Universe Guide


CO Lacertae, HD240058, HIP112436

CO Lacertae is a blue eclipsing main sequence dwarf star that can be located in the constellation of Lacerta. The star can not be seen by the naked eye, you need a telescope to see it.

HIP112436 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD240058.

CO Lacertae has alternative name(s), CO Lac.

Location of CO Lacertae

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 CO Lacertae, the location is 22h 46m 30.00 and +56d49`31.6 .

CO Lacertae Luminosity

Luminosity is the amount of energy that a star pumps out and its relative to the amount that our star, the Sun gives out. The figure of 42.0000000 that I have given is based on the Spectral Types page that I have found on the Internet. You might find a different figure, one that may have been calculated rather than generalised that I have done. The figure is always the amount times the luminosity of the Sun. It is an imprecise figure because of a number of factors including but not limited to whether the star is a variable star and distance.

Physical Properties (Colour, Temperature, Radius) of CO Lacertae

CO Lacertae has a spectral type of B9V. This means the star is a blue main sequence dwarf star. The star has a B-V Colour Index of 0.06 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 8,815 Kelvin. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

CO Lacertae Apparent and Absolute Magnitudes

CO Lacertae has an apparent magnitude of 10.40 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 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 CO Lacertae

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as -0.61 which gave the calculated distance to CO Lacertae as -5346.94 light years away from Earth or -1639.34 parsecs. It would take a spaceship travelling at the speed of light, -5346.94 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

Variable Type of CO Lacertae

The star is a eclipsing Beta Persei (Algol)/Detached Main Sequence (subtype) 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. CO Lacertae brightness ranges from a magnitude of 11.020 to a magnitude of 10.413 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 1.5 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.

CO Lacertae Facts

Alternative Names

Traditional/Proper NameCO Lacertae
Short NameCO Lac
Hipparcos Library I.D.112436
Bonner DurchmusterungBD+56 2857
Henry Draper Designation240058

Visual Facts

Star Typemain sequence dwarf star
Visual / Apparent Magnitude10.40
Naked Eye VisibleRequires a 4.5 - 6 Inch Telescope - Magnitudes
Right Ascension (R.A.)22h 46m 30.00
Declination (Dec.)+56d49`31.6
Galactic Latitude-1.99 degrees
Galactic Longitude106.44 degrees
1997 Distance from Earth-0.61 Parallax (milliarcseconds)
 -5346.94 Light Years
 -1639.34 Parsecs
B-V Index0.06
Radial Velocity-32.50 ± 7.40 km/s
Spectral TypeB9V
Colour(B) blue

Variable Star Details

Variable Star ClassEclipsing
Variable Star TypeBeta Persei (Algol)/Detached Main Sequence (subtype)
Mean Variability Period in Days1.542
Variable Magnitude Range (Brighter - Dimmer)10.413 - 11.020

Estimated Facts

Luminosity (x the Sun)42.0000000
Calculated Effective Temperature8,815 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

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