GJ 2030
| 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 |
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]
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
[edit]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° |
— |
References
[edit]- ^ a b 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. XHIP record for this object at VizieR.
- ^ a b c d e f g h 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 Paunzen, E. (August 2015). "A new catalogue of Strömgren-Crawford uvbyβ photometry". Astronomy and Astrophysics. 580: A23. arXiv:1506.04568. Bibcode:2015A&A...580A..23P. doi:10.1051/0004-6361/201526413. ISSN 0004-6361.
- ^ a b Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars, Vol. 5". Michigan Spectral Survey. 5: 0. Bibcode:1999MSS...C05....0H.
- ^ a b c Soubiran, C.; et al. (2024-02-01). "Gaia FGK benchmark stars: Fundamental Teff and log g of the third version". Astronomy and Astrophysics. 682: A145. arXiv:2310.11302. Bibcode:2024A&A...682A.145S. doi:10.1051/0004-6361/202347136. ISSN 0004-6361.
- ^ a b Casagrande, L.; Schönrich, R.; Asplund, M.; Cassisi, S.; Ramírez, I.; Meléndez, J.; Bensby, T.; Feltzing, S. (June 2011). "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey". Astronomy and Astrophysics. 530: A138. arXiv:1103.4651. Bibcode:2011A&A...530A.138C. doi:10.1051/0004-6361/201016276. ISSN 0004-6361.
- ^ "GJ 2030". SIMBAD. Centre de données astronomiques de Strasbourg.
- ^ "Limiting Magnitude | COSMOS". astronomy.swin.edu.au. Retrieved 2025-06-01.
- ^ "The Colour of Stars". Australia Telescope, Outreach and Education. Commonwealth Scientific and Industrial Research Organisation. December 21, 2004. Archived from the original on 2013-12-03. Retrieved 2012-01-16.
- ^ Horch, Elliott P.; van Belle, Gerard T.; Davidson, James W.; Ciastko, Lindsay A.; Everett, Mark E.; Bjorkman, Karen S. (November 2015). "Observations of Binary Stars with the Differential Speckle Survey Instrument. VI. Measures during 2014 at the Discovery Channel Telescope". The Astronomical Journal. 150 (5): 151. arXiv:1509.03498. Bibcode:2015AJ....150..151H. doi:10.1088/0004-6256/150/5/151. ISSN 0004-6256.
- ^ a b Feng, Fabo; Butler, R. Paul; et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series. 262 (21): 21. arXiv:2208.12720. Bibcode:2022ApJS..262...21F. doi:10.3847/1538-4365/ac7e57. S2CID 251864022.
