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,[2] 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.[1]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Monoceros |
| Right ascension | 06h 20m 14.32321s[1] |
| Declination | −10° 43′ 30.0310″[1] |
| Apparent magnitude (V) | 7.69[2] |
| Characteristics | |
| Spectral type | G3V[3] |
| Apparent magnitude (B) | 8.377[2] |
| Apparent magnitude (J) | 6.509±0.029[2] |
| Apparent magnitude (H) | 6.215±0.038[2] |
| Apparent magnitude (K) | 6.115±0.017[2] |
| B−V color index | 0.687±0.007[2] |
| Astrometry | |
| Radial velocity (Rv) | −12.17±0.25[1] km/s |
| Proper motion (μ) | RA: 72.349[1] mas/yr Dec.: −16.568[1] mas/yr |
| Parallax (π) | 18.8732 ± 0.0638 mas[1] |
| Distance | 172.8 ± 0.6 ly (53.0 ± 0.2 pc) |
| Absolute magnitude (MV) | 4.18[2] |
| 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 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Characteristics
editThis 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
editIn 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 |
— | — |
See also
editReferences
edit- ^ a b c d e f g 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.
- ^ a b c d e f g h 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.
- ^ a b Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey. 5. Bibcode:1999MSS...C05....0H.
- ^ a b c d e f g h Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951. S2CID 54555839.
- ^ a b Delgado Mena, E.; et al. (October 2017). "Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program. II. Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Eu". Astronomy & Astrophysics. 606: 20. arXiv:1705.04349. Bibcode:2017A&A...606A..94D. doi:10.1051/0004-6361/201730535. S2CID 118908425. A94.
- ^ Costa Silva, A. R.; et al. (February 2020). "Chemical abundances of 1111 FGK stars from the HARPS-GTO planet search sample. III. Sulfur". Astronomy & Astrophysics. 634: 10. arXiv:1912.08659. Bibcode:2020A&A...634A.136C. doi:10.1051/0004-6361/201936523. S2CID 209405391. A136.
- ^ a b Casagrande, L.; et al. (June 2011). "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey". Astronomy & Astrophysics. 530 (A138): 21. arXiv:1103.4651. Bibcode:2011A&A...530A.138C. doi:10.1051/0004-6361/201016276. S2CID 56118016.
- ^ "HD 44219". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-10-21.
- ^ a b c Naef, Dominique; et al. (2010). "The HARPS Search for Southern Extrasolar Planets XXIII. 8 Planetary Companions to Low-activity Solar-type Stars". Astronomy and Astrophysics. 523: A15. arXiv:1008.4600. Bibcode:2010A&A...523A..15N. doi:10.1051/0004-6361/200913616. S2CID 118845989.