Astronomy:HD 92945
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Short description: Star in the constellation Hydra
| Observation data 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[4] mas |
| 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
![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 M⊕[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
- ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 "V* V419 Hya". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=V%2A+V419+Hya.
- ↑ 3.0 3.1 V419 Hya, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars , Sternberg Astronomical Institute, Moscow, Russia. Accessed on line February 2, 2011.
- ↑ 4.0 4.1 4.2 4.3 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.
- ↑ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 6.0 6.1 6.2 6.3 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.
- ↑ 7.0 7.1 7.2 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. doi:10.1088/0004-637X/698/2/1068. Bibcode: 2009ApJ...698.1068P.
- ↑ Matrà, L.; Marino, S.; Wilner, D. J.; Kennedy, G. M.; Booth, M.; Krivov, A. V.; Williams, J. P.; Hughes, A. M. et al. (2025-01-15). "REsolved ALMA and SMA Observations of Nearby Stars (REASONS): A population of 74 resolved planetesimal belts at millimetre wavelengths". Astronomy and Astrophysics 693. doi:10.1051/0004-6361/202451397. Bibcode: 2025A&A...693A.151M.
- ↑ 9.0 9.1 9.2 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. doi:10.1093/mnras/stz049.
- ↑ Golimowski, D.; John Krist, J.; Chen, C.; Stapelfeldt, K.; Ardila, D.; Clampin, M.; Schneider, G.; Silverstone, M. et al. (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. doi:10.1093/mnras/stab438.
- ↑ 12.0 12.1 Gratton, R.; Bonavita, M.; Mesa, D.; Desidera, S.; Zurlo, A.; Marino, S.; D’Orazi, V.; Rigliaco, E. et al. (2024-05-01). "Stellar companions and Jupiter-like planets in young associations" (in en). Astronomy & Astrophysics 685: A119. doi:10.1051/0004-6361/202348393. ISSN 0004-6361.
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