31 crateris

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Double star
31 Crateris
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation Crow
Right ascension 12 h 00 m 51.16 s
declination −19 ° 32 ′ 32.6 ″
Apparent brightness (5.26 ± 0.01) mag
Typing
B − V color index −0.18 
Spectral class B2 IV
Variable star type ELL 
Astrometry
Radial velocity 1.7 ± 2 km / s
parallax (2.05 ± 0.24)  mas
distance (1,600)  ly
(500)  pc
Proper movement 
Rec. Share: (−17.68 ± 0.36)  mas / a
Dec. portion: (6.46 ± 0.20)  mas / a
Physical Properties
Dimensions 15.5  M ☉
Luminosity

52000  L ☉

Effective temperature 23700  K
Other names
and catalog entries
Flamsteed name 31 crateris
Bonn survey BD −18 ° 3295
Bright Star Catalog HR 4590 [1]
Henry Draper Catalog HD 104337 [2]
Hipparcos catalog HIP 58587 [3]
SAO catalog SAO 157042 [4]
Tycho catalog TYC 6097-1648-1 [5]
2MASS catalog 2MASS J12005117-193932 [6]
Other names TV Corvi, FK5 2961

31 Crateris is a binary star system in the raven constellation . Alternating between the apparent magnitudes 5.19 and 5.23 over 1.48 days, it has the name of a variable star called TY Corvi . It is actually a system with a blue and white star belonging to the spectral class B1.5V and a companion that little is known about. The two stars orbit each other every 2.9631 days. The main star is possibly a blue straggler of the Hyades . It is 15.5 times more massive than the sun and 52,000 times brighter than the sun.

The British astronomer John Flamsteed numbered the stars in an expanded constellation called Hydra and Crater in a publication from 1712 , which includes the stars just below the constellation of Hydra . Later astronomers did not follow him in this. 31 Crateris ultimately got into the raven constellation after formal borders were drawn in 1922.

31 Crateris could be an orbiting binary star

On March 27, 1974, the Mariner 10 mission detected emissions in the far ultraviolet. At first it was thought to be a moon from Mercury until 31 Crateris was identified as the source.

Individual evidence

  1. ↑ a b c d e f 31 Crt. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed September 15, 2019 .
  2. ↑ a b c TY Crv. In: VSX. AAVSO , accessed September 15, 2019 .
  3. ↑ a b c d adsabs.harvard.edu
  4. ↑ adsabs.harvard.edu
  5. ↑ Morton Wagman: Lost Stars: Lost, Missing and Troublesome Stars from the Catalogs of Johannes Bayer, Nicholas Louis de Lacaille, John Flamsteed, and Sundry Others . The McDonald & Woodward Publishing Company, Blacksburg, Virginia 2003, ISBN 0-939923-78-5 , pp. 390-391 .
  6. ↑ a b R. L. Stratford: 31 Crateris reexamined . In: The Observatory . tape 100 , 1980, pp. 168 , bibcode : 1980Obs ... 100..168S .
  7. ^ Patrick Moore: The Data Book of Astronomy . CRC Press , 2000, ISBN 1-4200-3344-1 , pp. 79 ( com.au ).