HIP30756 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD257498.
BD number is the number that the star was filed under in the Durchmusterung or Bonner Durchmusterung, a star catalogue that was put together by the Bonn Observatory between 1859 to 1903. The star's BD Number is BD+20 1426.
More details on objects' alternative names can be found at Star Names .
The location of the star in the night sky 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 object is compared to the celestial equator and is expressed in degrees. For HD 257498, the location is 06h 27m 45.94 and +20° 46` 59.6 .
HD 257498 has a spectral type of G0. This means the star is a white to yellow star. The star has a B-V Colour Index of 1.02 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,929 Kelvin.
Radius has been calculated as being 0.44 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 307,466.94.km. If you need the diameter of the star, you just need to multiple the radius by 2. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.
HD 257498 has an apparent magnitude of 8.59 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. Using the supplied Parallax value, you would get an absolute magnitude of 7.31 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 55.52 which gave the calculated distance to HD 257498 as 58.75 light years away from Earth or 18.01 parsecs. It would take a spaceship travelling at the speed of light, 58.75 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.
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.
|Primary / Proper / Traditional Name||HD 257498|
|Alternative Names||HD 257498, HIP 30756, BD+20 1426|
|Constellation's Main Star||No|
|Multiple Star System||Yes|
|Colour||White to Yellow|
|Visual / Apparent Magnitude||8.59|
|Naked Eye Visible||Requires a 7x50 Binoculars - Magnitudes|
|Right Ascension (R.A.)||06h 27m 45.94|
|Declination (Dec.)||+20° 46` 59.6|
|Galactic Latitude||4.36 degrees|
|Galactic Longitude||191.78 degrees|
|Distance from Earth||55.52 Parallax (milliarcseconds)|
|58.75 Light Years|
|3,714,803.28 Astronomical Units|
|Radius (x the Sun)||0.44|
|Effective Temperature||4,929 Kelvin|
The star has been identified as being a multi-star system, one in which there is at least one star in close orbit to another star or two or more stars orbiting a central point. The stars may be of equal mass, unequal mass where one star is stronger than the other or be in groups orbiting a central point which doesn't necessarily have to be a star. More information can be found on my dedicated multiple star systems page. The source of the info is Simbad. The file is dated 2000 so any differences between this and any other source will be down to the actual source from where the information came from.
|Proper Motion mas/yr|
|H.D. Id||B.D. Id||Star Code||Magnitude||R.A.||Dec.||Spectrum||Colour||Year|
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