HD 36384

HD 36384
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Camelopardalis[1]
Right ascension 05h 39m 43.707s[2]
Declination +75° 02′ 37.95″[2]
Apparent magnitude (V) 6.19[1]
Characteristics
Evolutionary stage Red giant
Spectral type M0 III[3]
B−V color index 1.606±0.006[1]
Variable type Suspected
Astrometry
Radial velocity (Rv)−4.97±0.11[4] km/s
Proper motion (μ) RA: −6.701 mas/yr[2]
Dec.: 26.589 mas/yr[2]
Parallax (π)4.7084 ± 0.0277 mas[2]
Distance693 ± 4 ly
(212 ± 1 pc)
Absolute magnitude (MV)−0.46[1]
Details[5]
Mass1.14±0.15 M
Radius38.4±3.4 R
Luminosity388.28±0.15 L
Surface gravity (log g)1.1±0.2 cgs
Temperature3,940±40 K
Metallicity [Fe/H]–0.16±0.14 dex
Rotational velocity (v sin i)4.5±0.1 km/s
Age6.8±2.7[3] Gyr
Other designations
NSV 2337, BD+74 252, HD 36384, HIP 26638, HR 1844, SAO 5593, PPM 6030[6]
Database references
SIMBADdata
Exoplanet Archivedata

HD 36384 is a star with an orbiting exoplanet companion in the northern constellation Camelopardalis. It is dimly visible to the naked eye with an apparent visual magnitude of 6.19.[3] The distance to this system is approximately 693 light-years based on parallax measurements, but is drifting closer with a heliocentric radial velocity of −5 km/s.[4]

This is an evolved red giant star with a stellar classification of M0 III.[3] It is a suspected variable star with a pulsation period of around 586 days. The star has 1.1 times the mass of the Sun and has expanded to 38.4 times the Sun's radius. It is radiating 388 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 3,940 K.[3]

In 2017, radial velocity variations were detected in this star, which were considered to most likely be caused by stellar pulsations.[3] A follow-up study by the same team in 2023 instead interpreted the radial velocity variations as being caused by a planetary companion, in addition to stellar activity. This is a super-jovian exoplanet with at least 6.6 times the mass of Jupiter; the exact mass is unknown since the orbital inclination has not been determined.[5] It was among the six exoplanet discoveries that marked the 5,500 discovery milestone.[7]

The HD 36384 planetary system[5]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b ≥ 6.6±0.5 MJ 1.3±0.1 490±3 0.2±0.1
  1. ^ a b c d Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  3. ^ a b c d e f Cite error: The named reference Lee_et_al_2017 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Famaey_et_al_2009 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Lee_et_al_2023 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 milestone was invoked but never defined (see the help page).