Universe Guide

Alpha Chamaeleontis

Alpha Chamaeleontis Facts

  • Alpha Chamaeleontis is a giant star that can be located in the constellation of Chamaeleon. The description is based on the spectral class.
  • Alpha Chamaeleontis is a main star of the constellation outline.
  • Based on the spectral type (F5III) of the star, the star's colour is yellow to white .
  • Alpha Chamaeleontis is the 1st brightest star in Chamaeleon 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.
  • 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.
  • Using the most recent figures given by the 2007 Hipparcos data, the star is 63.80 light years away from us. Distance

Alpha Chamaeleontis's Alternative Names

Alpha Chamaeleontis (Alf Cha) is the Bayer Classification for the star. The Bayer Classification was created by Johann Bayer in 1603. The brightest star in the constellation is normally given the Alpha designation, there are exceptions such as Pollux which is Beta Geminorum.

The Id of the star in the Yale Bright Star Catalogue is HR3318. 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 GL 305. The star was part of the original catalogue devised by German Astronomer Wilheim Gliese of stars located within 20 parsecs of Earth. Star Names

More details on objects' alternative names can be found at Star Names .

Location of Alpha Chamaeleontis

The location of the giant star in the night sky 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 object is compared to the celestial equator and is expressed in degrees. For Alpha Chamaeleontis, the location is 08h 18m 31.27 and -76° 55` 11.9 .

Radial Velocity and Proper Motion of Alpha Chamaeleontis

Proper Motion

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

Radial Velocity

The Radial Velocity, that is the speed at which the star is moving away/towards the Sun is -13.40000 km/s with an error of about 0.50 km/s . When the value is negative then the star and the Sun are getting closer to one another, likewise, a positive number means that two stars are moving away. Its nothing to fear as the stars are so far apart, they won't collide in our life-time, if ever.

Physical Properties of Alpha Chamaeleontis

Alpha Chamaeleontis Temperature and Colour

Based on the star's spectral type of F5III , Alpha Chamaeleontis's colour and type is yellow to white giant star. The star's effective temperature is 6,625 Kelvin which is hotter than our own Sun's effective Temperature which is 5,777 Kelvin.

Alpha Chamaeleontis 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 7.72 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.

Alpha Chamaeleontis Radius

Alpha Chamaeleontis estimated 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. If you need the diameter of the star, you just need to multiple the radius by 2. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 2.1144383880179581574228724825. The figure is derived at by using the formula from SDSS rather than peer reviewed papers. It has been known to produce widely incorrect figures.

Alpha Chamaeleontis Iron Abundance

Alpha Chamaeleontis 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 value comes from the Hipparcos Extended Catalog.

Alpha Chamaeleontis Estimated Age

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 51.40000 which gave the calculated distance to Alpha Chamaeleontis as 63.46 light years away from Earth or 19.46 parsecs. If you want that in miles, it is about 373,057,566,182,231.89, based on 1 Ly = 5,878,625,373,183.61 miles.

In 2007, Hipparcos data was revised with a new parallax of 51.12000 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.

Using the 2007 distance, the star is roughly 4,034,511.50 Astronomical Units from the Earth/Sun give or take a few. An Astronomical Unit is the distance between Earth and the Sun. The number of A.U. is the number of times that the star is from the Earth compared to the Sun. 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*.

Travel Time to Alpha Chamaeleontis

The time it will take to travel to this star is dependent on how fast you are going. U.G. has done some calculations as to how long it will take going at differing speeds. A note about the calculations, when I'm talking about years, I'm talking non-leap years only (365 days).

The New Horizons space probe is the fastest probe that we've sent into space at the time of writing. Its primary mission was to visit Pluto which at the time of launch (2006), Pluto was still a planet.

DescriptionSpeed (m.p.h.)Time (years)
Airbus A38073658,132,256.70
Speed of Sound (Mach 1)767.26955,763,155.99
Concorde (Mach 2)1,534.5427,881,541.65
New Horizons Probe33,0001,296,525.48
Speed of Light670,616,629.0063.80

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.

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Additional Alpha Chamaeleontis Facts and Figures

Visual Facts

Primary / Proper / Traditional NameAlpha Chamaeleontis
Alternative NamesAlf Cha, HD 71243, HIP 40702, HR 3318, Gliese 305
Spectral TypeF5III
Constellation's Main StarYes
Multiple Star SystemNo / Unknown
Star TypeGiant Star
ColourYellow - White
GalaxyMilky Way
Age1.50 Billion Years Old
Age Range1.40 - 1.60 Billion Years Old
Absolute Magnitude 2.60 / 2.59
Visual / Apparent Magnitude4.05
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)08h 18m 31.27
Declination (Dec.)-76° 55` 11.9
Galactic Latitude-21.68168051 degrees
Galactic Longitude289.86015054 degrees
1997 Distance from Earth51.40000 Parallax (milliarcseconds)
 63.46 Light Years
 19.46 Parsecs
2007 Distance from Earth51.12000 Parallax (milliarcseconds)
 63.80 Light Years
 19.56 Parsecs
 4,034,511.50 Astronomical Units
Galacto-Centric Distance24,116.52 Light Years / 7,394.00 Parsecs
Proper Motion Dec.107.49000 ± 0.11000 milliarcseconds/year
Proper Motion RA.111.12000 ± 0.12000 milliarcseconds/year
B-V Index0.41
Radial Velocity-13.40000 ± 0.50 km/s
Iron Abundance0.0500 ± 0.08 Fe/H
Semi-Major Axis9188.0000000
Stellar Luminosity (Lsun)7.7200000

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Estimated Calculated Facts

Radius (x the Sun)2.11
Effective Temperature6,681 Kelvin

Sources and Links

SIMBAD SourceLink

Location of Alpha Chamaeleontis in Chamaeleon

Alpha Chamaeleontis Location in Chamaeleon

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

Chamaeleon Main Stars

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