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]
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]

  1. ^ a b c d Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  3. ^ a b c d e f Cite error: The named reference Fischer2006 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Lu_1982 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Quarles2019 was invoked but never defined (see the help page).
  6. ^ a b c d e f Cite error: The named reference Bonfanti2016 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Simbad was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD2 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Desidera2007 was invoked but never defined (see the help page).