| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hydra |
| Right ascension | 08h 55m 07.62173s [1] |
| Declination | +01° 32′ 47.4151″ [1] |
| Apparent magnitude (V) | 9.997 [2] |
| Characteristics | |
| Evolutionary stage | main-sequence star |
| Spectral type | M0V [2] |
| B−V color index | 1.30 [2] |
| Astrometry | |
| Radial velocity (Rv) | −3.731±0.0015 [3] km/s |
| Proper motion (μ) |
RA: 44.944
mas/
yr
[1] Dec.: −1045.876 mas/ yr [1] |
| Parallax (π) | 48.7404 ± 0.0184 mas [1] |
| Distance | 66.92 ± 0.03
ly (20.517 ± 0.008 pc) |
| Details [2] | |
| Mass | 0.65±0.08 M☉ |
| Radius | 0.63±0.07 R☉ |
| Luminosity | 0.08 L☉ |
| Surface gravity (log g) | 4.64±0.07 cgs |
| Temperature | 3897±71 K |
| Metallicity [Fe/H] | −0.06±0.09 dex |
| Rotation | 33.6 days [4] |
| Other designations | |
| Database references | |
| SIMBAD | data |
Gliese 328, also known as BD+02 2098, is a M-type main-sequence star located 66.9 light-years (20.5 parsecs) away in the constellation Hydra. Its surface temperature is 3989 K. Gliese 328 is depleted in heavy elements compared to the Sun, with a metallicity Fe/H index of −0.13. [5] The age of the star is unknown. Gliese 328 exhibits an activity cycle similar to that of the Sun, with a period around 2000 d. [4]
Multiplicity surveys did not detect any stellar companions as of 2016. [6]
Planetary system
In 2013, one superjovian planet, named Gliese 328 b, was discovered on a wide, eccentric orbit by the radial velocity method. [7] The known planetary orbit is wide enough to not disrupt orbits of other bodies in the habitable zone of the star. [8] In 2023, a second, Neptune-mass planet was discovered orbiting closer to the star. [2]
| Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| c | ≥21.4+3.4 −3.2 M🜨 |
0.657+0.026 −0.028 |
241.8+1.3 −1.7 |
— | — | — |
| b | ≥2.51±0.23 MJ | 4.11+0.16 −0.18 |
3771±17 | 0.227±0.015 | — | — |
References
- ^ 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 Pinamonti, M.; Barbato, D.; et al. (June 2023). "The GAPS programme at TNG. XLVI. Deep search for low-mass planets in late-dwarf systems hosting cold Jupiters". Astronomy & Astrophysics. arXiv: 2306.04419. doi: 10.1051/0004-6361/202346476.
- ^ a b "BD+02 2098". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-02-03.
- ^ a b Küker, M.; Rüdiger, G.; Olah, K.; Strassmeier, K. G. (2019), "Cycle period, differential rotation and meridional flow for early M dwarf stars", Astronomy & Astrophysics, 622: A40, arXiv: 1804.02925, Bibcode: 2019A&A...622A..40K, doi: 10.1051/0004-6361/201833173, S2CID 118842388
- ^ Wallerstein, George; Woolf, Vincent M. (2020), "The M dwarf problem: Fe and Ti abundances in a volume-limited sample of M dwarf stars", Monthly Notices of the Royal Astronomical Society, 494 (2): 2718–2726, arXiv: 2003.11447, Bibcode: 2020MNRAS.494.2718W, doi: 10.1093/mnras/staa878, S2CID 214641078
- ^ Ginski, C.; Mugrauer, M.; Seeliger, M.; Buder, S.; Errmann, R.; Avenhaus, H.; Mouillet, D.; Maire, A.-L.; Raetz, S. (2016), "A lucky imaging multiplicity study of exoplanet host stars II", Monthly Notices of the Royal Astronomical Society, 457 (2): 2173–2191, arXiv: 1601.01524, Bibcode: 2016MNRAS.457.2173G, doi: 10.1093/mnras/stw049, S2CID 53626523
- ^ Robertson, Paul; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Boss, Alan P. (2013), "Secretly Eccentric: The Giant Planet and Activity Cycle of GJ 328", The Astrophysical Journal, 774 (2): 147, arXiv: 1307.7640, Bibcode: 2013ApJ...774..147R, doi: 10.1088/0004-637X/774/2/147, S2CID 118514735
- ^ Kokaia, Giorgi; Davies, Melvyn B.; Mustill, Alexander J. (2020), "Resilient habitability of nearby exoplanet systems", Monthly Notices of the Royal Astronomical Society, 492 (1): 352–368, arXiv: 1910.07573, Bibcode: 2020MNRAS.492..352K, doi: 10.1093/mnras/stz3408, S2CID 204743669