Universe Guide


Lambda Columbae, HD39764, HIP27810

Lambda Columbae is a blue pulsating main sequence dwarf star that can be located in the constellation of Columba. Lambda Columbae is the brightest star in Columba based on the Hipparcos 2007 apparent magnitude. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

Lambda Columbae is the Bayer Classification for the star. HIP27810 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD39764.

Lambda Columbae has alternative name(s), lam Col.

Location of Lambda Columbae

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 Lambda Columbae, the location is 05h 53m 06.88 and -33d48`05.2 .

Proper Motion of Lambda Columbae

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 31.32 ± 0.17 miliarcseconds/year towards the north and -4.72 ± 0.21 miliarcseconds/year east if we saw them in the horizon.

Lambda Columbae 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 380.0000000 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 Lambda Columbae

Lambda Columbae has a spectral type of B5V. This means the star is a blue main sequence dwarf star. The star is 7447.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24289.3842276800000000s. The star has a B-V Colour Index of -0.15 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 13,674 Kelvin.

Lambda Columbae Radius has been calculated as being 1.84 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,281,146.63.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 1.80. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

Lambda Columbae Apparent and Absolute Magnitudes

Lambda Columbae has an apparent magnitude of 4.88 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 -0.22 If you used the 2007 Parallax value, you would get an absolute magnitude of -0.17. 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 Lambda Columbae

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 9.55 which gave the calculated distance to Lambda Columbae as 341.53 light years away from Earth or 104.71 parsecs. It would take a spaceship travelling at the speed of light, 341.53 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 9.75 which put Lambda Columbae at a distance of 334.53 light years or 102.56 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 7,447.00 Parsecs or 24,289.38 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 Lambda Columbae

The star is a pulsating Beta Cephei 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. Lambda Columbae brightness ranges from a magnitude of 4.849 to a magnitude of 4.816 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.

Lambda Columbae Facts

Alternative Names

Short Namelam Col
Bayer DesignationLambda Columbae
Hipparcos Library I.D.27810
Henry Draper Designation39764

Visual Facts

Star Typemain sequence dwarf star
Absolute Magnitude-0.22 / -0.17
Visual / Apparent Magnitude4.88
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)05h 53m 06.88
Declination (Dec.)-33d48`05.2
Galactic Latitude-26.09 degrees
Galactic Longitude239.36 degrees
1997 Distance from Earth9.55 Parallax (milliarcseconds)
 341.53 Light Years
 104.71 Parsecs
2007 Revised Distance from Earth9.75 Parallax (milliarcseconds)
 334.53 Light Years
 102.56 Parsecs
Galacto-Centric Distance24,289.38 Light Years / 7,447.00 Parsecs
Proper Motion Dec.31.32 ± 0.17 milliarcseconds/year
Proper Motion RA.-4.72 ± 0.21 milliarcseconds/year
B-V Index-0.15
Radial Velocity30.00 ± 2.80 km/s
Spectral TypeB5V
Colour(B) blue

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeBeta Cephei
Mean Variability Period in Days0.643
Variable Magnitude Range (Brighter - Dimmer)4.816 - 4.849

Estimated Facts

Luminosity (x the Sun)380.0000000
Calculated Effective Temperature13,674 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

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