Gliese 328
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]
Distance66.92 ± 0.03 ly
(20.517 ± 0.008 pc)
Details[2]
Mass0.65±0.08 M☉
Radius0.63±0.07 R☉
Luminosity0.08 L☉
Surface gravity (log g)4.64±0.07 cgs
Temperature3897±71 K
Metallicity [Fe/H]−0.06±0.09 dex
Rotation33.6 days[4]
Other designations
BD+02 2098, GJ 328, HIP 43790, Ross 623, TYC 213-177-1, 2MASS J08550761+0132472[3]
Database references
SIMBADdata

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]

The Gliese 328 planetary system[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. ^ 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.
  2. ^ 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.
  3. ^ a b "BD+02 2098". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-02-03.
  4. ^ 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
  5. ^ 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
  6. ^ 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
  7. ^ 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
  8. ^ 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


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