HD 44219
Star in the constellation Monoceros
From Wikipedia, the free encyclopedia
HD 44219 is a solar-type star[9] with an exoplanetary companion in the equatorial constellation of Monoceros. It has an apparent visual magnitude of 7.69,[1] making it an 8th magnitude star that is too faint to be readily visible to the naked eye. The system is located at a distance of 173 light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −12 km/s.[2]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Monoceros[1] |
| Right ascension | 06h 20m 14.32321s[2] |
| Declination | −10° 43′ 30.0310″[2] |
| Apparent magnitude (V) | 7.69[1] |
| Characteristics | |
| Spectral type | G3V[3] |
| Apparent magnitude (B) | 8.377[1] |
| Apparent magnitude (J) | 6.509±0.029[1] |
| Apparent magnitude (H) | 6.215±0.038[1] |
| Apparent magnitude (K) | 6.115±0.017[1] |
| B−V color index | 0.687±0.007[1] |
| Astrometry | |
| Radial velocity (Rv) | −12.17±0.25[2] km/s |
| Proper motion (μ) | RA: 72.349[2] mas/yr Dec.: −16.568[2] mas/yr |
| Parallax (π) | 18.8732±0.0638 mas[2] |
| Distance | 172.8 ± 0.6 ly (53.0 ± 0.2 pc) |
| Absolute magnitude (MV) | 4.18[1] |
| Details | |
| Mass | 1.01±0.01[4] M☉ |
| Radius | 1.37±0.03[4] R☉ |
| Luminosity | 1.83±0.01[4] L☉ |
| Surface gravity (log g) | 4.17±0.02[4] cgs |
| Temperature | 5,749±45[4] K |
| Metallicity [Fe/H] | 0.04±0.01[5] dex |
| Rotational velocity (v sin i) | 1.524[6] km/s |
| Age | 5.40[7] 9.6±0.7[4] Gyr |
| Other designations | |
| BD−10°1479, HD 44219, HIP 30114, SAO 151367, PPM 217031[8] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Characteristics
This is an ordinary G-type main-sequence star with a stellar classification of G3V.[3] L. Casagrande and associates in 2011 estimated the age of the star as 5.4 billion years,[7] while A. Bonfanti and colleagues listed a much greater age of nearly 10 billion years in 2015.[4] It has a near solar metallicity and is spinning with a projected rotational velocity of 1.5 km/s.[5] The star has about the same mass as the Sun but is 37% larger in radius. It is radiating 1.83 times the luminosity of the Sun from its photosphere at an effective temperature of 5,749 K.[4]
Planetary system
In 2009, a Jovian planet was found in a highly eccentric orbit around the star by the HARPS planet search program. There is some evidence of an additional, longer-period companion.[9]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 0.58+0.06 −0.04 MJ |
1.19±0.02 | 472.3+6.3 −5.0 |
0.61+0.07 −0.09 |
— | — |