 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 [[Astronomy:Solar System|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 [[Astronomy:Astronomical object|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 [[Astronomy:Sub-Neptune|sub-Neptune]] [[Astronomy:Exoplanet|exoplanet]]s (b, c, d, e, f, g) with orbital radii ranging from 1.94&nbsp;{{mvar|R}}{{sub|⊕}} to 2.85&nbsp;{{mvar|R}}{{sub|⊕}} from HD&nbsp;110067, the host star. All planets are smaller than Neptune and have large atmospheres. The star and related planetary system are located 100&nbsp;light years away, in the constellation [[Astronomy:Coma Berenices|Coma Berenices]]. Masses of all six of the planets in the system range from 3.9&nbsp;{{mvar|M}}{{sub|⊕}} (mass of Earth) to 8.5&nbsp;{{mvar|M}}{{sub|⊕}}. All of the planetary orbits in the HD&nbsp;110067 system are closer to their star than distance between the planet [[Astronomy:Mercury (planet)|Mercury]] and the [[Astronomy:Sun|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 [[Astronomy: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/> The resonance period is ~492&nbsp;[[Day|{{mvar|d}}{{sub|⊕}}]] (Earth-days).{{cn|date=November 2023}}
{{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}}
* [[Astronomy:HD 10180|HD 10180]] – star with six known planets
* [[Astronomy:Kepler-11|Kepler-11]] – star with six Neptune-like planets
* [[Astronomy:LHS 1140|LHS 1140]] – star with a system of planets having an atmosphere
* [[Astronomy:List of potentially habitable exoplanets|List of potentially habitable exoplanets]]
* [[Astronomy:LP 890-9|LP 890-9]] – second known coolest star with planets
* [[Astronomy:Tabby's Star|Tabby's Star]] – star with notable transit data
* [[Astronomy:TRAPPIST-1|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=[[Astronomy:Research Notes of the AAS|Research Notes of the AAS]] |volume=7 |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=0 |date=29 November 2023 |title=A resonant sextuplet of sub-Neptunes transiting the bright star HD&nbsp;110067 |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>

}}

==Further reading==
* {{cite arxiv |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 |eprint=2010.11867 }}

==External links==
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{{Stars of Coma Berenices|collapsed=yes}}
[[Category:Coma Berenices]]
[[Category:Durchmusterung objects|BD+20 2748]]
[[Category:Henry Draper Catalogue objects|110067]]
[[Category:K-type main-sequence stars]]
[[Category:Triple star systems]]

{{Sourceattribution|HD 110067}}