HD 139357

HD 139357
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Draco
Right ascension 15h 35m 16.198593s[1]
Declination +53° 55′ 19.709392″[1]
Apparent magnitude (V) 5.97[2]
Characteristics
Spectral type K4III[3]
B−V color index 1.184±0.006[2]
Astrometry
Radial velocity (Rv)−8.53±0.13[1] km/s
Proper motion (μ) RA: −18.845±0.051 mas/yr[1]
Dec.: 2.097±0.063 mas/yr[1]
Parallax (π)8.8114 ± 0.0460 mas[1]
Distance370 ± 2 ly
(113.5 ± 0.6 pc)
Absolute magnitude (MV)0.61[2]
Details
Mass1.1±0.1 M☉[4]
1.35±0.24 M☉[5]
2.16±0.18[3] M☉
Radius11.47±0.75 R☉[5]
14.4±0.4[3] R☉
Luminosity74±1[4] L☉
Surface gravity (log g)2.2±0.1 cgs[4]
2.63±0.10 cgs[6]
2.9±0.15[5] cgs
Temperature4,601±28[6] K
Metallicity [Fe/H]−0.13±0.05 dex[5]
0.34±0.05[3] dex
Age1.19±0.33 Gyr[6]
3.07±1.47 Gyr[3]
7.20±1.80[4] Gyr
Other designations
BD+54°1756, GC 20977, HD 139357, HIP 76311, HR 5811, SAO 29583, PPM 35043, GCRV 9003[7]
Database references
SIMBADdata
Exoplanet Archivedata

HD 139357 is a 6th magnitude K-type giant star located approximately 370 light years from Earth, visible in the constellation Draco. Its mass is four thirds that of the Sun but its radius is 11.47 times larger. However, despite being a giant star, it is only 3.07 billion years old, which is younger than the Sun.

It hosts a substellar companion with a minimum mass of 9.76 MJ, discovered in 2009.[5] A 2022 study estimated the true mass of HD 139357 b at about 16.38 MJ via astrometry, although this estimate is poorly constrained. If this is the true mass, the object would be a brown dwarf.[8]

The HD 139357 planetary system[5]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b ≥9.76 ± 2.15 MJ 2.36 ± 0.02 1125.7 ± 9 0.10 ± 0.02 — —
  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference Maldonado_et_al_2019 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Bonfanti_et_al_2016 was invoked but never defined (see the help page).
  5. ^ a b c d e f Cite error: The named reference Döllinger_et_al_2009 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Maldonado_Villaver_2016 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 Feng2022 was invoked but never defined (see the help page).