Universe Guide

HomeFactsConstellationsAuriga

45 Aurigae, HD43905, HIP30247

45 Aurigae is a blue to white giant star that can be located in the constellation of Auriga. 45 Aurigae is the brightest star in Auriga based on the Hipparcos 2007 apparent magnitude. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it. The star has an estimated age of 1.10 Billion of Years but could be as young as 1.00 to 1.20 according to Hipparcos.

HIP30247 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD43905.

Location of 45 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 45 Aurigae, the location is 06h 21m 46.11 and +53d27`08.6 .

Proper Motion of 45 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 -88.69 ± 0.19 miliarcseconds/year towards the north and 21.98 ± 0.30 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Age, Radius) of 45 Aurigae

45 Aurigae has a spectral type of F5III.... This means the star is a blue to white giant star. The star is 7454.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24312.2156617600000000s. The star has a B-V Colour Index of 0.44 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 6,545 Kelvin.

45 Aurigae Radius has been calculated as being 3.54 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 2,463,503.67.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 3.67. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures. The star's Iron Abundance is 0.23 with an error value of 0.03 Fe/H with the Sun has a value of 1 to put it into context.

The stars age according to Hipparcos data files put the star at an age of about 1.10 Billion years old but could be between 1.00 and 1.20 Billion years old. In comparison, the Sun's age is about 4.6 Billion Years Old.

45 Aurigae Apparent and Absolute Magnitudes

45 Aurigae has an apparent magnitude of 5.34 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 1.56 If you used the 2007 Parallax value, you would get an absolute magnitude of 1.48. 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 45 Aurigae

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 17.54 which gave the calculated distance to 45 Aurigae as 185.95 light years away from Earth or 57.01 parsecs. It would take a spaceship travelling at the speed of light, 185.95 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 16.89 which put 45 Aurigae at a distance of 193.11 light years or 59.21 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.

The star's Galacto-Centric Distance is 7,454.00 Parsecs or 24,312.22 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

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.

45 Aurigae Facts

Alternative Names

Traditional/Proper Name45 Aurigae
Flamsteed Name45 Aurigae
Flamsteed Short Name45 Aur
Hipparcos Library I.D.30247
Bonner DurchmusterungBD+53 1008
Henry Draper Designation43905

Visual Facts

Star Typegiant star
Age1.10 Billion Years Old
Age Range1.00 - 1.20 Billion Years Old
Absolute Magnitude1.56 / 1.48
Visual / Apparent Magnitude5.34
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)06h 21m 46.11
Declination (Dec.)+53d27`08.6
Galactic Latitude17.33 degrees
Galactic Longitude161.15 degrees
1997 Distance from Earth17.54 Parallax (milliarcseconds)
 185.95 Light Years
 57.01 Parsecs
2007 Revised Distance from Earth16.89 Parallax (milliarcseconds)
 193.11 Light Years
 59.21 Parsecs
Galacto-Centric Distance24,312.22 Light Years / 7,454.00 Parsecs
Proper Motion Dec.-88.69 ± 0.19 milliarcseconds/year
Proper Motion RA.21.98 ± 0.30 milliarcseconds/year
B-V Index0.44
Radial Velocity-0.40 ± 0.10 km/s
Iron Abundance0.23 ± 0.03 Fe/H
Spectral TypeF5III...
Colour(F) blue to white

Estimated Facts

Calculated Effective Temperature6,545 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars


Add a Comment


Name:
Email: (Optional)
Comment: