Summary
HD 109749 is a binary star system about 206 light years away in the constellation of Centaurus. The pair have a combined apparent visual magnitude of 8.08,[2] which is too faint to be visible to the naked eye. The primary component has a close orbiting exoplanet companion. The system is drifting closer with a heliocentric radial velocity of −13.2 km/s.[2]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 12h 37m 16.379s[1] |
| Declination | −40° 48′ 43.63″[1] |
| Apparent magnitude (V) | 8.08[2] |
| Characteristics | |
| Spectral type | G3 IV[3] or G3 V + K5 V[4] |
| B−V color index | 0.714±0.021[2] |
| Astrometry | |
| Radial velocity (Rv) | −13.24±0.18[2] km/s |
| Proper motion (μ) | RA: −157.308 mas/yr[1] Dec.: −6.357 mas/yr[1] |
| Parallax (π) | 15.8134 ± 0.0263 mas[1] |
| Distance | 206.3 ± 0.3 ly (63.2 ± 0.1 pc) |
| Absolute magnitude (MV) | 4.34[2] |
| Details | |
| HD 109749 A | |
| Mass | 1.10[5] M☉ |
| Radius | 1.21±0.02[6] R☉ |
| Luminosity | 1.55±0.02[6] L☉ |
| Surface gravity (log g) | 4.32±0.02[6] cgs |
| Temperature | 5,860±39[6] K |
| Metallicity [Fe/H] | 0.25±0.05[3] dex |
| Rotation | 34 d[3] |
| Rotational velocity (v sin i) | 2.5±0.5[3] km/s |
| Age | 4.10±0.70[6] Gyr |
| HD 109749 B | |
| Mass | 0.78[5] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
The primary component, HD 109749 A, is a G-type subgiant star with a spectral type of G3IV,[3] indicating it is an evolved star with a luminosity higher than that of a main sequence star. It has a mass of 1.14 M☉ and a radius of 1.21 R☉. The star is shining with a luminosity of 1.55 L☉ and has an effective temperature of 5,860 K. Evolutionary models estimate an age of 4.1 billion years.[6] HD 109749 A is chromospherically inactive and has a high metallicity, with an iron abundance 178% of Sun's.[3]
The secondary, HD 109749 B, is a K-type main sequence star with an apparent magnitude of 10.3.[8] It has a mass of about 0.78 M☉ and is located at a separation of 8.4 arcseconds, which corresponds to a projected separation of 490 AU.[5] This star has the same proper motion as the primary and seems to be at the same distance, confirming they form a physical binary system.[9]
Planetary system edit
In 2005, an exoplanet was discovered around HD 109749 A. It was detected by the radial velocity method as part of the N2K Consortium. It is a hot Jupiter with a minimum mass of 0.28 MJ and a semimajor axis of 0.06 AU.[3]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| Ab | ≥0.27±0.045 MJ | 0.0615±0.004 | 5.239891±0.000099 | 0 (fixed) | — | — |
See also edit
References edit
- ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d e f 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 c d e f g Fischer, Debra A.; et al. (2006). "The N2K Consortium. III. Short-Period Planets Orbiting HD 149143 and HD 109749". The Astrophysical Journal. 637 (2): 1094–1101. Bibcode:2006ApJ...637.1094F. doi:10.1086/498557.
- ^ Lu, P. K. (April 1982). "Spectral classification and DD photometry of a southern group of stars with common motions. I." Publications of the Astronomical Society of the Pacific. 94: 304–316. Bibcode:1982PASP...94..304L. doi:10.1086/130981.
- ^ a b c Quarles, Billy; et al. (2020), "Orbital Stability of Circumstellar Planets in Binary Systems", The Astronomical Journal, 159 (3): 80, arXiv:1912.11019, Bibcode:2020AJ....159...80Q, doi:10.3847/1538-3881/ab64fa, S2CID 209444271
- ^ a b c d e f Bonfanti, A.; et al. (2016). "Age consistency between exoplanet hosts and field stars". Astronomy and Astrophysics. 585. A5. arXiv:1511.01744. Bibcode:2016A&A...585A...5B. doi:10.1051/0004-6361/201527297. S2CID 53971692.
- ^ "HD 109749". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-12-19.
- ^ "HD 109749B". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-01-20.
- ^ Desidera, S.; Barbieri, M. (January 2007). "Properties of planets in binary systems. The role of binary separation". Astronomy and Astrophysics. 462 (1): 345–353. arXiv:astro-ph/0610623. Bibcode:2007A&A...462..345D. doi:10.1051/0004-6361:20066319. S2CID 13813761.
- ^ Ment, Kristo; et al. (2018). "Radial Velocities from the N2K Project: Six New Cold Gas Giant Planets Orbiting HD 55696, HD 98736, HD 148164, HD 203473, and HD 211810". The Astronomical Journal. 156 (5). 213. arXiv:1809.01228. Bibcode:2018AJ....156..213M. doi:10.3847/1538-3881/aae1f5. S2CID 119243619.