HD 92945
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Hydra |
| Right ascension | 10h 43m 28.2717s[2] |
| Declination | −29° 03′ 51.421″[2] |
| Apparent magnitude (V) | 7.76[2] |
| Characteristics | |
| Spectral type | K1V[2] |
| B−V color index | 0.9[2] |
| Variable type | BY[3] |
| Astrometry | |
| Radial velocity (Rv) | 22.706±0.14[4] km/s |
| Proper motion (μ) | RA: −215.484[4] mas/yr Dec.: −49.892[4] mas/yr |
| Parallax (π) | 46.4931 ± 0.0198 mas[4] |
| Distance | 70.15 ± 0.03 ly (21.509 ± 0.009 pc) |
| Absolute magnitude (MV) | 6.07[5] |
| Details | |
| Mass | 0.80 (0.77 – 0.85)[6] M☉ |
| Radius | 0.77[7] R☉ |
| Luminosity | 0.38[7] L☉ |
| Temperature | 5000[6] K |
| Metallicity [Fe/H] | −0.17[6] dex |
| Rotational velocity (v sin i) | 4[6] km/s |
| Age | 294±23[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 92945 is a K-type main sequence star in the constellation of Hydra.[2] Its apparent visual magnitude varies by 0.02 magnitudes and is approximately 7.72 at maximum brightness.[3]
Debris disk
[edit]![Image of the debris disk with the REASONS survey[8]](/wiki/File:The_74_exocomet_belts_imaged_by_ALMA%E2%80%99s_REASONS_survey,_showing_belts_of_all_shapes,_sizes_and_ages_(REASONS_comboplot_full_nonames).jpg)
Image of the debris disk with the REASONS survey[8]
In 2007, a debris disk with estimated dust mass 0.047±0.003 ME[9] has been observed around the star by coronagraphic imaging, using the ACS and NICMOS instruments on the Hubble Space Telescope. It appears to extend 45 to 175 astronomical units from HD 92945.[10]
The disk has a gap at radius 73±3 AU which may be carved by the planet,[9] but no planet with mass exceeding 1-2 MJ was observed in the gap.[11]
Evidence for a planet via astrometric observations was presented in 2024.[12]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| Debris disk | 50–140 AU | 65.4±0.9° | — | |||
| (unconfirmed) | 0.7±0.3 MJ | 14±15 | — | — | — | — |
References
[edit]- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
- ^ a b c d e f g "V* V419 Hya". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved February 2, 2011.
- ^ a b V419 Hya, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars Archived 2017-06-20 at the Wayback Machine, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line February 2, 2011.
- ^ 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.
- ^ 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. S2CID 119257644.
- ^ a b c d HD 92945, database entry, The Geneva-Copenhagen Survey of Solar neighbourhood, J. Holmberg et al., 2007, CDS ID V/117A. Accessed on line February 2, 2011.
- ^ a b c Plavchan, Peter; et al. (June 2009). "New Debris Disks Around Young, Low-Mass Stars Discovered with the Spitzer Space Telescope". The Astrophysical Journal. 698 (2): 1068–1094. arXiv:0904.0819. Bibcode:2009ApJ...698.1068P. doi:10.1088/0004-637X/698/2/1068. S2CID 51417657.
- ^ Matrà, L.; Marino, S.; Wilner, D. J.; Kennedy, G. M.; Booth, M.; Krivov, A. V.; Williams, J. P.; Hughes, A. M.; Burgo, C. del (2025-01-15). "REsolved ALMA and SMA Observations of Nearby Stars (REASONS): A population of 74 resolved planetesimal belts at millimetre wavelengths". arXiv:2501.09058 [astro-ph].
- ^ a b c Marino, S.; Yelverton, B.; Booth, M.; Faramaz, V.; Kennedy, G. M.; Matrà, L.; Wyatt, M. C. (2019). "A gap in HD 92945's broad planetesimal disc revealed by ALMA". Monthly Notices of the Royal Astronomical Society. 484: 1257–1269. arXiv:1901.01406. doi:10.1093/mnras/stz049.
- ^ Golimowski, D.; John Krist, J.; Chen, C.; Stapelfeldt, K.; Ardila, D.; Clampin, M.; Schneider, G.; Silverstone, M.; Ford, H.; Illingworth, G. (2007). "Observations and Models of the Debris Disk around the K dwarf HD 92945". In the Spirit of Bernard Lyot: The Direct Detection of Planets and Circumstellar Disks in the 21st Century: 46. Bibcode:2007lyot.confE..46G.
- ^ Mesa, D.; et al. (2021). "Limits on the presence of planets in systems with debris discs: HD 92945 and HD 107146". Monthly Notices of the Royal Astronomical Society. 503: 1276–1289. arXiv:2102.05353. doi:10.1093/mnras/stab438.
- ^ a b Gratton, R.; Bonavita, M.; Mesa, D.; Desidera, S.; Zurlo, A.; Marino, S.; D’Orazi, V.; Rigliaco, E.; Nascimbeni, V.; Barbato, D.; Columba, G.; Squicciarini, V. (2024-05-01). "Stellar companions and Jupiter-like planets in young associations". Astronomy & Astrophysics. 685: A119. arXiv:2402.02148v1. doi:10.1051/0004-6361/202348393. ISSN 0004-6361.