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Rigel (Beta Orionis) - HD34085 - HIP24436 - HR1713

Rigel (Beta Orionis) is a blue pulsating very luminous supergiant star that can be located in the constellation of Orion. It is the 8th brightest star in the night sky. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

Beta Orionis is the Bayer Classification for the star. The Id of the star in the Yale Bright Star Catalogue is HR1713. HIP24436 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD34085.

Rigel has alternative name(s), 19 Orionis , bet_Ori, 19 Ori. In Arabic, it is known as Ar-Rijl.

Rigel is one of the brightest stars in the northern hemisphere that is easy to locate in the sky. This is due in part thanks to the unmistakable belt of Orion, three stars in diagonal line. Once you have spotted the line, you just work your way down diagonally from the right send star which is Mintaka. It is a bright blue star compared to our own white-yellow star, The Sun.

It is a multi-star system with two smaller, dimmer companion stars orbiting round it. As it is a giant star compared to our own, it will burn its hydrogen at a faster rate that the Sun, life fast and die young. It is a Main Sequence star which means it is currently burning through its hydrogen into helium.

Rigel one character different from the English name Nigel has been used as character names. In the eighties there was a comic strip in a computer magazine called "Nigel from Rigel" but more famously, the Farscape character Dominar Rygel XVI is also inspired by the name. aliens from this part of the milky way are inevitably known as Rigellians.

Location of Rigel

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 Rigel, the location is 05h 14m 32.27 and -08d12`05.9 .

Proper Motion of Rigel

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 0.50 ± 0.25 miliarcseconds/year towards the north and 1.31 ± 0.34 miliarcseconds/year east if we saw them in the horizon.

Rigel 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 73000.0000000 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 Rigel

Rigel has a spectral type of B8Ia. This means the star is a blue supergiant star. The star is 7608.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24814.5072115200000000s. The star has a B-V Colour Index of -0.03 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 11,122 Kelvin.

Rigel Radius has been calculated as being 54.78 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 38,114,280.69.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 61.18. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

Rigel Apparent and Absolute Magnitudes

Rigel has an apparent magnitude of 0.18 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 -6.69 If you used the 2007 Parallax value, you would get an absolute magnitude of -6.93. 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 Rigel

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 4.22 which gave the calculated distance to Rigel as 772.90 light years away from Earth or 236.97 parsecs. It would take a spaceship travelling at the speed of light, 772.90 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 3.78 which put Rigel at a distance of 862.87 light years or 264.55 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 7,608.00 Parsecs or 24,814.51 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 Rigel

The star is a pulsating Alpha Cygnus 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. Rigel brightness ranges from a magnitude of 0.000 to a magnitude of 0.000 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 2.0 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.

Rigel Facts

Alternative Names

Traditional/Proper NameRigel
Short Namebet Ori, 19 Ori
Arabic NameAr-Rijl
English MeaningThe foot
Bayer DesignationBeta Orionis
Alternative Name(s)19 Orionis
Hipparcos Library I.D.24436
Yale Bright Star Catalogue (HR) Id1713
Bonner DurchmusterungBDD-08 1063
Henry Draper Designation34085

Visual Facts

Star Typesupergiant star
Absolute Magnitude-6.69 / -6.93
Visual / Apparent Magnitude0.18
Naked Eye VisibleYes - Ref: Wiki
Right Ascension (R.A.)05h 14m 32.27
Declination (Dec.)-08d12`05.9
Galactic Latitude-25.25 degrees
Galactic Longitude209.24 degrees
1997 Distance from Earth4.22 Parallax (milliarcseconds)
 772.90 Light Years
 236.97 Parsecs
2007 Revised Distance from Earth3.78 Parallax (milliarcseconds)
 862.87 Light Years
 264.55 Parsecs
Galacto-Centric Distance24,814.51 Light Years / 7,608.00 Parsecs
Proper Motion Dec.0.50 ± 0.25 milliarcseconds/year
Proper Motion RA.1.31 ± 0.34 milliarcseconds/year
B-V Index-0.03
Radial Velocity17.80 ± 0.40 km/s
Spectral TypeB8Ia
Brightest in Night Sky8th
Colour(B) blue

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeAlpha Cygnus
Mean Variability Period in Days2.000

Estimated Facts

Luminosity (x the Sun)73,000.0000000
Calculated Effective Temperature11,122 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Multi-Star System

The star has been identified as being a multi-star system, one in which there is at least one star in close orbit to another star or two or more stars orbiting a central point. The stars may be of equal mass, unequal mass where one star is stronger than the other or be in groups orbiting a central point which doesn't necessarily have to be a star. More information can be found on my dedicated multiple star systems page. The source of the info is Simbad. The file is dated 2000 so any differences between this and any other source will be down to the actual source from where the information came from.


Proper Motion mas/yr
H.D. IdB.D. IdStar CodeMagnitudeR.A.Dec.SpectrumColourYear
34085-08 1063.0A0.30000-4.00000-2.00000B8Blue/White
B10.400001831
BC10.400001959
D15.400001921

Location of Rigel in Orion


Rigel (Beta Orionis) Location in Orion

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


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