Universe Guide


AB Aurigae - HD31293 - HIP22910

AB Aurigae is a blue eruptive star that can be located in the constellation of Auriga. HIP22910 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD31293. AB Aurigae has alternative name(s), AB_Aur.

Location of AB Aurigae

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 AB Aurigae, the location is 04h 55m 45.84 and +30d33`04.5 .

Proper Motion of AB Aurigae

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 -024.73 ± 000.55 towards the north and 002.63 ± 000.96 east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of AB Aurigae

AB Aurigae has a spectral type of A0pe. This means the star is a blue star. The star has a B-V Colour Index of 0.13 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 8,061 Kelvin.

AB Aurigae has been calculated as 2.72 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,890,592.42.km.

AB Aurigae Apparent and Absolute Magnitudes

AB Aurigae has an apparent magnitude of 7.03 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 1.23 If you used the 2007 Parallax value, you would get an absolute magnitude of 1.31. 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 AB Aurigae

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 6.93 which gave the calculated distance to AB Aurigae as 470.65 light years away from Earth or 144.30 parsecs. It would take a spaceship travelling at the speed of light, 470.65 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 7.18 which put AB Aurigae at a distance of 454.27 light years or 139.28 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 AB Aurigae

The star is a eruptive Irregular 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. AB Aurigae brightness ranges from a magnitude of 7.000 to a magnitude of 7.000 over its variable period. The smaller the magnitude, the brighter the star.

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 Stellar Age, Metallicity or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

AB Aurigae Facts

Alternative Names

Traditional NameAB Aurigae
Short NameAB Aur
Hipparcos Library I.D.22910
Bonner DurchmusterungBD+30 741
Henry Draper Designation31293

Visual Facts

Star Type star
Absolute Magnitude1.23 / 1.31
Apparent Magnitude7.03
Right Ascension (R.A.)04h 55m 45.84
Declination (Dec.)+30d33`04.5
1997 Distance from Earth6.93 Parallax (milliarcseconds)
 470.65 Light Years
 144.30 Parsecs
2007 Revised Distance from Earth7.18 Parallax (milliarcseconds)
 454.27 Light Years
 139.28 Parsecs
Proper Motion Dec.-24.73 ± 0.55 milliarcseconds/year
Proper Motion RA.2.63 ± 0.96 milliarcseconds/year
B-V Index0.13
Spectral TypeA0pe
Colour(A) blue

Variable Star Details

Variable Star ClassEruptive
Variable Star TypeIrregular

Estimated Facts

Radius (x the Sun)2.72
Calculated Effective Temperature8,061 Kelvin

Sources and Links

SIMBAD SourceLink

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