V399 Lacertae is a blue very luminous supergiant star that can be located in the constellation of Lacerta. HIP109205 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD210221. V399 Lacertae has alternative name(s), V399_Lac.
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 V399 Lacertae, the location is 22h 07m 25.59 and +53 d 18`26.8 .
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 -003.08 ± 000.19 towards the north and -003.02 ± 000.27 east if we saw them in the horizon.
V399 Lacertae has a spectral type of A3Ib. This means the star is a blue supergiant star. The star has a B-V Colour Index of 0.38 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 6,465 Kelvin.
V399 Lacertae has an apparent magnitude of 6.17 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 If you used the 2007 Parallax value, you would get an absolute magnitude of -5.42. 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 -1.00 which gave the calculated distance to V399 Lacertae as -3261.63 light years away from Earth or -1000 parsecs. It would take a spaceship travelling at the speed of light, -3261.63 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 0.48 which put V399 Lacertae at a distance of 6795.07 light years or 2083.33 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. V399 Lacertae brightness ranges from a magnitude of 6.000 to a magnitude of 6.000 over its variable period. The smaller the magnitude, the brighter the star.
|Traditional Name||V399 Lacertae|
|Short Name||V399 Lac|
|Hipparcos Library I.D.||109205|
|Bonner Durchmusterung||BD+52 3114|
|Henry Draper Designation||210221|
|Star Type||supergiant star|
|Right Ascension (R.A.)||22h 07m 25.59|
|Declination (Dec.)||+53 d 18`26.8|
|1997 Distance from Earth||-1.00 Parallax (milliarcseconds)|
|-3261.63 Light Years|
|2007 Revised Distance from Earth||0.48 Parallax (milliarcseconds)|
|6795.07 Light Years|
|Proper Motion Dec.||-3.08 ± 0.19 milliarcseconds/year|
|Proper Motion RA.||-3.02 ± 0.27 milliarcseconds/year|
|Calculated Effective Temperature||6,465 Kelvin|