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]
| 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] |
| Distance | 693 ± 4 ly (212 ± 1 pc) |
| Absolute magnitude (MV) | −0.46[1] |
| Details[5] | |
| Mass | 1.14±0.15 M☉ |
| Radius | 38.4±3.4 R☉ |
| Luminosity | 388.28±0.15 L☉ |
| Surface gravity (log g) | 1.1±0.2 cgs |
| Temperature | 3,940±40 K |
| Metallicity [Fe/H] | –0.16±0.14 dex |
| Rotational velocity (v sin i) | 4.5±0.1 km/s |
| Age | 6.8±2.7[3] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
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]
| 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 | — | — |
References
edit- ^ a b c d Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
- ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d e f Lee, Byeong-Cheol; et al. (July 2017). "Search for Exoplanets around Northern Circumpolar Stars. II. The Detection of Radial Velocity Variations in M Giant Stars HD 36384, HD 52030, and HD 208742". The Astrophysical Journal. 844 (1): 36. arXiv:1705.10009. Bibcode:2017ApJ...844...36L. doi:10.3847/1538-4357/aa7577. ISSN 0004-637X.
- ^ a b Famaey, B.; et al. (May 2009). "Spectroscopic binaries among Hipparcos M giants. I. Data, orbits, and intrinsic variations". Astronomy and Astrophysics. 498 (2): 627–640. arXiv:0901.0934. Bibcode:2009A&A...498..627F. doi:10.1051/0004-6361/200810698.
- ^ a b c Lee, Byeong-Cheol; et al. (August 2023). "A Search for Exoplanets around Northern Circumpolar Stars. VIII. Filtering Out a Planet Cycle from the Multi-Period Radial Velocity Variations in M Giant HD 36384". Journal of the Korean Astronomical Society. 56: 195–199. arXiv:2308.05994. Bibcode:2023JKAS...56..195L. doi:10.5303/JKAS.2023.56.2.195.
- ^ "HD 36384". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-12-15.
- ^ Gohd, Chelsea (August 31, 2023). "Discovery Alert: With Six New Worlds, 5,500 Discovery Milestone Passed!". Exoplanet Exploration: Planets Beyond our Solar System. Retrieved 2023-11-09.