HD 120084
HD 120084 is a star in the constellation of Ursa Minor. With an apparent magnitude of 5.91,[2] it is just visible to the naked eye in suburban skies.[4]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Ursa Minor |
| Right ascension | 13h 42m 39.2026s[1] |
| Declination | +78° 03′ 51.9793″[1] |
| Apparent magnitude (V) | 5.91[2] |
| Characteristics | |
| Spectral type | G7III[2] |
| B−V color index | 1.000[2] |
| Astrometry | |
| Proper motion (μ) | RA: −65.088±0.098[1] mas/yr Dec.: 46.199±0.083[1] mas/yr |
| Parallax (π) | 9.6760 ± 0.0484[1] mas |
| Distance | 337 ± 2 ly (103.3 ± 0.5 pc) |
| Absolute magnitude (MV) | +0.96[2] |
| Details[2] | |
| Mass | 2.39 (2.09–2.45) M☉ |
| Radius | 9.12 (8.51–9.77) R☉ |
| Luminosity | 43.7 L☉ |
| Surface gravity (log g) | 2.71±0.08 cgs |
| Temperature | 4892±22 K |
| Metallicity [Fe/H] | +0.09±0.05 dex |
| Rotational velocity (v sin i) | 2.44 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
It is a yellow giant of spectral type G7III and surface temperature of around 4892 K, around 2.4 times the mass, 43 times the luminosity and 9 times the radius of our Sun. There is one planet known to orbit this star.[2]
Planetary system
A planet with at least 4.5 times the mass of Jupiter and a highly eccentric orbit (with an eccentricity of 0.66) was discovered by precisely measuring the radial velocity of the star in 2013. With an average distance of 4.5 AU from its star, this planet has one of the most eccentric orbits discovered.[2]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥4.5 MJ | 4.3 | 2082+24 −35 |
0.66+0.14 −0.10 |
— | — |
References
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- Sato, Bun’ei; et al. (2013). "Planetary Companions to Three Evolved Intermediate-Mass Stars: HD 2952, HD 120084, and ω Serpentis". Publications of the Astronomical Society of Japan. 65 (4). 85. arXiv:1304.4328. Bibcode:2013PASJ...65...85S. doi:10.1093/pasj/65.4.85.
- "HD 120084". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-10-07.
- Bortle, John E. (February 2001). "The Bortle Dark-Sky Scale". Sky & Telescope. Sky Publishing Corporation. Retrieved 2013-02-20.
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