HD 9446
Star with a planetary system in the constellation Triangulum
title: "HD 9446" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["g-type-main-sequence-stars", "planetary-systems-with-two-confirmed-planets", "triangulum", "durchmusterung-objects", "henry-draper-catalogue-objects", "hipparcos-objects"] description: "Star with a planetary system in the constellation Triangulum" topic_path: "science/astronomy" source: "https://en.wikipedia.org/wiki/HD_9446" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Star with a planetary system in the constellation Triangulum ::
| epoch = J2000 | constell = Triangulum | ra = | dec = | appmag_v = 8.35 | type = | class = G5V | b-v = | u-b = | variable = | radial_v = | prop_mo_ra = | prop_mo_dec = | parallax = 19.9200 | p_error = 0.0413 | parallax_footnote = | absmag_v = 4.76 | mass = | radius = | gravity = | luminosity = 1.1 | temperature = | metal_fe = | age_gyr = | rotational_velocity = | names = | Simbad = HD+9446 | NSTED = HD 9446 | EPE = HD+9446 HD 9446 is a star located about 164 light-years away in the constellation of Triangulum, near the southwestern constellation border with Pisces. This object can be viewed with binoculars or a telescope, but it is too faint to be seen with the naked eye at its apparent visual magnitude of 8.35. It is drifting further away from the Sun with a radial velocity of +21 km/s.
This object is a G-type main sequence star with a stellar classification of G5V. The physical properties this star appear similar to the Sun, making it a candidate solar analog. However, the measured abundance of elements with more mass than helium is outside the accepted range. It is roughly two billion years in age and has an active chromosphere. The amount of activity measured in the chromosphere corresponds to a star with a rotation period of about 10 days.
On 5 January 2010, scientists announced the discovery of two planets orbiting around HD 9446. In addition, another exoplanet candidate is detected by astrometry in 2024.
| table_ref = | exoplanet = b | mass = ≥ | period = | semimajor = | eccentricity = | exoplanet = c | mass = ≥ | period = | semimajor = | eccentricity = | exoplanet = d | mass = 1.5 | semimajor = 7.0 | period = | eccentricity =
References
| last1=Anderson | first1=E. | last2=Francis | first2=Ch. | title=XHIP: An extended hipparcos compilation | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | arxiv=1108.4971 | doi=10.1134/S1063773712050015 | s2cid=119257644 }}
| title=Revising the ages of planet-hosting stars | url=http://www.aanda.org/articles/aa/full_html/2015/03/aa24951-14/aa24951-14.html | last1=Bonfanti | first1=A. | last2=Ortolani | first2=S. | last3=Piotto | first3=G. | last4=Nascimbeni | first4=V. | display-authors=1 | journal=Astronomy and Astrophysics | volume=575 | at=A18 | year=2015 | arxiv=1411.4302 | bibcode=2015A&A...575A..18B | doi=10.1051/0004-6361/201424951 | s2cid=54555839
|doi=10.1051/0004-6361/200913790 |last1=Hébrard |first1=Guillaume |last2=Bonfils |first2=Xavier |last3=Ségransan |first3=Damien |last4=Moutou |first4=Claire |last5=Delfosse |first5=Xavier |last6=Bouchy |first6=François |last7=Boisse |first7=Isabelle |last8=Arnold |first8=Luc |date=2010 |title=The SOPHIE Search for Northern Extrasolar Planets: II. A Multi-planet System Around HD 9446 |journal=Astronomy & Astrophysics |volume=513 |pages=A69 |url=http://www.aanda.org/articles/aa/full_html/2010/05/aa13790-09/aa13790-09.html |bibcode=2010A&A...513A..69H |arxiv=1001.0682 |s2cid=119306916 }}
| last1=Meléndez | first1=J. | last2=Schuster | first2=W. J. | last3=Silva | first3=J. S. | last4=Ramírez | first4=I. | last5=Casagrande | first5=L. | last6=Coelho | first6=P. | title=uvby-β photometry of solar twins. The solar colors, model atmospheres, and the Teff and metallicity scales | display-authors=1 | journal=Astronomy and Astrophysics | volume=522 | pages=A98 | date=November 2010 | bibcode=2010A&A...522A..98M | arxiv=1007.5351 | doi=10.1051/0004-6361/201014741 | s2cid=118481647 | url=https://zenodo.org/record/998268 }}
References
- "HD 9446".
- {{Cite Gaia DR3. 302956655074266112
- (2020-05-01). "Orbital Refinement and Stellar Properties for the HD 9446, HD 43691, and HD 179079 Planetary Systems". The Astronomical Journal.
- (2024). "Searching for substellar companion candidates with Gaia. II. A catalog of 9,698 planet candidate solar-type hosts". Astronomy and Astrophysics.
::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::