Universe Guide


AG Pegasi, HD207757, HIP107848

AG Pegasi is a Wolf-Rayet star that can be located in the constellation of Pegasus. The star can not be seen by the naked eye, you need a telescope to see it.

HIP107848 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD207757.

AG Pegasi has alternative name(s), AG Peg.

Location of AG Pegasi

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 AG Pegasi, the location is 21h 51m 01.97 and +12d37`32.1 .

Physical Properties (Temperature, Radius) of AG Pegasi

AG Pegasi has a spectral type of WN6 + M3III. This means the star is a Wolf-Rayet star. The star has a B-V Colour Index of 1.15 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,576 Kelvin. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

AG Pegasi Apparent and Absolute Magnitudes

AG Pegasi has an apparent magnitude of 8.48 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 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 AG Pegasi

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as -0.30 which gave the calculated distance to AG Pegasi as -10872.11 light years away from Earth or -3333.33 parsecs. It would take a spaceship travelling at the speed of light, -10872.11 years to get there. We don't have the technology or spaceship that can carry people over that distance yet. AG Pegasi brightness ranges from a magnitude of 8.908 to a magnitude of 8.445 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.3 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.

AG Pegasi Facts

Alternative Names

Traditional/Proper NameAG Pegasi
Short NameAG Peg
Hipparcos Library I.D.107848
Bonner DurchmusterungBD+11 4673
Henry Draper Designation207757

Visual Facts

Star Type Wolf-Rayet star
Visual / Apparent Magnitude8.48
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)21h 51m 01.97
Declination (Dec.)+12d37`32.1
Galactic Latitude-30.89 degrees
Galactic Longitude69.28 degrees
1997 Distance from Earth-0.30 Parallax (milliarcseconds)
 -10872.11 Light Years
 -3333.33 Parsecs
B-V Index1.15
Radial Velocity-15.86 ± 0.15 km/s
Spectral TypeWN6 + M3III

Variable Star Details

Mean Variability Period in Days0.344
Variable Magnitude Range (Brighter - Dimmer)8.445 - 8.908

Estimated Facts

Calculated Effective Temperature4,576 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Add a Comment

Email: (Optional)