HD 73534

HD 73534 / Gakyid
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cancer
Right ascension 08h 39m 15.803s[1]
Declination +12° 57′ 37.35″[1]
Apparent magnitude (V) 8.23[2]
Characteristics
Spectral type G5 IV[2]
Apparent magnitude (B) 9.192[3]
Apparent magnitude (J) 6.524±0.018[3]
Apparent magnitude (H) 6.072±0.020[3]
Apparent magnitude (K) 5.962±0.026[3]
B−V color index 0.962±0.021[3]
Astrometry
Radial velocity (Rv)+10.08±0.15[4] km/s
Proper motion (μ) RA: −114.147 mas/yr[1]
Dec.: −93.787 mas/yr[1]
Parallax (π)11.9576 ± 0.0254 mas[1]
Distance272.8 ± 0.6 ly
(83.6 ± 0.2 pc)
Absolute bolometric
magnitude (Mbol)		3.42[2]
Details[2]
Mass1.228±0.060 M☉
Radius2.39±0.16 R☉
Luminosity3.33±0.43 L☉
Surface gravity (log g)3.780±0.060 cgs
Temperature5,041±44 K
Metallicity [Fe/H]0.232±0.030 dex
Rotation~53 d
Rotational velocity (v sin i)< 1.0 km/s
Age7.1±0.8[5] Gyr
Other designations
Gakyid, BD+13°1956, HD 73534, HIP 42446, SAO 98004, PPM 125542[6]
Database references
SIMBADdata
Exoplanet Archivedata

HD 73534 is star with an orbiting exoplanet companion in the northern constellation of Cancer. With an apparent visual magnitude of 8.23,[2] it is too faint to be visible to the naked eye. The distance to this system is 273 light years based on parallax measurements,[1] and it is drifting further away with a heliocentric radial velocity of +10 km/s.[4]

The star HD 73534 has the proper name Gakyid. The name was selected by Bhutan during the 100th anniversary of the IAU as part of the IAU's NameExoWorlds project. Gakyid means happiness. The planet HD 73534 b is named Drukyul, which means 'land of the thunder dragon', the native name for Bhutan.[7][8]

This is a G-type subgiant star with a stellar classification of G5 IV. It has consumed the hydrogen at its core and begun to evolve off the main sequence, which is why it is much more luminous than the Sun. The star has a negligible level of magnetic activity in its chromosphere. It has 23% more mass than the Sun, and has expanded to 2.4 times the Sun's radius. The star is radiating 3.3 times the luminosity of the Sun from its photosphere at an effective temperature of 5,041 K.[2] It is roughly 7 billion[5] years old and is spinning slowly with a rotation period of around 53 days.[2]

In August 2009, it was announced that an exoplanet had been discovered using Doppler spectroscopy.[2] It is the first planetary system discovered in Cancer since that of 55 Cancri in April 1996, and the sixth planet, as 55 Cancri has five known planets.[citation needed]

The HD 73534 planetary system[9]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b ≥1.01±0.21 MJ 2.95±0.22 1721±36 0 (fixed) — —
  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 d e f g h Cite error: The named reference Valenti2009 was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Gaia DR2 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Bonfanti_et_al_2016 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference IAU was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference exoworld was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Ment2018 was invoked but never defined (see the help page).