HD 114762

{{Short description|Triple star system in the constellation Coma Berenices}} {{Starbox begin | name = HD 114762 }} {{Starbox observe | epoch = J2000.0 | constell = [[Coma Berenices]] | ra = {{RA|13|12|19.74107}}<ref name="GaiaDR3"/> | dec = {{DEC|+17|31|01.6303}}<ref name="GaiaDR3"/> | appmag_v = 7.30<ref name="Kane2011"/> + 15.00<ref name="Patience2002"/> }} {{Starbox character | component = A | type = [[subgiant]]<ref name="Kiefer2019"/> | class = F9<ref name="Kiefer2019"/>  | b-v = 0.525<ref name="Kane2011"/>  }} {{Starbox character|no_heading=y | component = B | type = [[Main sequence]]<ref name="Kiefer2019"/> | class = [[Red dwarf|sdM9]]<ref name=bowler2099/> | j-k = 0.70 }} {{Starbox astrometry | radial_v = {{val|49.63|0.18}}<ref name="GaiaDR3"/> | prop_mo_ra = −580.999 | prop_mo_dec = 1.062 | pm_footnote = <ref name="GaiaDR3"/> | parallax = 26.1979 | p_error = 0.1082 | parallax_footnote = <ref name="GaiaDR3"/> }} {{Starbox orbit | reference = <ref name="Winn2022"/> | name = HD 114762 Ab | period_unitless = {{val|83.91712|0.00064|ul=d}} | axis_unitless = {{val|0.361|0.012|ul=AU}}<ref name="Kiefer2020"/> | eccentricity = {{val|0.3442|0.0012}} | inclination = {{val|2.8|0.6}} | node = | periastron = {{val|2449969.202|0.048}} | periarg_primary = {{val|201.3|1.0}}<ref name="Kiefer2020"/> | k1 = {{val|0.6201|0.00085}} }} {{Starbox detail | component1 = HD 114762 A | mass = {{val|1.046|0.040}}<ref name="Winn2022"/> | radius = {{val|1.24|0.05}}<ref name="Kane2011"/> | gravity = {{val|4.18|0.03}}<ref name="Kiefer2019"/> | temperature = {{val|5869|13}}<ref name="Kiefer2019"/> | metal_fe = {{val|-0.72|0.05|0.07}}<ref name="Kiefer2019"/> | rotational_velocity {{val|1.77|0.50}}<ref name="Kane2011"/> | age_gyr = {{val|12|4}}<ref name="Kiefer2019"/> | component2 = HD 114762 Ab | mass2 = {{val|0.293|0.103|0.056}}<ref name="Winn2022"/> }} {{Starbox detail|no_heading=y | component1 = HD 114762 B | mass = 0.0879<ref name=bowler2099/> | temperature = 2,645<ref name=bowler2099/> | luminosity = 0.00043<ref name=bowler2099/> | radius = 0.100<ref name=bowler2099/> | gravity = 5.381<ref name=bowler2099/> | metal_fe = −0.71<ref name=bowler2099/> | age_gyr = ~10<ref name=bowler2099/> }} {{Starbox catalog | names = {{odlist | HD=114762 | 2MASS=J13121982+1731016 | BD=+18 2700 | HIP=64426 | SAO=100458 }}<ref name="Simbad"/> }} {{Starbox reference | Simbad = HD+114762 | NSTED = HD 114762 | ARICNS = 04169 | EPE = HD+114762 }} {{Starbox end}}

'''HD 114762''' is a [[triple star]] system<ref name="Patience2002"/><ref name="Kiefer2019"/> approximately {{convert|38.2|pc|disp=flip|lk=on}} away in the [[constellation]] [[Coma Berenices]]. It consists of a yellow-white [[F-type main-sequence star]] {{nowrap|(HD 114762 A)}} and two [[red dwarf]] companions {{nowrap|(HD 114762 Ab}} & {{nowrap|HD 114762 B)}} approximately 0.36 & {{nowrap|130 [[astronomical unit|AU]]}} distant.<ref name="Patience2002" /><ref name="Kiefer2019"/> Both are low-metal [[subdwarf]]s. Planets around such metal-poor stars are rare (three known cases are [[HD 22781]], [[HD 111232]], and [[HD 181720]]).<ref>{{citation|arxiv=1902.04493|year=2019|doi=10.3390/geosciences9030105|last1=Adibekyan|first1=Vardan|title=Heavy Metal Rules. I. Exoplanet Incidence and Metallicity|journal=Geosciences|volume=9|issue=3|page=105|bibcode=2019Geosc...9..105A|s2cid=119089419|doi-access=free}}</ref> A [[telescope]] or strong [[binoculars]] are needed to view the primary. {{nowrap|HD 114762}} had been used by scientists as a "standard star", one whose [[radial velocity]] is well established, but with the discovery of the spectroscopic companion {{nowrap|[[HD 114762 b|HD 114762 Ab]]}} its usefulness as a standard has been called into question.<ref name="latimes19880804"/>

The smaller red dwarf companion (HD 114762 B) is classified as an [[ultra-cool dwarf]], with a spectral type around M9.<ref name=bowler2099/> With a [[Apparent magnitude|visual magnitude]] of 15 and separated from the primary by only three [[arcsecond]]s, it can only be seen with a powerful telescope.<ref name="Patience2002"/> It is estimated to be around 10 billion years old, although the properties of such low-mass stars are very similar across a wide range of ages. It is calculated have only 8% of the [[mass of the Sun]], a tenth of [[solar radius|its radius]], and with a temperature of about {{val|fmt=commas|2645|ul=K}} it produces less than a thousandth of [[solar luminosity|its luminosity]].<ref name=bowler2099/>

==Spectroscopic companion== {{Main|HD 114762 b}} In 1989, a companion object, {{nowrap|HD 114762 Ab}}, was found orbiting {{nowrap|HD 114762 A}} by Latham, ''et al''., using [[Doppler spectroscopy]],<ref name="Latham1989"/> but its existence was not confirmed until 1991 by Cochran, ''et al''.<ref name="Cochran1991"/> Its orbital distance and revolution is similar to that of [[Mercury (planet)|Mercury]], though it has twice the [[orbital eccentricity|eccentricity]].<ref name="Cochran1991"/> It has a [[minimum mass]] of {{Jupiter mass|10.69|link=yes}}, and thus was originally thought to be a massive [[exoplanet]]; however, in 2019, its [[orbital inclination|inclination]] was determined by [[Gaia (spacecraft)|Gaia]] [[astrometry]], giving it a true mass of {{Jupiter mass|141|link=yes}}. This makes it a [[red dwarf]] star, or a massive [[brown dwarf]].<ref name="Kiefer2019"/> A 2020 study provided further confirmation of this, and revised the mass upwards to {{Jupiter mass|147}},<ref name="Kiefer2020"/> and in 2022 this mass was revised upwards still further, to {{Solar mass|0.293|link=y}}, based on [[Gaia DR3]] data and a similar upwards revision to the mass of the primary star.<ref name="Winn2022"/>

==References== {{Reflist|refs=

<ref name="Cochran1991">{{cite journal |title=Constraints on the Companion Object to HD 114762 |journal=[[The Astrophysical Journal]] |first1=William D. |last1=Cochran |first2=Artie P. |last2=Hatzes |first3=Terry J. |last3=Hancock |volume=380 |pages=L35–L38 |date=10 October 1991 |doi=10.1086/186167 |bibcode=1991ApJ...380L..35C|doi-access=free }}</ref>

<ref name=bowler2099>{{cite journal| bibcode=2009ApJ...706.1114B | title=The Benchmark Ultracool Subdwarf HD 114762B: A Test of Low-metallicity Atmospheric and Evolutionary Models | last1=Bowler | first1=Brendan P. | last2=Liu | first2=Michael C. | last3=Cushing | first3=Michael C. | journal=The Astrophysical Journal | year=2009 | volume=706 | issue=2 | page=1114 | doi=10.1088/0004-637X/706/2/1114 | arxiv=0910.1604 | s2cid=119112746 }}</ref>

<ref name="Kane2011">{{cite journal |title=Revised Orbit and Transit Exclusion for HD 114762b |journal=The Astrophysical Journal Letters |last1=Kane |first1=Stephen R. |last2=Henry |first2=Gregory W. |last3=Dragomir |first3=Diana |last4=Fischer |first4=Debra A. |last5=Howard |first5=Andrew W. |last6=Wang |first6=Xuesong |last7=Wright |first7=Jason T. |display-authors=1 |volume=735 |issue=2 |at=L41 |year=2011 |arxiv=1106.1434 |bibcode=2011ApJ...735L..41K |doi=10.1088/2041-8205/735/2/L41|s2cid=118409104 }}</ref>  <ref name="latimes19880804">{{cite news |url=https://www.latimes.com/archives/la-xpm-1988-08-04-mn-10212-story.html |title=Other Planets, Other Suns: Astronomers Say Star's Wobble Tells a Story |work=[[Los Angeles Times]] |first=Thomas H. |last=Maugh II |date=4 August 1988 |access-date=7 September 2014}}</ref>

<ref name="Latham1989">{{cite journal |title=The unseen companion of HD114762 - A probable brown dwarf |journal=[[Nature (journal)|Nature]] |first1=David W. |last1=Latham |first2=Tsevi |last2=Mazeh |first3=Robert P. |last3=Stefanik |first4=Michel |last4=Mayor |first5=Gilbert |last5=Burki |volume=339 |issue=6219 |pages=38–40 |date=May 1989 |doi=10.1038/339038a0 |bibcode=1989Natur.339...38L|s2cid=4324036 }}</ref>

<ref name="Patience2002">{{cite journal |title=Stellar Companions to Stars with Planets |journal=[[The Astrophysical Journal]] |first1=J. |last1=Patience |first2=R. J. |last2=White |first3=A. M. |last3=Ghez |first4=C. |last4=McCabe |first5=I. S. |last5=McLean |first6=J. E. |last6=Larkin |first7=L. |last7=Prato |first8=Sungsoo S. |last8=Kim |first9=J. P. |last9=Lloyd |first10=M. C. |last10=Liu |first11=J. R. |last11=Graham |first12=B. A. |last12=Macintosh |first13=D. T. |last13=Gavel |first14=C. E. |last14=Max |first15=B. J. |last15=Bauman |first16=S. S. |last16=Olivier |first17=P. |last17=Wizinowich |first18=D. S. |last18=Acton |display-authors=5 |volume=581 |issue=1 |pages=654–665 |date=December 2002 |doi=10.1086/342982 |bibcode=2002ApJ...581..654P |arxiv=astro-ph/0207538|s2cid=119519887 }}</ref>

<ref name="Simbad">{{cite simbad | title=HD 114762 | access-date=2019-01-16 }}</ref>  <ref name="Kiefer2019">{{cite journal |title=Determining the mass of the planetary candidate HD 114762 b using Gaia |arxiv=1910.07835 |last1=Kiefer |first1=Flavien |journal=Astronomy & Astrophysics |date=17 October 2019|volume=632 |pages=L9 |doi=10.1051/0004-6361/201936942 |bibcode=2019A&A...632L...9K |s2cid=204743831 }}</ref>

<ref name="Kiefer2020">{{cite journal | title=Determining the true mass of radial-velocity exoplanets with Gaia. Nine planet candidates in the brown dwarf or stellar regime and 27 confirmed planets | last1=Kiefer | first1=F. | last2=Hébrard | first2=G. | last3=Lecavelier des Etangs | first3=A. | last4=Martioli | first4=E. | last5=Dalal | first5=S. | last6=Vidal-Madjar | first6=A. | display-authors=1 | journal=Astronomy & Astrophysics | volume=645 | page= | article-number=A7 | date=January 2021 | arxiv=2009.14164 | bibcode=2021A&A...645A...7K | bibcode-access=free | doi=10.1051/0004-6361/202039168 | doi-access=free | s2cid=221995447 }}</ref>

<ref name="Winn2022">{{cite journal |last=Winn |first=Joshua N. |arxiv=2209.05516 |title=Joint Constraints on Exoplanetary Orbits from Gaia DR3 and Doppler Data |journal=The Astronomical Journal |date=September 2022|volume=164 |issue=5 |page=196 |doi=10.3847/1538-3881/ac9126 |bibcode=2022AJ....164..196W |s2cid=252211643 |doi-access=free }}</ref>

}}

[[Category:Coma Berenices]] [[Category:Triple star systems]] [[Category:F-type main-sequence stars]] [[Category:M-type main-sequence stars]] [[Category:Henry Draper Catalogue objects|114762]] [[Category:Durchmusterung objects|BD+18 2700]] [[Category:Hipparcos objects|064426]] [[Category:Am stars]]