C Hydrae

C Hydrae
Observation data
Epoch J2000      Equinox J2000
Constellation Hydra
Right ascension 08h 25m 39.63201s[1]
Declination −03° 54′ 23.1178″[1]
Apparent magnitude (V) 3.90[2]
Characteristics
Spectral type A0 Va[3]
B−V color index −0.012±0.003[4]
Astrometry
Radial velocity (Rv)+10.00±1.78[5] km/s
Proper motion (μ) RA: −66.43[1] mas/yr
Dec.: −23.41[1] mas/yr
Parallax (π)26.66 ± 0.19 mas[1]
Distance122.3 ± 0.9 ly
(37.5 ± 0.3 pc)
Absolute magnitude (MV)1.04[4]
Details
Mass2.36[6] M☉
Radius2.7[7] R☉
Luminosity40.05[4] L☉
Surface gravity (log g)4.20[6] cgs
Temperature10,281±350[6] K
Rotational velocity (v sin i)129[6] km/s
Age162[6] Myr
Other designations
C Hya, 30 Mon, BD−03°2339, HD 71155, HIP 41307, HR 3314, SAO 135896[8]
Database references
SIMBADdata

30 Monocerotis is a single[9] star in the equatorial constellation of Hydra,[8] located 122 light years away from the Sun.[1] It has the Bayer designation C Hydrae;[8] 30 Monocerotis is the Flamsteed designation and was assigned when it belonged to the constellation Monoceros. The object is visible to the naked eye as a white-hued star with an apparent visual magnitude of 3.90.[2] It is moving away from the Earth with a heliocentric radial velocity of +10 km/s.[5]

This is an A-type main-sequence star with a stellar classification of A0 Va.[3] It is around 162[6] million years old with a high rate of spin, showing a projected rotational velocity of 129 km/s.[6] The star has 2.36[6] times the mass of the Sun and about 2.7[7] times the Sun's radius. It is radiating 40[4] times the luminosity of the Sun from its photosphere at an effective temperature of 10,281 K.[6]

A statistically significant infrared excess has been detected, indicating a debris disk is orbiting 2.0±0.1 AU from the host star with a blackbody temperature of 499±3 K. It is comparable in size to the asteroid belt.[10] An unexplained 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.[11]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Baines2018 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Gray2006 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  6. ^ a b c d e f g h i Cite error: The named reference David2015 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference PasinettiFracassini2001 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Moerchen2010 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Schroeder2007 was invoked but never defined (see the help page).