Universe Guide
AliensAliensConstellationsTelevision and Films ListFact ListGames ListWarcraftSearchTwitterFacebook


R Lyrae, 13 Lyrae, HD175865, HIP92862, HR7157

R Lyrae is a red pulsating star that can be located in the constellation of Lyra. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

The Id of the star in the Yale Bright Star Catalogue is HR7157. HIP92862 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD175865.

R Lyrae has alternative name(s), R Lyr.

Location of R Lyrae

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 R Lyrae, the location is 18h 55m 20.09 and +43d 56` 45.2 .

Proper Motion of R Lyrae

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 82.06 ± 0.11 miliarcseconds/year towards the north and 21.05 ± 0.12 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 -27.15000 km/s with an error of about 0.20 km/s .

Physical Properties (Colour, Temperature, Radius) of R Lyrae

R Lyrae has a spectral type of M5IIIvar. This means the star is a red star. The star is 7376.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24057.8082534400000000s. The star has a B-V Colour Index of 1.39 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,176 Kelvin.

R Lyrae Radius has been calculated as being 29.20 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 20,317,831.53.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 24.85. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

R Lyrae Apparent and Absolute Magnitudes

R Lyrae has an apparent magnitude of 4.08 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 -1.07 If you used the 2007 Parallax value, you would get an absolute magnitude of -0.72. 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 R Lyrae

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 9.33 which gave the calculated distance to R Lyrae as 349.59 light years away from Earth or 107.18 parsecs. It would take a spaceship travelling at the speed of light, 349.59 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 10.94 which put R Lyrae at a distance of 298.14 light years or 91.41 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.

The star's Galacto-Centric Distance is 7,376.00 Parsecs or 24,057.81 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

Variable Type of R Lyrae

The star is a pulsating Semiregular late- (M, C, S or Me, Ce, Se) giants with poorly defined periodicity 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. R Lyrae brightness ranges from a magnitude of 4.135 to a magnitude of 3.821 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.

R Lyrae Facts

Alternative Names

Traditional/Proper NameR Lyrae
Flamsteed Name13 Lyrae
Flamsteed Short Name13 Lyr
Short NameR Lyr
Hipparcos Library I.D.92862
Yale Bright Star Catalogue (HR) Id7157
Bonner DurchmusterungBD+43 3117
Henry Draper Designation175865

Visual Facts

Star Type star
Absolute Magnitude-1.07 / -0.72
Visual / Apparent Magnitude4.08
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)18h 55m 20.09
Declination (Dec.)+43d 56` 45.2
Galactic Latitude17.79 degrees
Galactic Longitude73.81 degrees
1997 Distance from Earth9.33 Parallax (milliarcseconds)
 349.59 Light Years
 107.18 Parsecs
2007 Revised Distance from Earth10.94 Parallax (milliarcseconds)
 298.14 Light Years
 91.41 Parsecs
Galacto-Centric Distance24,057.81 Light Years / 7,376.00 Parsecs
Proper Motion Dec.82.06 ± 0.11 milliarcseconds/year
Proper Motion RA.21.05 ± 0.12 milliarcseconds/year
B-V Index1.39
Radial Velocity-27.15 ± 0.20 km/s
Spectral TypeM5IIIvar
Colour(M) Red

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeSemiregular late- (M, C, S or Me, Ce, Se) giants with poorly defined periodicity
Mean Variability Period in Days0.266
Variable Magnitude Range (Brighter - Dimmer)3.821 - 4.135

Estimated Facts

Calculated Effective Temperature4,176 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Location of R Lyrae in Lyra

R Lyrae Location in Lyra

The map was generated using Night Vision, an awesome free application by Brian Simpson.

Add a Comment

Email: (Optional)