View source for HD 219134

{{short description|Star in the constellation Cassiopeia}}
{{Starbox begin
| name = HD 219134
}}
{{Starbox image
| image = [[File:PIA19832-StarHD219134-Location-20150730.jpg|300px]]
| caption = Star HD 219134 (circled) lies just off the "W" shape of the constellation Cassiopeia.
}}
{{Starbox observe
| epoch = J2000
| constell = [[Cassiopeia (constellation)|Cassiopeia]]
| ra = {{RA|23|13|16.97496}}<ref name="GaiaDR3"/>
| dec = {{DEC|+57|10|06.0838}}<ref name="GaiaDR3"/>
| appmag_v = 5.574<ref name=aaass65_2_405/>
}}
{{Starbox character
| class = K3V<ref name=aaa508_3_1313/>
| b-v = +0.983<ref name=aaass65_2_405/>
| u-b = +0.902<ref name=aaass65_2_405/>
| variable = Suspected<ref name=csvs/>
}}
{{Starbox astrometry
| radial_v = {{val|-18.68|0.12}}<ref name="GaiaDR3"/>
| prop_mo_ra = {{val|2074.414}}
| prop_mo_dec = {{val|294.452}}
| pm_footnote = <ref name="GaiaDR3"/>
| parallax = 152.8640
| p_error = 0.0494
| parallax_footnote = <ref name="GaiaDR3"/>
| absmag_v = 6.46<ref name=Holmberg2009/>
}}
{{Starbox detail
| age_gyr = {{nowrap|11.0}}<ref name=NASAExoplanetArchive>{{cite web
 | url=https://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?objname=HD+219134&type=PLANET_HOST
 | title=HD 219134
 | work=exoplanetarchive.ipac.caltech.edu
 | access-date=2017-12-24
}}</ref>
| metal_fe = +0.11 (± 0.04)<ref name=NASAExoplanetArchive/>
| mass = {{val|0.81|0.03}}<ref name=NASAExoplanetArchive/>
| gravity = {{val|4.567|0.018}}<ref name=NASAExoplanetArchive/>
| radius = {{val|0.7784|0.0053}}<ref name=Boyajian/>
| rotational_velocity = 6.94<ref name=aaa520_A79/>
| luminosity ={{val|0.265|0.002}}<ref name=Boyajian/>
| temperature = {{val|4699|16|fmt=commas}}<ref name=Boyajian/>
| habitable_inner = 0.467<ref name=Boyajian/> [[Astronomical unit|AU]]
| habitable_outer = 0.926<ref name=Boyajian/> AU
}}
{{Starbox catalog
| names = [[Durchmusterung|BD]]+56&nbsp;2966, [[FK5]]&nbsp;875, [[General Catalogue of Trigonometric Parallaxes|GCTP]]&nbsp;5616.00, [[Gliese Catalogue of Nearby Stars|Gl]]&nbsp;892, [[Henry Draper catalogue|HD]]&nbsp;219134, [[Hipparcos catalogue|HIP]]&nbsp;114622, [[Bright Star Catalogue|HR]] 8832, [[Luyten Five-Tenths catalogue|LFT]]&nbsp;1767, [[Luyten Half-Second catalogue|LHS]]&nbsp;71, [[Luyten Two-Tenths catalogue|LTT]]&nbsp;16826, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]]&nbsp;35236.<ref name=SIMBAD/>
}}
{{Starbox reference
| Simbad = HR+8832
}}
{{Starbox end}}

'''HD 219134''' (also known as '''Gliese 892''' or '''HR 8832''') is a [[main sequence|main-sequence]] star in the [[constellation]] of [[Cassiopeia (constellation)|Cassiopeia]]. It is smaller and less luminous than the [[Sun]], with a [[spectral class]] of K3V, which makes it an orange-hued star. HD 219134 is relatively close to our system, with an estimated distance of 21.34 [[light year]]s. This star is close to the limit of [[apparent magnitude]] that can still be seen by the unaided eye. The limit is considered to be magnitude 6 for most observers. This star has a magnitude 9.4 optical companion at an angular separation of 106.6&nbsp;[[arcsecond]]s.<ref name=mnras389_2_869/>

== Planetary system ==
HD 219134 has a system of six known [[exoplanet]]s. The innermost planet, [[HD 219134 b]], is a rocky [[super-Earth]] based on size (1.6 Earth radii), and density (6.4 grams per cubic cm).<ref name="NASA-20150730">{{cite web |title=PIA19832: Location of Nearest Rocky Exoplanet Known |url=http://photojournal.jpl.nasa.gov/catalog/PIA19832 |date=30 July 2015 |work=[[NASA]] |access-date=30 July 2015 }}</ref><ref name="NASA-20150730-fc">{{cite web |last1=Chou |first1=Felicia |last2=Clavin |first2=Whitney |title=NASA's Spitzer Confirms Closest Rocky Exoplanet |url=http://www.jpl.nasa.gov/news/news.php?feature=4672 |date=30 July 2015 |work=[[NASA]] |access-date=31 July 2015 }}</ref> This and three additional exoplanets; one [[super-Earth]] (designated ''c'' and later found to be rocky as well), one [[Ice giant|Neptunian]] world (''d''), and one [[Jovian planet|Jovian]] world (''e''); were deduced using HARPS-N radial velocity data by Motalebi ''et al.'' in 2015.<ref name="Motalebi2015" /><ref name="Harvard-Smithsonian-Release No.2015-1">{{cite web |title= Cassiopeia's Hidden Gem |url=https://www.cfa.harvard.edu/news/2015-16|date=30 July 2015 |work=[[Harvard]] |access-date=30 July 2015 }}</ref> Two months later, Vogt ''et al.'' published a paper on this system which found a 6-planet solution, with planets ''b'', ''c'' & ''d'' corresponding to those in Motalebi ''et al.'', ''f'' & ''g'' being new planets, and ''h'' corresponding to Motalebi's ''e'' but with different, and more accurate, estimated parameters.<ref name="Vogt2015" /><ref name="Johnson2016" />

A number of independent studies have been done regarding the planetary system of HD 219134, with some of their results conflicting with each other. As of March 2017, the star is known to have at least 5 planets, with two of them (HD 219134 b and c) known to be transiting, rocky super-Earths.<ref name="Gillon2017" /><ref>{{Cite web|url=http://backalleyastronomy.blogspot.com/2017/04/hd-219134-scorecard-5-planets-2.html?m=1|title=Back Alley Astronomy: HD 219134 Scorecard: 5 planets, 2 transiting|date=18 April 2017}}</ref> While a 2016 study suggested that the radial velocity signal corresponding to planet ''f'' might be caused by stellar activity,<ref name="Johnson2016" /> it has been confirmed by subsequent studies in 2017<ref name="Gillon2017" /> and 2021.<ref name="Rosenthal2021"/> Planet ''g'' has not been reported by subsequent studies, and a 2020 study did not find evidence of its claimed 94-day period, but instead found a period of 192 days.<ref name="Hirsch2020"/>

{{OrbitboxPlanet begin
| name = HD 219134
| table_ref = <ref name="Vogt2015" /><ref name="Johnson2016" /><ref name="Gillon2017" />
}}
{{OrbitboxPlanet
| exoplanet = [[HD 219134 b|b]]
| mass_earth = {{val|4.74|0.19}}
| period = {{val|3.092926|0.000010}}
| semimajor = {{val|0.03876|0.00047}}
| eccentricity = 0 (fixed)
| radius_earth = {{val|1.602|0.055}}
| inclination = {{val|85.05|0.09}}
}}
{{OrbitboxPlanet
| exoplanet = [[HD 219134 c|c]]
| mass_earth = {{val|4.36|0.22}}
| period = {{val|6.76458|0.00033}}
| semimajor = {{val|0.06530|0.00080}}
| eccentricity = {{val|0.062|0.039}}
| radius_earth = {{val|1.511|0.047}}
| inclination = {{val|87.28|0.10}}
}}
{{OrbitboxPlanet
| exoplanet = [[HD 219134 f|f]]
| mass_earth = >{{val|7.30|0.40}}
| period = {{val|22.717|0.015}}
| semimajor = {{val|0.1463|0.0018}}
| eccentricity = {{val|0.148|0.047}}
}}
{{OrbitboxPlanet
| exoplanet = [[HD 219134 d|d]]
| mass_earth = >{{val|16.17|0.64}}
| period = {{val|46.859|0.028}}
| semimajor = {{val|0.2370|0.0030}}
| eccentricity = {{val|0.138|0.025}}
}}
{{OrbitboxPlanet
| exoplanet = [[HD 219134 g|g]]
| mass_earth = >{{val|11|1}}
| period = {{val|94.2|0.2}}
| semimajor = {{val|0.3753|0.0004}}
| eccentricity = 0
}}
{{OrbitboxPlanet
| exoplanet = [[HD 219134 h|h]] (e)<ref>{{citation|arxiv=2209.06958|year=2023|title=TESS-Keck Survey. XIV. Two Giant Exoplanets from the Distant Giants Survey|doi=10.3847/1538-3881/aca6ef |last1=Van Zandt |first1=Judah |last2=Petigura |first2=Erik A. |last3=MacDougall |first3=Mason |last4=Gilbert |first4=Gregory J. |last5=Lubin |first5=Jack |last6=Barclay |first6=Thomas |last7=Batalha |first7=Natalie M. |last8=Crossfield |first8=Ian J. M. |last9=Dressing |first9=Courtney |last10=Fulton |first10=Benjamin |last11=Howard |first11=Andrew W. |last12=Huber |first12=Daniel |last13=Isaacson |first13=Howard |last14=Kane |first14=Stephen R. |last15=Robertson |first15=Paul |last16=Roy |first16=Arpita |last17=Weiss |first17=Lauren M. |last18=Behmard |first18=Aida |last19=Beard |first19=Corey |last20=Chontos |first20=Ashley |last21=Dai |first21=Fei |last22=Dalba |first22=Paul A. |last23=Fetherolf |first23=Tara |last24=Giacalone |first24=Steven |last25=Henze |first25=Christopher E. |last26=Hill |first26=Michelle L. |last27=Hirsch |first27=Lea A. |last28=Holcomb |first28=Rae |last29=Howell |first29=Steve B. |last30=Jenkins |first30=Jon M. |journal=The Astronomical Journal |volume=165 |issue=2 |page=60 |bibcode=2023AJ....165...60V |s2cid=252280288 |display-authors=1 |doi-access=free }}</ref>
| mass_earth = >98
| period = {{val|2100.6|2.9}}
| semimajor = {{val|3.11|0.04}}
| eccentricity = {{val|0.06|0.04}}
}}
{{Orbitbox end}}

=== Habitable Zone ===
The [[Circumstellar habitable zone|conservative habitable zone]] (CHZ) of HD 219134 is estimated to extend from 0.516 to 0.948 AU.<ref name="exoplanetkyoto">{{Cite web|url=http://www.exoplanetkyoto.org/exohtml/HD_219134_g.html|title=HD 219134 g|publisher=[[ExoKyoto]]}}</ref><ref>{{cite web |url=http://hzgallery.org/1356_2.png |title=HD 219134 |website=hzgallery.org}}</ref> None of the planets orbiting the star are confirmed to orbit inside the habitable zone.<ref name="Dietrich2021">{{cite journal |author-link= |arxiv=2112.05337 |title= An Integrative Analysis of the HD 219134 Planetary System and the Inner solar system: Extending DYNAMITE with Enhanced Orbital Dynamical Stability Criteria|last1= Dietrich|first1= Jeremy|last2= Apai|first2= Dániel|last3= Malhotra|first3= Renu|journal=The Astronomical Journal |year= 2022|volume=163 |issue=2 |page=88 |doi=10.3847/1538-3881/ac4166 |bibcode=2022AJ....163...88D |s2cid=245117944 |doi-access=free }}</ref> The planet candidate [[HD 219134 g]] may orbit slightly interior to the inner edge of the habitable zone based on its initially published parameters,<ref name="Vogt2015" /> or may orbit within the habitable zone based on a more recent estimated orbital period of 192 days and semi-major axis of 0.603 AU.<ref name="Hirsch2020"/> This planet is significantly more massive than Earth and therefore it likely retains a dense atmosphere, comparable to the Solar System's [[ice giant]]s.

==References==
{{Reflist|refs=

<ref name=Boyajian>{{Cite journal |last=Boyajian |first=Tabetha S. |last2=von Braun |first2=Kaspar |last3=van Belle |first3=Gerard |last4=McAlister |first4=Harold A. |last5=Brummelaar |first5=Theo A. ten |last6=Kane |first6=Stephen R. |last7=Muirhead |first7=Phil |last8=Jones |first8=Jeremy |last9=White |first9=Russel |last10=Schaefer |first10=Gail |last11=Ciardi |first11=David |last12=Henry |first12=Todd |last13=López-Morales |first13=Mercedes |last14=Ridgway |first14=Stephen |last15=Gies |first15=Douglas |date=2012-10-01 |title=Stellar Diameters and Temperatures II. Main Sequence K & M Stars |arxiv=1208.2431 |journal=The Astrophysical Journal |volume=757 |issue=2 |pages=112 |doi=10.1088/0004-637X/757/2/112 |issn=0004-637X}}</ref>

<ref name="GaiaDR3">{{Cite Gaia DR3|2009481748875806976}}</ref>

<ref name=Holmberg2009>{{citation
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<ref name=aaa508_3_1313>{{citation | display-authors=1 | last1=Frasca | first1=A. | last2=Covino | first2=E. | last3=Spezzi | first3=L. | last4=Alcalá | first4=J. M. | last5=Marilli | first5=E. | last6=Fżrész | first6=G. | last7=Gandolfi | first7=D. | title=REM near-IR and optical photometric monitoring of pre-main sequence stars in Orion. Rotation periods and starspot parameters | journal=Astronomy and Astrophysics | volume=508 | issue=3 | pages=1313–1330 |date=December 2009 | doi=10.1051/0004-6361/200913327 | bibcode=2009A&A...508.1313F | postscript=. | arxiv=0911.0760 | s2cid=118361131 }}</ref>

<ref name=aaa520_A79>{{citation | display-authors=1 | last1=Martínez-Arnáiz | first1=R. | last2=Maldonado | first2=J. | last3=Montes | first3=D. | last4=Eiroa | first4=C. | last5=Montesinos | first5=B. | title=Chromospheric activity and rotation of FGK stars in the solar vicinity. An estimation of the radial velocity jitter | journal=Astronomy and Astrophysics | volume=520 | page=A79 | date=September 2010 | doi=10.1051/0004-6361/200913725 | bibcode=2010A&A...520A..79M | postscript=. | arxiv=1002.4391 | s2cid=43455849 | url=http://eprints.ucm.es/37826/1/davidmontes17libre.pdf | access-date=2018-11-04 | archive-date=2017-09-22 | archive-url=https://web.archive.org/web/20170922031257/http://eprints.ucm.es/37826/1/davidmontes17libre.pdf | url-status=dead }}</ref>

<ref name=aaass65_2_405>{{citation | last1=Oja | first1=T. | title=UBV photometry of stars whose positions are accurately known. III | journal=Astronomy and Astrophysics Supplement Series | volume=65 | issue=2 | pages=405–409 |date=August 1986 | bibcode=1986A&AS...65..405O | postscript=. }}</ref>

<ref name=csvs>{{citation | display-authors=1 | last1=Kukarkin | first1=B. V. | last2=Kholopov | first2=P. N. | last3=Artiukhina | first3=N. M. | last4=Fedorovich | first4=V. P. | last5=Frolov | first5=M. S. | last6=Goranskij | first6=V. P. | last7=Gorynya | first7=N. A. | last8=Karitskaya | first8=E. A. | last9=Kireeva | first9=N. N. | last10=Kukarkina | first10=N. P. | last11=Kurochkin | first11=N. E. | last12=Medvedeva | first12=G. I. | last13=Perova | first13=N. B. | last14=Ponomareva | first14=G. A. | last15=Samus | first15=N. N. | last16=Shugarov | first16=S. Y. | title=Nachrichtenblatt der Vereinigung der Sternfreunde e.V. (Catalogue of suspected variable stars) | journal=Nachrichtenblatt der Vereinigung der Sternfreunde E.V. (1981) | pages=0 | location=Moscow | publisher=Academy of Sciences USSR Shternberg | year=1981 | bibcode=1981CSV...C......0K | postscript=. }}</ref>

<ref name=mnras389_2_869>{{citation | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | title=A catalogue of multiplicity among bright stellar systems | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=389 | issue=2 | pages=869–879 |date=September 2008 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | bibcode=2008MNRAS.389..869E | postscript=. |arxiv = 0806.2878 | s2cid=14878976 }}</ref>

<ref name="Motalebi2015">{{cite journal |arxiv=1507.08532 |last1=Motalebi |first1=F. |display-authors=etal |title=The HARPS-N Rocky Planet Search. I. HD 219134 b: A transiting rocky planet in a multi-planet system at 6.5 pc from the Sun |date=December 2015 |doi=10.1051/0004-6361/201526822 |volume=584 |journal=[[Astronomy & Astrophysics]] |page=A72 |bibcode=2015A&A...584A..72M |s2cid=45652878 }}</ref>

<ref name="Vogt2015">{{cite journal |arxiv=1509.07912 |last1=Vogt |first1=Steven S. |display-authors=etal |title=Six Planets Orbiting HD 219134 |date=November 2015 |doi=10.1088/0004-637X/814/1/12 |volume=814 |issue=1 |journal=[[The Astrophysical Journal]] |page=12 |bibcode=2015ApJ...814...12V|s2cid=45438051 }}</ref>

<ref name="Johnson2016">{{cite journal |arxiv=1602.05200 |last1=Johnson |first1=Marshall C. |display-authors=etal |title=A 12-year Activity Cycle for the Nearby Planet Host Star HD 219134 |date=April 2016 |doi=10.3847/0004-637X/821/2/74 |volume=821 |issue=2 |journal=[[The Astrophysical Journal]] |page=74 |bibcode=2016ApJ...821...74J|s2cid=118651905 |doi-access=free }}</ref>

<ref name="Gillon2017">{{cite journal | title=Two massive rocky planets transiting a K-dwarf 6.5 parsecs away | last1=Gillon | first1=Michaël | last2=Demory | first2=Brice-Olivier | last3=Grootel | first3=Valérie | last4=Motalebi | first4=Fatemeh | last5=Lovis | first5=Christophe | last6=Cameron | first6=Andrew | last7=Charbonneau | first7=David | last8=Latham | first8=David | last9=Molinari | first9=Emilio | last10=Pepe | first10=Francesco | last11=Ségransan | first11=Damien | last12=Sasselov | first12=Dimitar | last13=Udry | first13=Stéphane | last14=Mayor | first14=Michel | last15=Micela | first15=Giuseppina | last16=Piotto | first16=Giampaolo | last17=Sozzetti | first17=Alessandro | display-authors=1 | journal=Nature Astronomy | volume=1 | at=0056 | year=2017 | issue=3 | arxiv=1703.01430 | doi=10.1038/s41550-017-0056 | bibcode=2017NatAs...1E..56G | s2cid=56075932 }}</ref>

<ref name="Hirsch2020">{{citation
 |title=Understanding the Impacts of Stellar Companions on Planet Formation and Evolution: A Survey of Stellar and Planetary Companions within 25 pc
 | display-authors=1 | last1=Hirsch | first1=Lea A.
 | last2=Rosenthal | first2=Lee | last3=Fulton | first3=Benjamin J.
 | last4=Howard | first4=Andrew W. | last5=Ciardi | first5=David R.
 | last6=Marcy | first6=Geoffrey W. | last7=Nielsen | first7=Eric L.
 | last8=Petigura | first8=Erik A. | last9=de Rosa | first9=Robert J.
 | last10=Isaacson | first10=Howard | last11=Weiss | first11=Lauren M.
 | last12=Sinukoff | first12=Evan | last13=Macintosh | first13=Bruce
 | journal=[[The Astronomical Journal]] | year=2021 | volume=161 | issue=3 | page=134 | postscript=.
 | doi=10.3847/1538-3881/abd639 | arxiv=2012.09190 | bibcode=2021AJ....161..134H | s2cid=229297873 | doi-access=free }}</ref>

<ref name="Rosenthal2021">{{cite journal |arxiv=2105.11583|doi=10.3847/1538-4365/abe23c|title=The California Legacy Survey. I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades|year=2021|last1=Rosenthal|first1=Lee J.|last2=Fulton|first2=Benjamin J.|last3=Hirsch|first3=Lea A.|last4=Isaacson|first4=Howard T.|last5=Howard|first5=Andrew W.|last6=Dedrick|first6=Cayla M.|last7=Sherstyuk|first7=Ilya A.|last8=Blunt|first8=Sarah C.|last9=Petigura|first9=Erik A.|last10=Knutson|first10=Heather A.|last11=Behmard|first11=Aida|last12=Chontos|first12=Ashley|last13=Crepp|first13=Justin R.|last14=Crossfield|first14=Ian J. M.|last15=Dalba|first15=Paul A.|last16=Fischer|first16=Debra A.|last17=Henry|first17=Gregory W.|last18=Kane|first18=Stephen R.|last19=Kosiarek|first19=Molly|last20=Marcy|first20=Geoffrey W.|last21=Rubenzahl|first21=Ryan A.|last22=Weiss|first22=Lauren M.|last23=Wright|first23=Jason T. |display-authors=1 |journal=The Astrophysical Journal Supplement Series|volume=255|issue=1|page=8|bibcode=2021ApJS..255....8R|s2cid=235186973 |doi-access=free }}</ref>

<ref name=SIMBAD>{{cite simbad | title=HR 8832 | access-date=2012-04-08 }}</ref>

}}

==External links==
* {{cite web |
title=BD+56 2966 / HR 8832 |
work=SolStation |
url=http://www.solstation.com/stars/hr8832.htm |
access-date=November 7, 2005 }}

{{HD 219134}}
{{Stars of Cassiopeia}}
{{2015 in space}}
{{Sky|23|13|16.98|+|57|10|06.1|100000}}

[[Category:Cassiopeia (constellation)]]
[[Category:Gliese and GJ objects|0892]]
[[Category:K-type main-sequence stars]]
[[Category:Solar-type stars|Gliese, 0892]]
[[Category:Suspected variables]]
[[Category:Henry Draper Catalogue objects|219134]]
[[Category:Bright Star Catalogue objects|8832]]
[[Category:Hipparcos objects|114622]]
[[Category:Durchmusterung objects]]
[[Category:Planetary systems with six confirmed planets]]
[[Category:Planetary transit variables]]