View source for HD 85512

{{Short description|Star in the constellation Vela}}
{{Starbox begin}}
{{Starbox image
| image = [[File:HD 85512.jpg|250px]]
| caption = HD 85512 imaged by the [[Digitized Sky Survey]]
}}
{{Starbox observe 
| epoch = J2000 
| constell = [[Vela (constellation)|Vela]] 
| ra = {{RA|09|51|07.05180}}<ref name="Gaia DR3"/>
| dec = {{DEC|−43|30|10.0237}}<ref name="Gaia DR3"/>
| appmag_v = 7.66  
}}
{{Starbox character 
| class = K6V<ref name=Escude2012/>
| r-I = 0.62 
| v-r = 0.71 
| b-v = 1.18 
| u-b = 1.12 
| variable =
}}
{{Starbox astrometry 
| radial_v = {{val|−9.78|0.12}}<ref name="Gaia DR3"/>
| prop_mo_ra = 461.603
| prop_mo_dec = −471.880
| pm_footnote = <ref name="Gaia DR3"/>
| parallax = 88.6737
| p_error = 0.0173
| parallax_footnote = <ref name="Gaia DR3"/>
| absmag_v = 7.39<ref name=Holmberg2009/>
}}
{{Starbox detail
|source=<ref name=Escude2012>{{citation|arxiv=1202.2570|title=The HARPS-TERRA project. I. Description of the algorithms, performance, and new measurements on a few remarkable stars observed by HARPS|year=2012|doi=10.1088/0067-0049/200/2/15|last1=Anglada-Escudé|first1=Guillem|last2=Butler|first2=R. Paul|journal=The Astrophysical Journal Supplement Series|volume=200|issue=2|page=15|bibcode=2012ApJS..200...15A |s2cid=118528839}}</ref><ref name=Soto2018>[http://cdsarc.u-strasbg.fr/viz-bin/nph-Cat/html?J/A+A/615/A76/tablea3.dat Spectroscopic Parameters and atmosphEric ChemIstriEs of Stars (SPECIES) I. Code description and dwarf stars catalogue Full table D.1]</ref>
| mass = 0.69
| radius = {{nowrap|0.533 ± 0.04}}<ref group="note">From <math>R = \sqrt \frac{L} {4 \pi \sigma T_{\rm eff} ^4}</math>, where <math>R</math> is the radius, <math>L</math> is the luminosity, <math>T_{\rm eff}</math> is the effective surface temperature and <math>\sigma</math> is the [[Stefan–Boltzmann constant]].</ref>
| luminosity_bolometric = {{nowrap|0.126 ± 0.008}}
| temperature = 4404{{±|10}}
| metal_fe = -0.28
| metal = ([Si/H] dex) -0.02
| gravity = 4.604{{±|0.017}}
| rotation = 47.13 ± 6.98
| rotational_velocity = 2.194{{±|0.118}}
| age_gyr = 5.61 ± 0.61 
}}
{{Starbox catalog 
| names = {{odlist | 2MASS=J09510700-4330097 | CD=−42°5678 | GJ=370 | HD=85512 | HIP=48331 | LHS=2201|Gaia DR2=5412947081287925504}}<ref name="Simbad"/>
}}
{{Starbox reference
| Simbad = HD+85512
}}
{{Starbox end}}

'''HD 85512''' is a solitary [[K-type main-sequence star]] {{convert|36.8|ly|pc|lk=on|abbr=off}} away in the constellation [[Vela (constellation)|Vela]]. It is about 1 billion years older than the [[Sun]]. It is extremely [[chromosphere|chromospherically]] inactive, only slightly more active than [[Tau Ceti]]. It exhibits a long-term variability<ref name=Escude2012/> and was thought to host one low-mass planet, although this is now doubtful.<ref name="Laliotis2023"/>

==Proposed planetary system==
On August 19, 2011, a ≥3.6 [[Earth mass|Earth-mass]] planet was discovered using [[HARPS]] that is "just inside" the [[habitable zone]], along with the [[82 G. Eridani#Planetary system|inner planets of e (or 82 G.) Eridani]], and [[HD 192310 c]] in Capricornus. These two other systems are closer to Earth than this system.<ref name="Pepe2011"/> Modelling at the time of the discovery announcement found that the planet could be cool enough to host liquid water if it has more than 50% cloud coverage,<ref name="Kaltenegger2011"/> but with revised models of the habitable zone two years later it was found to be too hot to be potentially habitable.<ref name="Kopparapu2013"/> For a time it ranked fifth-best for habitability in the [[Planetary Habitability Laboratory]]'s Habitable Exoplanets Catalog, which later listed it in an article about "false starts" in the search for potentially habitable exoplanets.<ref>{{Cite web|url=http://phl.upr.edu/library/notes/falsestarts|title=False Starts: Potentially Habitable Exoplanets - Planetary Habitability Laboratory @ UPR Arecibo|access-date=2020-11-15|archive-date=2021-10-18|archive-url=https://web.archive.org/web/20211018065612/http://phl.upr.edu/library/notes/falsestarts|url-status=dead}}</ref>

In 2023, a study reassessed the [[radial velocity]] data of HD 85512. A signal was detected with a period of 51 days, inconsistent with the previously published 58-day orbital period of HD 85512 b, but consistent with previous estimates of the stellar rotation period. This indicates that the signal is very likely to be caused by the stellar rotation, rather than an orbiting planet.<ref name="Laliotis2023"/>{{rp|25-27}}<ref name="Laliotis2023"/>{{rp|44}} Due to this, the [[NASA Exoplanet Archive]] now considers this planet as a false positive detection.<ref>{{cite exoplanet archive|HD 85512|access-date=August 12, 2024}}</ref>

==References==
{{reflist|refs=

<ref name="Gaia DR3">{{Cite Gaia DR3|5412947081295024896}}</ref>

<ref name=Holmberg2009>{{citation
 | display-authors=1 | 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
 | volume=501 | issue=3 |date=July 2009 | pages=941–947
 | journal=Astronomy and Astrophysics
 | doi=10.1051/0004-6361/200811191 | bibcode=2009A&A...501..941H
 | arxiv=0811.3982 | s2cid=118577511 | postscript=. }}</ref>

<ref name="Pepe2011">{{cite journal | title=The HARPS search for Earth-like planets in the habitable zone. I. Very low-mass planets around HD 20794, HD 85512, and HD 192310 | url=http://www.aanda.org/articles/aa/full_html/2011/10/aa17055-11/aa17055-11.html | last1=Pepe | first1=F. | last2=Lovis | first2=C. | last3=Ségransan | first3=D. | last4=Benz | first4=W. | last5=Bouchy | first5=F. | last6=Dumusque | first6=X. | last7=Mayor | first7=M. | last8=Queloz | first8=D. | last9=Santos | first9=N. C. | last10=Udry | first10=S. | display-authors=1 | journal=Astronomy and Astrophysics | volume=534 | at=A58 | year=2011 | arxiv=1108.3447 | bibcode=2011A&A...534A..58P | bibcode-access=free | doi=10.1051/0004-6361/201117055 | doi-access=free }}</ref>

<ref name="Simbad">{{cite simbad | title=HD 85512 | access-date=2019-09-22 }}</ref>

<ref name="Kaltenegger2011">{{cite arXiv |title=A Habitable Planet around HD 85512? |first1=L. |last1=Kaltenegger |first2=S. |last2=Udry |first3=F. |last3=Pepe |date=2011|class=astro-ph.EP |eprint=1108.3561}}</ref>

<ref name="Kopparapu2013">{{cite journal |title=Habitable Zones Around Main-Sequence Stars: New Estimates |first1=Ravi Kumar |last1=Kopparapu |first2=Ramses |last2=Ramirez |first3=James F. |last3=Kasting |first4=Vincent |last4=Eymet |first5=Tyler D. | last5=Robinson |first6=Suvrath | last6=Mahadevan |first7=Ryan C. | last7=Terrien |first8=Shawn | last8=Domagal-Goldman |first9=Victoria | last9=Meadows |first10=Rohit | last10=Deshpande |display-authors=1 |date=2013|arxiv=1301.6674 |bibcode=2013ApJ...765..131K|doi = 10.1088/0004-637X/765/2/131 | volume=765 |issue=2 | journal=The Astrophysical Journal | pages=131|s2cid=76651902 }}</ref>

<ref name="Laliotis2023">{{cite journal|last1=Laliotis|first1=Katherine|last2=Burt|first2=Jennifer A.|last3=Mamajek|first3=Eric E.|last4=Li|first4=Zhexing|last5=Perdelwitz|first5=Volker|last6=Zhao|first6=Jinglin|last7=Butler|first7=R. Paul|last8=Holden|first8=Bradford|last9=Rosenthal|first9=Lee|last10=Fulton|first10=B. J.|last11=Feng|first11=Fabo|last12=Kane|first12=Stephen R.|last13=Bailey|first13=Jeremy|last14=Carter|first14=Brad|last15=Crane|first15=Jeffrey D.|last16=Furlan|first16=Elise|last17=Gnilka|first17=Crystal L.|last18=Howell|first18=Steve B.|last19=Laughlin|first19=Gregory|last20=Shectman|first20=Stephen A.|last21=Teske|first21=Johanna K.|last22=Tinney|first22=C. G.|last23=Vogt|first23=Steven S.|last24=Wang|first24=Sharon Xuesong|last25=Wittenmyer|first25=Robert A.|display-authors=3|title=Doppler Constraints on Planetary Companions to Nearby Sun-like Stars: An Archival Radial Velocity Survey of Southern Targets for Proposed NASA Direct Imaging Missions|journal=The Astronomical Journal |arxiv=2302.10310|date=22 February 2023|volume=165 |issue=4 |page=176 |doi=10.3847/1538-3881/acc067 |doi-access=free |bibcode=2023AJ....165..176L }}</ref>

}}

==Notes==
{{Reflist|group=note}}

==External links==
* {{ARICNS link|id=4c00766|label='''ARICNS''': 00766}}

{{Sky|09|51|07.1|-|43|30|10|36.3}}

{{Stars of Vela}}

{{DEFAULTSORT:HD 85512}}
[[Category:HD 85512| ]]
[[Category:Vela (constellation)]]
[[Category:Henry Draper Catalogue objects|085512]]
[[Category:Hipparcos objects|048331]]
[[Category:Gliese and GJ objects|0370]]
[[Category:K-type main-sequence stars]]
[[Category:Hypothetical planetary systems]]
[[Category:Durchmusterung objects]]
[[Category:2MASS objects|J09510700-4330097]]