Universe Guide

140 G. Oph - HD157955 - HIP85442

140 G. Oph is a blue subgiant star that can be located in the constellation of Ophiuchus. HIP85442 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD157955. The Id of the star in the Gould Star Catalogue is 140. Stars in the southern hemisphere are more likely to have a Gould Id than the northern hemisphere. For example, there are no Gould classified stars in Ursa Major.

Location of 140 G. Oph

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 from celestial equator. The Declination is how up or down compared to the celestial equator and is expressed in degrees. For 140 G. Oph, the location is 17h 27m 37.56 and -29 d 43`28.2 .

Proper Motion of 140 G. Oph

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 -032.00 ± 000.00 towards the north and -005.00 ± 000.00 east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of 140 G. Oph

140 G. Oph has a spectral type of B9.5IV. This means the star is a blue coloured subgiant star. The star has a B-V Colour Index of 0.01 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 9,392 Kelvin.

140 G. Oph has been calculated as 4.50 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 3,132,397.48.km.

140 G. Oph Apparent and Absolute Magnitudes

140 G. Oph has an apparent magnitude of 5.98 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 -0.53 If you used the 2007 Parallax value, you would get an absolute magnitude of -1.01. 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 140 G. Oph

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 5.00 which gave the calculated distance to 140 G. Oph as 652.33 light years away from us or 200 parsecs. In 2007, Hipparcos data was revised with a new parallax of 4.00 which put 140 G. Oph at a distance of 815.41 light years or 250 parsecs.

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 Stellar Age, Metallicity or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

140 G. Oph Facts


Traditional Name140 G. Oph
Hipparcos Library I.D.85442
Gould I.D.140
Henry Draper Designation157955
Celestial TypeStar
Absolute Magnitude-0.53 / -1.01
Apparent Magnitude5.98
Right Ascension (R.A.)17h 27m 37.56
Declination (Dec.)-29 d 43`28.2
1997 Distance5.00 Parallax (milliarcseconds)
 652.33 Light Years
 200 Parsecs
2007 Distance4.00 Parallax (milliarcseconds)
 815.41 Light Years
 250 Parsecs
Proper Motion Dec.-32.00 ± 0.00 milliarcseconds/year
Proper Motion RA.-5.00 ± 0.00 milliarcseconds/year
B-V Index0.01
Spectral TypeB9.5IV
Colour(B) blue
Star Typesubgiant star
Radius (x the Sun)4.50
Calculated Effective Temperature9,392 Kelvin


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