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BP Circini, HD129708, HIP72264

BP Circini is a blue to white pulsating luminous giant star that can be located in the constellation of Circinus. BP Circini is the brightest star in Circinus based on the Hipparcos 2007 apparent magnitude. The star can not be seen by the naked eye, you need a telescope to see it.

HIP72264 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD129708.

BP Circini has alternative name(s), BP Cir.

Location of BP Circini

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 BP Circini, the location is 14h 46m 41.99 and -61d27`43.0 .

Physical Properties (Colour, Temperature, Radius) of BP Circini

BP Circini has a spectral type of F2/F3II. This means the star is a blue to white luminous giant star. The star has a B-V Colour Index of 0.64 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,784 Kelvin.

BP Circini Radius has been calculated as being 224.14 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 155,954,927.38.km. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

BP Circini Apparent and Absolute Magnitudes

BP Circini has an apparent magnitude of 7.52 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 -6.91 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 BP Circini

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 0.13 which gave the calculated distance to BP Circini as 25089.49 light years away from Earth or 7692.31 parsecs. It would take a spaceship travelling at the speed of light, 25089.49 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

Variable Type of BP Circini

The star is a pulsating Cepheids 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. BP Circini brightness ranges from a magnitude of 7.840 to a magnitude of 7.504 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 2.4 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.

BP Circini Facts

Alternative Names

Traditional/Proper NameBP Circini
Short NameBP Cir
Hipparcos Library I.D.72264
Henry Draper Designation129708

Visual Facts

Star Typeluminous giant star
Visual / Apparent Magnitude7.52
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)14h 46m 41.99
Declination (Dec.)-61d27`43.0
Galactic Latitude-1.61 degrees
Galactic Longitude316.25 degrees
1997 Distance from Earth0.13 Parallax (milliarcseconds)
 25089.49 Light Years
 7692.31 Parsecs
B-V Index0.64
Radial Velocity-15.50 ± 2.50 km/s
Spectral TypeF2/F3II
Colour(F) blue to white

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeCepheids
Mean Variability Period in Days2.398
Variable Magnitude Range (Brighter - Dimmer)7.504 - 7.840

Estimated Facts

Calculated Effective Temperature5,784 Kelvin

Sources and Links

SIMBAD SourceLink

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