HD 4313

{{short description|Star in the constellation of Pisces}}

{{Starbox begin

| name = HD 4313

}}

{{Starbox observe

| epoch = J2000.0

| constell = Pisces

| ra = {{RA|00|45|40.3578}}

| dec = {{DEC|+07|50|42.075}}

| appmag_v = 7.83{{cite journal | 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 }}

}}

{{Starbox character

| type = Subgiant

| class = K2 IV{{cn|date=December 2023}}

| b-v = 0.963{{±|0.017}}

| u-b =

| variable =

}}

{{Starbox astrometry

| radial_v = 14.48{{±|0.23}}

| prop_mo_ra = −6.281

| prop_mo_dec = 6.566

| pm_footnote =

| parallax = 7.3090

| p_error = 0.0879

| parallax_footnote = {{cite Gaia EDR3|2557541493057378048}}

| absmag_v = 2.17

}}

{{Starbox detail

| source =

| mass = 1.61{{±|0.13|0.12}}{{cite journal |arxiv=2006.07649 |doi=10.1093/mnras/staa1793 |title=Asteroseismic masses of four evolved planet-hosting stars using SONG and TESS: Resolving the retired A-star mass controversy |year=2020 |last1=Malla |first1=Sai Prathyusha |last2=Stello |first2=Dennis |last3=Huber |first3=Daniel |last4=Montet |first4=Benjamin T. |last5=Bedding |first5=Timothy R. |last6=Fredslund Andersen |first6=Mads |last7=Grundahl |first7=Frank |last8=Jessen-Hansen |first8=Jens |last9=Hey |first9=Daniel R. |last10=Palle |first10=Pere L. |last11=Deng |first11=Licai |last12=Zhang |first12=Chunguang |last13=Chen |first13=Xiaodian |last14=Lloyd |first14=James |last15=Antoci |first15=Victoria |journal=Monthly Notices of the Royal Astronomical Society |volume=496 |issue=4 |pages=5423–5435 |doi-access=free }}

| radius = 5.15{{±|0.18|0.17}}

| luminosity = 15.81

| temperature = 4,966{{±|40}}

| gravity = 3.24{{Cite web | title=Exoplanet Archive | url=https://exoplanetarchive.ipac.caltech.edu/overview/HD%204313#star_HD-4313_collapsible | access-date=2020-12-11 | website=exoplanetarchive.ipac.caltech.edu }}

| metal_fe = 0.05{{±|0.10}}{{cite journal |arxiv=1708.00716 |doi=10.1093/mnras/stx2009 |title=The masses of retired a stars with asteroseismology: Kepler and K2 observations of exoplanet hosts |year=2017 |last1=North |first1=Thomas S. H. |last2=Campante |first2=Tiago L. |last3=Miglio |first3=Andxsrea |last4=Davies |first4=Guy R. |last5=Grunblatt |first5=Samuel K. |last6=Huber |first6=Daniel |last7=Kuszlewicz |first7=James S. |last8=Lund |first8=Mikkel N. |last9=Cooke |first9=Benjamin F. |last10=Chaplin |first10=William J. |journal=Monthly Notices of the Royal Astronomical Society |volume=472 |issue=2 |pages=1866–1878 |doi-access=free }}

| rotational_velocity=1.91±0.25

| age_gyr = 2.03{{±|0.64|0.45}}

}}

{{Starbox catalog

| names = {{odlist| HD=4313 | HIP=3574 | BD=+07°104 | 2MASS=J00454035+0750421 | Gaia DR2=2557541493057378048 }}{{cite simbad | title=HD 4313 | access-date=2023-12-11 }}

}}

{{Starbox reference

| Simbad=HD+4313

}}

{{Starbox end}}

HD 4313 is a star with an orbiting exoplanetary companion in the constellation of Pisces. It has an apparent visual magnitude of 7.83, which is too faint to be reading visible to the unaided eye. The system is located at a distance of 446 light years based on parallax, and is drifting further away with a radial velocity of 14.5 km/s. This is a single star, which means it has no binary partners, at least in range of projected separations from 6.85 to 191.78 AU.{{cite journal |arxiv=1709.05315 |doi=10.3847/1538-3881/aa8d69 |title=Exclusion of Stellar Companions to Exoplanet Host Stars |year=2017 |last1=Wittrock |first1=Justin M. |last2=Kane |first2=Stephen R. |last3=Horch |first3=Elliott P. |last4=Howell |first4=Steve B. |last5=Ciardi |first5=David R. |last6=Everett |first6=Mark E. |journal=The Astronomical Journal |volume=154 |issue=5 |page=184 |bibcode=2017AJ....154..184W |s2cid=55789971 |doi-access=free }} It hosts an extrasolar planet.

This is an aging K-type star with a mass of nearly twice the Sun, although different methods give mass estimates which differ as much as {{Solar_mass|0.5}}. It is a swollen star with 5.14 times the radius of the Sun, and has a cool effective temperature of 4,966{{±|40}} k. The "IV" in the spectral class means it's a K-type subgiant star which has exhausted the hydrogen at its core, and cooling and expanding to become a red giant. It is around two billion years in age and is spinning with a projected rotational velocity of 1.9 km/s.