Astronomy:HD 156279

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Short description: Star in the constellation Draco
HD 156279
Observation data
Equinox J2000.0]] (ICRS)
Constellation Draco[1]
Right ascension  17h 12m 23.204816s[2]
Declination +63° 21′ 07.531205″[2]
Apparent magnitude (V) 8.167±0.013[3]
Characteristics
Evolutionary stage main-sequence[4]
Spectral type K0[3] or G6[4]
Apparent magnitude (R) 7.60[1]
Apparent magnitude (G) 7.8657[2]
Apparent magnitude (J) 6.677±0.018[1]
B−V color index 0.801±0.014[1]
Astrometry
Radial velocity (Rv)−20.144±0.161[5] km/s
Proper motion (μ) RA: −1.879±0.024[2] mas/yr
Dec.: 160.429±0.027[2] mas/yr
Parallax (π)27.6756 ± 0.0200[2] mas
Distance117.85 ± 0.09 ly
(36.13 ± 0.03 pc)
Absolute magnitude (MV)5.25[1]
Details
Mass0.93±0.02[6] M
Radius0.94±0.02[6] R
Luminosity0.70±0.01[6] L
Surface gravity (log g)4.45±0.03[6] cgs
Temperature5,449±31[6] K
Metallicity [Fe/H]0.14±0.01[3] dex
Rotational velocity (v sin i)2.51±1[4] km/s
Age7.4±2.2[6] Gyr
Other designations
BD+63 1335, Gaia DR2 1631084478574318976, HD 156279, HIP 84171, SAO 17390, PPM 20265, NLTT 44404, TYC 4202-656-1, 2MASS J17122319+6321074[7]
Database references
SIMBADdata

HD 156279 is a star with a pair of orbiting exoplanets[8] located in the northern constellation of Draco.[1] It has various alternate designations, including HIP 84171 and BD+63 1335. Parallax measurements yield a distance of 118 light years from the Sun,[2] but it is drifting closer with a radial velocity of −20 km/s.[5] Despite an absolute magnitude of 5.25,[1] at that distance the star is too faint to be visible to the naked eye with an apparent visual magnitude of 8.17.[3] It is presumed to be a single star, as in 2019 all imaging surveys have failed to find any stellar companions.[3]

The spectrum of HD 156279 has a stellar classification of G6[4] or K0,[3] depending on the study. Hence it presents as an ordinary main sequence star[4] of the late G-type or early K-type. The star has 93% of the mass of the Sun and 94% of the Sun's radius. HD 156279 is roughly seven[6] billion years old and is spinning with a projected rotational velocity of 2.5 km/s.[4] Based on the abundance of iron, this star is slightly enriched in heavy elements, having 140% of the solar abundance.[3] It is radiating 70%[6] of the luminosity of the Sun from its photosphere at an effective temperature of 5,449 K.[6]

Planetary system

Orbiting HD 156279 are two superjovian planets, the inner HD 156279 b (discovered in 2011)[4] and outer HD 156279 c (discovered in 2016).[8] In 2022, the inclination and true mass of HD 156279 c were measured via astrometry.[9]

The HD 156279 planetary system[10][9]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b ≥ 9.50+0.31
−0.32
 MJ
0.5041+0.0082
−0.0085
133.4031+0.0037
−0.0040
0.64779+0.00068
−0.00066
c 9.750+1.319
−0.605
 MJ
5.486+0.219
−0.240
4818.3+44.5
−43.1
0.261±0.006 74.699+36.999
−10.533
°

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Biller, B. et al. (2019), "A high binary fraction for the most massive close-in giant planets and brown dwarf desert members", Monthly Notices of the Royal Astronomical Society 485 (4): 4967–4996, doi:10.1093/mnras/stz671, Bibcode2019MNRAS.485.4967F. 
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Díaz, Rodrigo F. et al. (2012), "The SOPHIE search for northern extrasolar planets IV. Massive companions in the planet-brown dwarf boundary", Astronomy & Astrophysics A113: 538, doi:10.1051/0004-6361/201117935, Bibcode2012A&A...538A.113D. 
  5. 5.0 5.1 Carrera, R. et al. (February 2022), "OCCASO. IV. Radial velocities and open cluster kinematics", Astronomy & Astrophysics 658, doi:10.1051/0004-6361/202141832, A14, Bibcode2022A&A...658A..14C. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Bonfanti, A. et al. (2016), "Age consistency between exoplanet hosts and field stars", Astronomy & Astrophysics 585: 14, doi:10.1051/0004-6361/201527297, A5, Bibcode2016A&A...585A...5B. 
  7. "HD 156279". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+156279. 
  8. 8.0 8.1 Bryan, Marta L. et al. (2016), "Statistics of long period gas giant planets in known planetary systems", The Astrophysical Journal 821 (2): 89, doi:10.3847/0004-637X/821/2/89, Bibcode2016ApJ...821...89B. 
  9. 9.0 9.1 Feng, Fabo et al. (August 2022), "3D Selection of 167 Substellar Companions to Nearby Stars", The Astrophysical Journal Supplement Series 262 (21): 21, doi:10.3847/1538-4365/ac7e57, Bibcode2022ApJS..262...21F. 
  10. "HD 156279 Overview", NASA Exoplanet Archive (California Institute of Technology), https://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?objname=HD+156279&type=CONFIRMED_HOST, retrieved 2024-01-10.