HD 109749

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]
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
CD−40 7393, Gaia DR2 6147000074988843264, HD 109749, HIP 61595, SAO 223556, WDS J12373-4049, 2MASS J12371639-4048435 [7]
Database references
SIMBAD	data

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 M_J 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

• HD 149143
• List of extrasolar planets

References

1. 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. 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. 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. 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. 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.