Universe Guide

HomeFactsConstellationsChamaeleon

Alpha Chamaeleontis - HD71243 - HIP40702

Alpha Chamaeleontis is a blue to white giant star that can be located in the constellation of Chamaeleon. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it. The star has an estimated age of 1.50 Billion of Years but could be as young as 1.40 to 1.60 according to Hipparcos.

Alpha Chamaeleontis is the Bayer Classification for the star. HIP40702 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD71243. The Gliese ID of the star is Gliese GL305. The star was part of the original catalogue devised by German Astronomer Wilheim Gliese of stars located within 20 parsecs of Earth. Ref : Star Names.

Location of Alpha Chamaeleontis

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 Alpha Chamaeleontis, the location is 08h 18m 31.27 and -76d55`11.9 .

Proper Motion of Alpha Chamaeleontis

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 107.49 ± 0.11 miliarcseconds/year towards the north and 111.12 ± 0.12 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Age, Radius) of Alpha Chamaeleontis

Alpha Chamaeleontis has a spectral type of F5III. This means the star is a blue to white giant star. The star is 7394.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24116.5176553600000000s. The star has a B-V Colour Index of 0.41 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 6,681 Kelvin.

Alpha Chamaeleontis Radius has been calculated as being 2.10 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,464,466.23.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 2.11. 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 0.05 with an error value of 0.08 Fe/H with the Sun has a value of 1 to put it into context.

The stars age according to Hipparcos data files put the star at an age of about 1.50 Billion years old but could be between 1.40 and 1.60 Billion years old. In comparison, the Sun's age is about 4.6 Billion Years Old.

Alpha Chamaeleontis Apparent and Absolute Magnitudes

Alpha Chamaeleontis has an apparent magnitude of 4.05 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 2.60 If you used the 2007 Parallax value, you would get an absolute magnitude of 2.59. 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 Alpha Chamaeleontis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 51.40 which gave the calculated distance to Alpha Chamaeleontis as 63.46 light years away from Earth or 19.46 parsecs. It would take a spaceship travelling at the speed of light, 63.46 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 51.12 which put Alpha Chamaeleontis at a distance of 63.80 light years or 19.56 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 7,394.00 Parsecs or 24,116.52 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

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.

Alpha Chamaeleontis Facts

Alternative Names

Bayer DesignationAlpha Chamaeleontis
Hipparcos Library I.D.40702
Gliese ID305
Henry Draper Designation71243

Visual Facts

Star Typegiant star
Age1.50 Billion Years Old
Age Range1.40 - 1.60 Billion Years Old
Absolute Magnitude2.60 / 2.59
Visual / Apparent Magnitude4.05
Naked Eye VisibleYes - Ref: Wiki
Right Ascension (R.A.)08h 18m 31.27
Declination (Dec.)-76d55`11.9
Galactic Latitude-21.68 degrees
Galactic Longitude289.86 degrees
1997 Distance from Earth51.40 Parallax (milliarcseconds)
 63.46 Light Years
 19.46 Parsecs
2007 Revised Distance from Earth51.12 Parallax (milliarcseconds)
 63.80 Light Years
 19.56 Parsecs
Galacto-Centric Distance24,116.52 Light Years / 7,394.00 Parsecs
Proper Motion Dec.107.49 ± 0.11 milliarcseconds/year
Proper Motion RA.111.12 ± 0.12 milliarcseconds/year
B-V Index0.41
Radial Velocity-13.40 ± 0.50 km/s
Iron Abundance0.05 ± 0.08 Fe/H
Spectral TypeF5III
Colour(F) blue to white

Estimated Facts

Calculated Effective Temperature6,681 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Location of Alpha Chamaeleontis in Chamaeleon


Alpha Chamaeleontis (Alpha Chamaeleontis) Location in Chamaeleon

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


Add a Comment


Name:
Email: (Optional)
Comment: