HD 50499

HD 50499

Observation data Epoch J2000      Equinox J2000
Constellation	Puppis
Right ascension	06^h 52^m 02.02432^s[1]
Declination	−33° 54′ 56.0164″[1]
Apparent magnitude (V)	7.21[2]
Characteristics
Spectral type	G0/2 V[3]
B−V color index	0.614±0.008[2]
Astrometry
Radial velocity (Rv)	+36.69±0.09[2] km/s
Proper motion (μ)	RA: −69.326[1] mas/yr Dec.: +68.089[1] mas/yr
Parallax (π)	21.5765 ± 0.0258 mas[1]
Distance	151.2 ± 0.2 ly (46.35 ± 0.06 pc)
Absolute magnitude (MV)	3.89[2]
Details[4]
Mass	1.31±0.07 M☉
Radius	1.42±0.02 R☉
Luminosity	2.38±0.005 L☉
Surface gravity (log g)	4.42±0.05 cgs
Temperature	6,099±43 K
Metallicity [Fe/H]	0.38±0.03 dex
Rotation	22.4±1.0 d
Rotational velocity (v sin i)	4.313 km/s
Age	2.40±0.56[4] or 6.17[5] Gyr
Other designations
CD−33°3304, GC 9010, HD 50499, HIP 32970, SAO 197294[6]
Database references
SIMBAD	data

HD 50499 is a star in the constellation of constellation of Puppis. With an apparent visual magnitude of 7.21,^[2] this star is too faint to be in naked eye visibility. It is located at a distance of 151 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +36.7 km/s.^[2]

This object is a G-type main-sequence star with a stellar classification of G0/2 V.^[3] It is positioned 0.6 magnitudes above the main sequence, which may be explained by a high metallicity and an older age.^[5] Vogt et al. (2005) estimated its age as about 6.2 billion years,^[5] although more recent estimates give a younger age of around 2.4^[4] billion years. The star has 1.31 times the mass of the Sun and 1.42 times the Sun's radius. It is radiating 2.38 times the luminosity of the Sun from its photosphere at an effective temperature of 6,099 K.^[4] As of 2019, two exoplanets have been confirmed to be orbiting the star.^[4]

Planetary system

The first planet discovered, HD 50499 b, is a gas giant with mass of 1.7 times Jupiter. It is a long period, taking 6.8 years to orbit the star. The planet's eccentric orbit passes through the average distance of 3.93 AU.

The planet was discovered by four team members including Steven Vogt in 2005 using their radial velocity method, which used to measure changes in red- and blue-shifting of the star that indicate the presence of planets caused by gravitational tug.^[5] There is also a linear trend in the radial velocities, which may indicate an additional outer planet. The best two-planet model gives a different period and mass for the inner planet (9.8 years and 3.4 Jupiter masses), with an outer planet of 2.1 Jupiter masses in a 37-year orbit. However the two-planet model does not represent a significant improvement over the model with one planet and a linear trend, so more observations are needed to constrain the parameters of the outer planet.

Rickman et al. (2019) gave an updated model of the planet and its orbit, and confirmed the presence of a second planet, HD 50499 c, with a period of about 24 years.^[4]

The HD 50499 planetary system^[4]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥1.45±0.08 MJ	3.93±0.07	2483.7±18.3	0.27+0.04 −0.03	—	—
c	≥2.93+0.73 −0.18 MJ	9.02+1.73 −0.33	8619.9+2622.5 −405.4	0.00+0.14 −0.02	—	—

See also

• HD 50554

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
2. Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
3. Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 3. Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan. Bibcode:1982mcts.book.....H.
4. Rickman, E. L.; et al. (May 2019). "The CORALIE survey for southern extrasolar planets. XVIII. Three new massive planets and two low-mass brown dwarfs at greater than 5 AU separation". Astronomy & Astrophysics. 625: 16. arXiv:1904.01573. Bibcode:2019A&A...625A..71R. doi:10.1051/0004-6361/201935356. S2CID 91184450. A71.
5. Vogt, Steven S.; et al. (2005). "Five New Multicomponent Planetary Systems" (PDF). The Astrophysical Journal. 632 (1): 638–658. Bibcode:2005ApJ...632..638V. doi:10.1086/432901. S2CID 16509245.
6. "HD 50499". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-01-05.