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31 Crateris, 31 Corvi, HD104337, HIP58587, HR4590

31 Crateris is a blue pulsating star that can be located in the constellation of Corvus. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

The Id of the star in the Yale Bright Star Catalogue is HR4590. HIP58587 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD104337.

31 Crateris has alternative name(s), TY Crv.

Location of 31 Crateris

The location of the star in the galaxy is determined by the Right Ascension (R.A.) and Declination (Dec.), these are equivalent to the Longitude and Latitude on the Earth. The Right Ascension is how far expressed in time (hh:mm:ss) the star is along the celestial equator. If the R.A. is positive then its eastwards. The Declination is how far north or south the star is compared to the celestial equator and is expressed in degrees. For 31 Crateris, the location is 12h 00m 51.17 and -19d 39` 32.4 .

Proper Motion of 31 Crateris

All stars like planets orbit round a central spot, in the case of planets, its the central star such as the Sun. In the case of a star, its the galactic centre. The constellations that we see today will be different than they were 50,000 years ago or 50,000 years from now. Proper Motion details the movements of these stars and are measured in milliarcseconds. The star is moving 6.81 ± 0.28 miliarcseconds/year towards the north and -16.17 ± 0.53 miliarcseconds/year east if we saw them in the horizon. The Radial Velocity, that is the speed at which the star is moving away/towards us is 3.00000 km/s with an error of about 7.40 km/s .

Physical Properties (Colour, Temperature, Radius) of 31 Crateris

31 Crateris has a spectral type of B2IV. This means the star is a blue star. The star has a B-V Colour Index of -0.19 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 16,152 Kelvin.

31 Crateris Radius has been calculated as being 5.63 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 3,917,132.87.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 10.20. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

31 Crateris Apparent and Absolute Magnitudes

31 Crateris has an apparent magnitude of 5.28 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. If you used the 1997 Parallax value, you would get an absolute magnitude of -3.37 If you used the 2007 Parallax value, you would get an absolute magnitude of -4.66. Magnitude, whether it be apparent/visual or absolute magnitude is measured by a number, the smaller the number, the brighter the Star is. Our own Sun is the brightest star and therefore has the lowest of all magnitudes, -26.74. A faint star will have a high number.

Distance to 31 Crateris

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 1.86 which gave the calculated distance to 31 Crateris as 1753.57 light years away from Earth or 537.63 parsecs. It would take a spaceship travelling at the speed of light, 1753.57 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

In 2007, Hipparcos data was revised with a new parallax of 1.03 which put 31 Crateris at a distance of 3166.63 light years or 970.87 parsecs. It should not be taken as though the star is moving closer or further away from us. It is purely that the distance was recalculated.

Variable Type of 31 Crateris

The star is a pulsating Beta Cephei variable type which means that its size changes over time. The Variable Type is usually named after the first star of that type to be spotted. 31 Crateris brightness ranges from a magnitude of 5.230 to a magnitude of 5.189 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 1.5 days (variability).

Source of Information

The source of the information if it has a Hip I.D. is from Simbad, the Hipparcos data library based at the University at Strasbourg, France. Hipparcos was a E.S.A. satellite operation launched in 1989 for four years. The items in red are values that I've calculated so they could well be wrong. Information regarding Metallicity and/or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

31 Crateris Facts

Alternative Names

Traditional/Proper Name31 Crateris
Flamsteed Name31 Corvi
Flamsteed Short Name31 Crv
Short NameTY Crv
Hipparcos Library I.D.58587
Yale Bright Star Catalogue (HR) Id4590
Bonner DurchmusterungBD-18 3295
Henry Draper Designation104337

Visual Facts

Star Type star
Absolute Magnitude-3.37 / -4.66
Visual / Apparent Magnitude5.28
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)12h 00m 51.17
Declination (Dec.)-19d 39` 32.4
Galactic Latitude41.63 degrees
Galactic Longitude286.92 degrees
1997 Distance from Earth1.86 Parallax (milliarcseconds)
 1753.57 Light Years
 537.63 Parsecs
2007 Revised Distance from Earth1.03 Parallax (milliarcseconds)
 3166.63 Light Years
 970.87 Parsecs
Proper Motion Dec.6.81 ± 0.28 milliarcseconds/year
Proper Motion RA.-16.17 ± 0.53 milliarcseconds/year
B-V Index-0.19
Radial Velocity3.00 ± 7.40 km/s
Spectral TypeB2IV
Colour(B) blue

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeBeta Cephei
Mean Variability Period in Days1.482
Variable Magnitude Range (Brighter - Dimmer)5.189 - 5.230

Estimated Facts

Calculated Effective Temperature16,152 Kelvin

Sources and Links

SIMBAD SourceLink

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