Star in the constellation Hydra
C Hydrae is a single[ 11] star in theequatorial constellation ofHydra ,[ 10] light years away from the Sun.[ 2] Flamsteed designation 30 Monocerotis ,[ 10] Monoceros . The object is visible to the naked eye as a white-hued star with anapparent visual magnitude of 3.90.[ 3] radial velocity of +10 km/s.[ 6]
This is anA-type main-sequence star with astellar classification of A0 Va.[ 5] [ 8] projected rotational velocity of 129 km/s. The star has 2.3 times themass of the Sun and about 2.5 times theSun's radius . It is radiating 37 times theluminosity of the Sun from itsphotosphere at aneffective temperature of 9,074 K.
Astatistically significant infrared excess has been detected, indicating adebris disk is orbiting± 0.1 AU blackbody temperature of± 3 Kasteroid belt .[ 12] X-ray emission has also been detected coming from these coordinates – stars of this class are not normally expected to show X-ray emission, so it may be coming from a background source or an unseen companion.[ 13]
^a b c 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 . XHIP record for this object atVizieR .^a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction",Astronomy and Astrophysics ,474 (2):653– 664,arXiv :0708.1752 Bibcode :2007A&A...474..653V ,doi :10.1051/0004-6361:20078357 ,S2CID 18759600 . ^a b Baines, Ellyn K.; et al. (2018), "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer",The Astronomical Journal ,155 (1), 30,arXiv :1712.08109 Bibcode :2018AJ....155...30B ,doi :10.3847/1538-3881/aa9d8b S2CID 119427037 . ^ Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities".Astronomy and Astrophysics .537 : A120.arXiv :1201.2052 Bibcode :2012A&A...537A.120Z .doi :10.1051/0004-6361/201117691 . ^a b Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample",The Astronomical Journal 132 (1):161– 170,arXiv :astro-ph/0603770 Bibcode :2006AJ....132..161G ,doi :10.1086/504637 ,S2CID 119476992 . ^a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project",Astronomy & Astrophysics ,546 : 14,arXiv :1208.3048 Bibcode :2012A&A...546A..61D ,doi :10.1051/0004-6361/201219219 ,S2CID 59451347 , A61. ^a b c d Hardegree-Ullman, Kevin K.; Apai, Dániel; Bergsten, Galen J.; Pascucci, Ilaria; López-Morales, Mercedes (2023), "Bioverse: A Comprehensive Assessment of the Capabilities of Extremely Large Telescopes to Probe Earth-like O2 Levels in Nearby Transiting Habitable-zone Exoplanets",The Astronomical Journal ,165 (6): 267,arXiv :2304.12490 Bibcode :2023AJ....165..267H ,doi :10.3847/1538-3881/acd1ec ^a b c d David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets",The Astrophysical Journal ,804 (2): 146,arXiv :1501.03154 Bibcode :2015ApJ...804..146D ,doi :10.1088/0004-637X/804/2/146 ,S2CID 33401607 . ^ Gáspár, András; Rieke, George H.; Ballering, Nicholas (2016), "The Correlation between Metallicity and Debris Disk Mass",The Astrophysical Journal ,826 (2): 171,arXiv :1604.07403 Bibcode :2016ApJ...826..171G ,doi :10.3847/0004-637X/826/2/171 ^a b c "30 Mon" ,SIMBAD Centre de données astronomiques de Strasbourg , retrievedMay 7, 2019 .^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems",Monthly Notices of the Royal Astronomical Society 389 (2):869– 879,arXiv :0806.2878 Bibcode :2008MNRAS.389..869E ,doi :10.1111/j.1365-2966.2008.13596.x S2CID 14878976 . ^ Moerchen, Margaret M.; et al. (November 2010), "High Spatial Resolution Imaging of Thermal Emission from Debris Disks",The Astrophysical Journal ,723 (2):1418– 1435,arXiv :1011.1410 Bibcode :2010ApJ...723.1418M ,doi :10.1088/0004-637X/723/2/1418 ,S2CID 118648798 . ^ Schröder, C.; Schmitt, J. H. M. M. (November 2007), "X-ray emission from A-type stars",Astronomy and Astrophysics ,475 (2):677– 684,Bibcode :2007A&A...475..677S ,doi :10.1051/0004-6361:20077429
