HD 109749
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]
Distance206.3 ± 0.3 ly
(63.2 ± 0.1 pc)
Absolute magnitude (MV)4.34[2]
Details
HD 109749 A
Mass1.10[5] M☉
Radius1.21±0.02[6] R☉
Luminosity1.55±0.02[6] L☉
Surface gravity (log g)4.32±0.02[6] cgs
Temperature5,860±39[6] K
Metallicity [Fe/H]0.25±0.05[3] dex
Rotation34 d[3]
Rotational velocity (v sin i)2.5±0.5[3] km/s
Age4.10±0.70[6] Gyr
HD 109749 B
Mass0.78[5] M☉
Other designations
CD−40 7393, Gaia DR2 6147000074988843264, HD 109749, HIP 61595, SAO 223556, WDS J12373-4049, 2MASS J12371639-4048435[7]
Database references
SIMBADdata

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]

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

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]

The HD 190949 A planetary system[10]
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

References

  1. ^ 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.
  2. ^ 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.
  3. ^ 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.
  4. ^ 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.
  5. ^ 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
  6. ^ 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.
  7. ^ "HD 109749". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-12-19.
  8. ^ "HD 109749B". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-01-20.
  9. ^ 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.
  10. ^ 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.


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