Astronomy:Gliese 328
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| 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[1] mas/yr Dec.: −1045.876[1] mas/yr |
| Parallax (π) | 48.7404 ± 0.0184[1] mas |
| 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
- ↑ 1.0 1.1 1.2 1.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Pinamonti, M. 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.
- ↑ 3.0 3.1 "BD+02 2098". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=BD%2B02+2098.
- ↑ 4.0 4.1 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, doi:10.1051/0004-6361/201833173, Bibcode: 2019A&A...622A..40K
- ↑ 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, doi:10.1093/mnras/staa878, Bibcode: 2020MNRAS.494.2718W
- ↑ Ginski, C.; Mugrauer, M.; Seeliger, M.; Buder, S.; Errmann, R.; Avenhaus, H.; Mouillet, D.; Maire, A.-L. et al. (2016), "A lucky imaging multiplicity study of exoplanet host stars II", Monthly Notices of the Royal Astronomical Society 457 (2): 2173–2191, doi:10.1093/mnras/stw049, Bibcode: 2016MNRAS.457.2173G
- ↑ 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, doi:10.1088/0004-637X/774/2/147, Bibcode: 2013ApJ...774..147R
- ↑ 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, doi:10.1093/mnras/stz3408, Bibcode: 2020MNRAS.492..352K
Coordinates: 
08h 55m 07.6219s, +01° 32′ 47.4165″
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