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U Leporis, HD31599, HIP22952

U Leporis is a blue pulsating star that can be located in the constellation of Lepus. The star can not be seen by the naked eye, you need a telescope to see it.

HIP22952 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD31599.

U Leporis has alternative name(s), U Lep.

Location of U Leporis

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 U Leporis, the location is 04h 56m 17.96 and -21d 13` 01.5 .

Proper Motion of U Leporis

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 -59.59 ± 1.28 miliarcseconds/year towards the north and 41.45 ± 1.93 miliarcseconds/year east if we saw them in the horizon. The Radial Velocity, that is the speed at which the star is moving away/towards us is 120.00000 km/s with an error of about 2.50 km/s .

Physical Properties (Colour, Radius) of U Leporis

U Leporis has a spectral type of A9/F0Iab:. This means the star is a blue star. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures. The star's Iron Abundance is -1.78 with an error value of 9.99 Fe/H with the Sun has a value of 1 to put it into context.

U Leporis Apparent and Absolute Magnitudes

U Leporis has an apparent magnitude of 10.91 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 3.41 If you used the 2007 Parallax value, you would get an absolute magnitude of 2.07. 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 U Leporis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 3.16 which gave the calculated distance to U Leporis as 1032.16 light years away from Earth or 316.46 parsecs. It would take a spaceship travelling at the speed of light, 1032.16 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 1.71 which put U Leporis at a distance of 1907.39 light years or 584.80 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.

Variable Type of U Leporis

The star is a pulsating RR Lyrae type with asymmetric light curves 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. U Leporis brightness ranges from a magnitude of 11.163 to a magnitude of 9.851 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.6 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.

U Leporis Facts

Alternative Names

Traditional/Proper NameU Leporis
Short NameU Lep
Hipparcos Library I.D.22952
Bonner DurchmusterungBD-21 1019
Henry Draper Designation31599

Visual Facts

Star Type star
Absolute Magnitude3.41 / 2.07
Visual / Apparent Magnitude10.91
Naked Eye VisibleRequires a 4.5 - 6 Inch Telescope - Magnitudes
Right Ascension (R.A.)04h 56m 17.96
Declination (Dec.)-21d 13` 01.5
Galactic Latitude-34.37 degrees
Galactic Longitude221.11 degrees
1997 Distance from Earth3.16 Parallax (milliarcseconds)
 1032.16 Light Years
 316.46 Parsecs
2007 Revised Distance from Earth1.71 Parallax (milliarcseconds)
 1907.39 Light Years
 584.80 Parsecs
Proper Motion Dec.-59.59 ± 1.28 milliarcseconds/year
Proper Motion RA.41.45 ± 1.93 milliarcseconds/year
B-V Index-99.00
Radial Velocity120.00 ± 2.50 km/s
Iron Abundance-1.78 ± 9.99 Fe/H
Spectral TypeA9/F0Iab:
Colour(A) blue

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeRR Lyrae type with asymmetric light curves
Mean Variability Period in Days0.582
Variable Magnitude Range (Brighter - Dimmer)9.851 - 11.163

Sources and Links

SIMBAD SourceLink

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