U Antliae is a carbon red pulsating star that can be located in the constellation of Antlia. 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 HR4153. HIP51821 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD91793.
U Antliae has alternative name(s), U Ant.
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 U Antliae, the location is 10h 35m 12.88 and -39d 33` 45.3 .
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 3.50 ± 0.39 miliarcseconds/year towards the north and -31.02 ± 0.54 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 41.00000 km/s with an error of about 4.40 km/s .
U Antliae has a spectral type of C. This means the star is a carbon red star. The star is 7377.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24061.0698868800000000s. The star has a B-V Colour Index of 3.01 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 0 Kelvin. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.
U Antliae has an apparent magnitude of 5.50 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 -1.54 If you used the 2007 Parallax value, you would get an absolute magnitude of -1.64. 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.
Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 3.90 which gave the calculated distance to U Antliae as 836.32 light years away from Earth or 256.41 parsecs. It would take a spaceship travelling at the speed of light, 836.32 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 3.73 which put U Antliae at a distance of 874.43 light years or 268.10 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 7,377.00 Parsecs or 24,061.07 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.
The star is a pulsating Slow 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. U Antliae brightness ranges from a magnitude of 5.699 to a magnitude of 5.261 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.4 days (variability).
|Traditional/Proper Name||U Antliae|
|Short Name||U Ant|
|Hipparcos Library I.D.||51821|
|Yale Bright Star Catalogue (HR) Id||4153|
|Henry Draper Designation||91793|
|Absolute Magnitude||-1.54 / -1.64|
|Visual / Apparent Magnitude||5.50|
|Naked Eye Visible||Yes - Magnitudes|
|Right Ascension (R.A.)||10h 35m 12.88|
|Declination (Dec.)||-39d 33` 45.3|
|Galactic Latitude||16.14 degrees|
|Galactic Longitude||276.22 degrees|
|1997 Distance from Earth||3.90 Parallax (milliarcseconds)|
|836.32 Light Years|
|2007 Revised Distance from Earth||3.73 Parallax (milliarcseconds)|
|874.43 Light Years|
|Galacto-Centric Distance||24,061.07 Light Years / 7,377.00 Parsecs|
|Proper Motion Dec.||3.50 ± 0.39 milliarcseconds/year|
|Proper Motion RA.||-31.02 ± 0.54 milliarcseconds/year|
|Radial Velocity||41.00 ± 4.40 km/s|
|Variable Star Class||Pulsating|
|Variable Star Type||Slow Irregular|
|Mean Variability Period in Days||0.419|
|Variable Magnitude Range (Brighter - Dimmer)||5.261 - 5.699|