View source for HD 221287 b

{{Short description|Exoplanet in the constellation Tucana}}
{{Infobox planet
| name = HD 221287 b / Pipitea
<!-- DISCOVERY           -->| discoverer = {{ill|Dominique Naef|fr}} ''et al.''<ref name="Naef2007"/>
| discovery_site = {{flag|Chile}}
| discovered = March 5, 2007
| discovery_method = [[HARPS]]
<!-- DESIGNATIONS        -->
<!-- ORBITAL             -->| apsis = astron
| aphelion = {{convert|1.35|AU|km|abbr=on}}
| perihelion = {{convert|1.15|AU|km|abbr=on}}
| semimajor = {{convert|1.25|±|0.04|AU|km|abbr=on}}
| eccentricity = 0.08 ± 0.11
| period = 456.1 ± 6.5 [[day|d]]<br>1.2487 [[year|y]]
| time_periastron = 2,453,263 ± 100
| arg_peri = 98 ± 72
| semi-amplitude = 71 ± 13
| star = [[HD 221287]]
<!-- PHYS CHARS          -->| mass = >3.12 ± 0.78 {{Jupiter mass|link=y}}<br>(992 {{Earth mass|link=y}})
<!-- ATMOSPHERE          --> 
<!-- NOTES               -->}}
'''HD 221287 b''', also known as '''Pipitea''', is an [[exoplanet]] that orbits [[HD 221287]], approximately 173 [[light year]]s away in the [[constellation]] of [[Tucana]]. This planet has [[mass]] >3.12 M<sub>J</sub> (>992 M<sub>🜨</sub>) and orbits in a [[habitable zone]] at 1.25 [[astronomical unit|AUs]] (6.06 [[microparsec|μpc]]) from the star, taking 1.25 years to orbit at 29.9 [[kilometers per second|km/s]] around the star. {{ill|Dominique Naef|fr}} discovered this planet in early 2007 by using [[HARPS]] [[spectrograph]] located in [[Chile]].<ref name="Naef2007"/>

Based on a probable 10<sup>−4</sup> fraction of the planet mass as a satellite,<ref>[[Robin Canup|Canup R.M.]], Ward W.R. (2006). A common mass scaling for satellite systems of gaseous planets. Nature, 441: 834-839.</ref> the planet can have a [[Mars]]-sized moon with habitable surface.<ref>{{Cite web |url=http://phl.upr.edu/projects/habitable-exoplanets-catalog/data |title=The Habitable Exoplanets Catalog: Data of Potential Habitable Worlds |access-date=2013-06-23 |archive-date=2017-12-01 |archive-url=https://web.archive.org/web/20171201032102/http://phl.upr.edu/projects/habitable-exoplanets-catalog/data |url-status=dead }}</ref> On the other hand, this mass can be distributed into many small satellites as well.

It was named "Pipitea" by representatives of the [[Cook Islands]] in the [[IAU]]'s 2019 [[NameExoWorlds]] contest, with the comment "Pipitea is a small, white and gold pearl found in Penrhyn lagoon in the northern group of the Cook Islands."<ref name="IAU Approved">{{cite web|url=http://www.nameexoworlds.iau.org/final-results|title=Approved names (§ Cook Islands)|website=Name Exo Worlds|publisher=[[IAU]]|accessdate=19 December 2019}}</ref>

== Insolation data for HD 221287 b ==
{{further|Luminosity|Climate model#Zero-dimensional models}}

From Luminosity and distance irridance can be calculated: <ref group="note">From <math>\begin{smallmatrix}L=4 \pi R^2 \sigma T_{\rm eff}^4 \end{smallmatrix}</math>, where <math>\begin{smallmatrix}L \end{smallmatrix}</math> is the luminosity, <math>\begin{smallmatrix}R \end{smallmatrix}</math> is the radius, <math>\begin{smallmatrix}T_{\rm eff}\end{smallmatrix}</math> is the effective surface temperature and <math>\begin{smallmatrix}\sigma \end{smallmatrix}</math> is the [[Stefan–Boltzmann constant]].</ref>
{| class="wikitable"	
|- align="center" style="align:center; background:#ffc0c0"	
 ! Planet Distance || [[Insolation]] (W/m<sup>2</sup>)   || % of Earth's	
|-
| Earth's Aphelion Flux ||1321.544|| 96.74%
|-
| '''HD 221287 b''' [[Apastron]] flux ||1,351.050 ||	98.90%	
|-
| Earth's Average Flux <ref group="note">Earth's [[Solar constant|Solar Constant.]]</ref>||1366.079|| 100.00%
|-
| Earth's Perihelion Flux ||1412.903 || 103.43%
|-
| '''HD 221287 b''' [[Semimajor Axis|Average]] flux <ref group="note"><math>f_p= \frac{ (1.80245\times 3.0572\times 10^{25})} { ( ( 1.25 - ( 1.25 \times 0.08 ) ) \times 149597870700 )^2 }</math></ref>|| 1,575.865  ||	115.36%
|-
|'''HD 221287 b''' [[Periastron]] flux ||1,861.844		||136.29%
|-	
| Venus' Aphelion Flux ||2585.411||188.72%	
|-
| Venus' Average Flux ||2620.693||191.30%
|-
| Venus' Perihelion Flux ||2656.70||193.93%
|-
|}
{{clear}}

== See also ==
* [[HD 100777 b]]
* [[HD 190647 b]]

==Notes==
<references group="note"/>

== References ==
{{Reflist|refs=

<ref name="Naef2007">{{Cite journal | title=The HARPS search for southern extra-solar planets IX. Exoplanets orbiting HD 100777, HD 190647, and HD 221287 | url=http://www.aanda.org/articles/aa/full/2007/29/aa7361-07/aa7361-07.html | last1=Naef | first1=D. | last2=Mayor | first2=M. | last3=Benz | first3=W. | last4=Bouchy | first4=F. | last5=Lo Curto | first5=G. | last6=Lovis | first6=C. | last7=Moutou | first7=C. | last8=Pepe | first8=F. | last9=Queloz | first9=D. | last10=Santos | first10=N. C. | last11=Udry | first11=S. | display-authors=1 | journal=Astronomy and Astrophysics | volume=470 | issue=2 | pages=721–726 | year=2007 | arxiv=0704.0917 | bibcode=2007A&A...470..721N | doi=10.1051/0004-6361:20077361 }}</ref>

}}

== External links ==
*{{cite encyclopedia|url=https://exoplanet.eu/catalog/hd_221287_b--372/|encyclopedia=[[Extrasolar Planets Encyclopaedia]]|title=Notes for planet HD 221287 b|access-date=2008-07-21}}
{{Sky|23|31|20.3389|-|58|12|35.038|172.502}}

{{Tucana}}

[[Category:Giant planets]]
[[Category:Tucana]]
[[Category:Exoplanets discovered in 2007]]
[[Category:Exoplanets detected by radial velocity]]
[[Category:Giant planets in the habitable zone]]
[[Category:Exoplanets with proper names]]


{{extrasolar-planet-stub}}

[[es:HD 221287#Sistema planetario]]