View source for HD 102956 b

{{Short description|Extrasolar planet in the constellation Ursa Major}}
{{Sky|11|51|23.0|+|57|38|27}}
{{Infobox planet
| name = HD 102956 b / Isagel
| image = File:Artistic impression of HD102956.png
| caption = Artist's impression HD 102956 b
<!-- DISCOVERY -->| discovery_ref = <ref name="Johnson2010"/>
| discoverer = Johnson ''et al.''
| discovery_site = [[Keck Observatory]]
| discovered = 2010
| discovery_method = [[Doppler spectroscopy]]
<!-- DESIGNATIONS -->
<!-- ORBITAL -->| orbit_ref = <ref name="Luhn2019"/>
| semimajor = {{val|0.0807|0.0073|ul=AU}}
| eccentricity = {{val|0.037|0.019}}
| period = {{val|6.49470|0.00019|u=days}}
| time_periastron = {{val|2455351.45|0.64|ul=JD}}
| arg_peri = {{val|301|33|u=º}}
| semi-amplitude = {{val|74.6|1.8|ul=m/s}}
| star = [[HD 102956]]
<!-- PHYS CHARS -->| physical_ref = <ref name="Luhn2019"/>
| mass = {{val|0.960|0.023|p=≥|ul=Jupiter mass}}
<!-- ATMOSPHERE -->
<!-- NOTES -->}}

{{Starbox begin
| name = HD 102956
}}
{{Starbox observe
| epoch = J2000
| constell = [[Ursa Major]]
| ra = {{RA|11|51|22.5111}}<ref name="Gaia DR2"/>
| dec = {{dec|+57|38|26.6427}}<ref name="Gaia DR2"/>
}}
{{Starbox character
| type = [[Main sequence]]
| class = A
}}
{{Starbox astrometry
| radial_v = {{val|-25|83}}
| prop_mo_ra = {{val|−11.24|0.049}}<ref name="Gaia DR2"/>
| prop_mo_dec = {{val|−17.578|0.049}}<ref name="Gaia DR2"/>
| parallax = 8.1753
| p_error = 0.0290
| parallax_footnote = <ref name="Gaia DR2"/>
| absmag_v = {{val|2.5}}
}}
{{Starbox detail
| mass = {{val|1.68|0.11}}
| radius = {{val|4.4|0.1}}
| luminosity_visual = {{val|11.6|0.5}}
| temperature = {{val|5054|44}}
| metal_fe = {{val|+0.19|0.04}}
| rotational_velocity = 0.30
}}
{{Starbox catalog
| names = {{odlist | 2MASS=J11512253+5738267 | BD=+58 1340 | HIP=57820 | SAO=28161 | TYC=3839-00846-1 }}<ref name="Simbad"/>
}}
{{Starbox reference
| Simbad = HD+102956
| NSTED = HD102956
}}
{{Starbox end}}

'''HD 102956 b''' or '''Isagel''' is an [[extrasolar planet]] discovered in 2010 by a team of American astronomers led by [[John Johnson (astronomer)|John Johnson]] using [[Doppler spectroscopy]] and the [[Keck Observatory]] in [[Hawaii]]. HD 102956 b is in the orbit of host star [[HD 102956]]. The planet is at most the mass of Jupiter, orbiting every 6.5 days at a distance of 12 million km. HD 202956 b has a very circular orbit.<ref name="Johnson2010"/> The system is roughly 399 light years from us.

==Discovery and nomenclature==
[[File:HD102956b_location.png|thumb|left|HD 102956 is located inside the Big Dipper.]] The name HD 102956 derives directly from the fact that the star is the 102,956th star catalogued in the [[Henry Draper catalog]]. The designation of b is given to the first planet orbiting a given star.

The star is one of the 2.5 million brightest stars in the sky and is part of the [[Tycho-2 Catalogue]]. It is not visible to the naked eye with an [[apparent magnitude]] of 8.

===NameExoWorlds===
In 2019 this planet was announced as part of the [[IAU]] [[NameExoWorlds]] project<ref name=ExoWorlds>{{cite web |url=http://www.nameexoworlds.iau.org/sweden |title=Name an exoplanet (press release) |date=2019-06-06 |access-date=2019-06-13 |archive-date=2019-06-08 |archive-url=https://web.archive.org/web/20190608152931/http://www.nameexoworlds.iau.org/sweden |url-status=dead }}</ref> where it was designated as the planet that will be named by [[Sweden]]. The winning proposal was ''Isagel'', from Nobel laureate [[Harry Martinson]]'s space poem ''[[Aniara]]''.<ref name=Forskning&Framsteg>{{cite web |url=https://fof.se/artikel/rymddikt-gav-namn-sveriges-exoplanet |title=Rymddikt gav namn åt Sveriges exoplanet |date=2019-12-17 |access-date=2021-08-10 |language=Swedish |archive-date=2020-01-12 |archive-url=https://web.archive.org/web/20200112094443/https://fof.se/artikel/rymddikt-gav-namn-sveriges-exoplanet |url-status=dead }}</ref>

==Host star==
HD 102956 (''Aniara'') is an orange [[subgiant]] with a mass and radius of 1.68 {{Solar mass|link=y}} and 4.4 {{Solar radius|link=y}}, respectively. The surface temperature is about {{convert|5054|K|C}}. The star is 11.6 times brighter than the Sun. The star's age is estimated at 2.3 billion years.

==References==
{{reflist|refs=

<ref name="Gaia DR2">{{Cite Gaia DR2|845335158256083584}}</ref>

<ref name="Johnson2010">{{cite journal | title=A Hot Jupiter Orbiting the 1.7 M☉ Subgiant HD 102956 | last1=Johnson | first1=John Asher | last2=Bowler | first2=Brendan P. | last3=Howard | first3=Andrew W. | last4=Henry | first4=Gregory W. | last5=Marcy | first5=Geoffrey W. | last6=Isaacson | first6=Howard | last7=Brewer | first7=John Michael | last8=Fischer | first8=Debra A. | last9=Morton | first9=Timothy D. | last10=Crepp | first10=Justin R. | display-authors=1 | journal=The Astrophysical Journal Letters | volume=721 | issue=2 | pages=L153–L157 | year=2010 | arxiv=1007.4555 | bibcode=2010ApJ...721L.153J | bibcode-access=free | doi=10.1088/2041-8205/721/2/L153 | doi-access=free }}</ref>

<ref name="Luhn2019">{{cite journal | title=Retired A Stars and Their Companions. VIII. 15 New Planetary Signals around Subgiants and Transit Parameters for California Planet Search Planets with Subgiant Hosts | last1=Luhn | first1=Jacob K. | last2=Bastien | first2=Fabienne A. | last3=Wright | first3=Jason T. | last4=Johnson | first4=John A. | last5=Howard | first5=Andrew W. | last6=Isaacson | first6=Howard | display-authors=1 | journal=The Astronomical Journal | volume=157 | issue=4 | at=149 | year=2019 | arxiv=1811.03043 | bibcode=2019AJ....157..149L | doi=10.3847/1538-3881/aaf5d0 | s2cid=102486961 | doi-access=free }}</ref>

<ref name="Simbad">{{cite simbad | title=HD 102956 | access-date=2019-09-21 }}</ref>

}}

{{Sky|11|51|23.0|+|57|38|27}}

[[Category:Exoplanets discovered in 2010]]
[[Category:Giant planets]]
[[Category:Ursa Major]]
[[Category:Exoplanets detected by radial velocity]]
[[Category:Exoplanets with proper names]]