GJ 2030
Star in the constellation Eridanus
From Wikipedia, the free encyclopedia
GJ 2030 is a star in the constellation Eridanus. At an apparent magnitude of +6.206,[3] it is close to the average threshold for naked eye visibility, and can only be viewed from sufficiently dark skies, far from light pollution.[8] Parallax measurements by the Gaia spacecraft measured a distance of 121.7 light-years, give or take 0.4 light-years.[2]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Eridanus[1] |
| Right ascension | 03h 23m 17.70116s[2] |
| Declination | −07° 47′ 38.7554″[2] |
| Apparent magnitude (V) | 6.206±0.003[3] |
| Characteristics | |
| Evolutionary stage | subgiant[2] |
| Spectral type | G5/6V[4] |
| Astrometry | |
| Radial velocity (Rv) | +41.67±0.16[2] km/s |
| Proper motion (μ) | RA: +1.295 mas/yr[2] Dec.: −219.292 mas/yr[2] |
| Parallax (π) | 26.7913±0.0912 mas[2] |
| Distance | 121.7 ± 0.4 ly (37.3 ± 0.1 pc) |
| Absolute magnitude (MV) | +3.35[1] |
| Details[5] | |
| Mass | 1.022±0.024 M☉ |
| Radius | 2.429±0.061 R☉ |
| Luminosity | 4.064±0.043 L☉ |
| Surface gravity (log g) | 3.73±0.12 cgs |
| Temperature | 5,259±66 K |
| Metallicity [Fe/H] | −0.45±0.02 dex |
| Age | 6.39[6] Gyr |
| Other designations | |
| BD−08°643, GJ 2030, HD 21019, HIP 15776, HR 1024, TYC 5295-1155-1[7] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
The spectrum of this star matches a spectral class of G5/6V,[4] with the luminosity class V suggesting it is a main sequence star, but its physical properties suggest it is actually a subgiant.[2] It has 1.02 times the Sun's mass and 2.43 times the Sun's radius. It radiates 4.06 times the Sun's luminosity from its photosphere at an effective temperature of 5,259 K.[5] At this temperature, the star shines with a yellowish color typical of G-type stars.[9]
GJ 2030 is likely a member of the thick disk population,[10] with a substantially lower metallicity than the Sun.[5] Its age is estimated at 6.39 billion years, older than the Solar System.[6]
Planetary system
Two extrasolar planets were discovered around the star in 2022, detected via Doppler spectroscopy (radial velocity method) and astrometry.[11]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥0.015±0.002 MJ | 0.034+0.001 −0.002 |
0.0065196±0.0000004 | 0.239+0.075 −0.058 |
— | — |
| c | 12.803+2.335 −2.136 MJ |
16.761+1.294 −1.337 |
69.91+6.36 −7.00 |
0.041+0.003 −0.008 |
16.999+2.935 −2.535° |
— |