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Mira, Omicron Ceti, 68 Ceti, HD14386, HIP10826, HR681

Mira (Omicron Ceti) is a red pulsating star that can be located in the constellation of Cetus. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

Omicron Ceti is the Bayer Classification for the star. The Id of the star in the Yale Bright Star Catalogue is HR681. HIP10826 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD14386. The Id of the star in the Gould Star Catalogue is 233. Stars in the southern hemisphere are more likely to have a Gould Id than the northern hemisphere. For example, there are no Gould classified stars in Ursa Major.

Mira has alternative name(s), omi Cet.

Location of Mira

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 Mira, the location is 02h 19m 20.79 and -02d58`37.4 .

Proper Motion of Mira

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 -237.36 ± 1.31 miliarcseconds/year towards the north and 9.33 ± 1.22 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of Mira

Mira has a spectral type of M5e-M9e. This means the star is a red star. The star is 7466.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24351.3552630400000000s. The star has a B-V Colour Index of 0.96 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,060 Kelvin.

Mira Radius has been calculated as being 7.92 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 5,509,062.08.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 5.66. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

Mira Apparent and Absolute Magnitudes

Mira has an apparent magnitude of 6.47 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 0.93 If you used the 2007 Parallax value, you would get an absolute magnitude of 1.66. 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 Mira

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 7.79 which gave the calculated distance to Mira as 418.69 light years away from Earth or 128.37 parsecs. It would take a spaceship travelling at the speed of light, 418.69 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 10.91 which put Mira at a distance of 298.96 light years or 91.66 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 7,466.00 Parsecs or 24,351.36 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 Mira

The star is a pulsating Omicron Ceti 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. Mira brightness ranges from a magnitude of 7.321 to a magnitude of 2.935 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 333.8 days (variability).

Meteor Showers Radiating from near Mira

The Omicron Cetids Meteor Shower radiants from a point near this star. The meteor shower runs typically between May 7-June 9 with a peak date of May 14-25.

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.

Mira Facts

Alternative Names

Traditional/Proper NameMira
Flamsteed Name68 Ceti
Flamsteed Short Name68 Cet
Short Nameomi Cet
Bayer DesignationOmicron Ceti
Hipparcos Library I.D.10826
Yale Bright Star Catalogue (HR) Id681
Bonner DurchmusterungBD-03 353
Gould I.D.233
Henry Draper Designation14386

Visual Facts

Star Type star
Absolute Magnitude0.93 / 1.66
Visual / Apparent Magnitude6.47
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)02h 19m 20.79
Declination (Dec.)-02d58`37.4
Galactic Latitude-57.98 degrees
Galactic Longitude167.75 degrees
1997 Distance from Earth7.79 Parallax (milliarcseconds)
 418.69 Light Years
 128.37 Parsecs
2007 Revised Distance from Earth10.91 Parallax (milliarcseconds)
 298.96 Light Years
 91.66 Parsecs
Galacto-Centric Distance24,351.36 Light Years / 7,466.00 Parsecs
Proper Motion Dec.-237.36 ± 1.31 milliarcseconds/year
Proper Motion RA.9.33 ± 1.22 milliarcseconds/year
B-V Index0.96
Radial Velocity63.50 ± 0.60 km/s
Spectral TypeM5e-M9e
Colour(M) Red

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeOmicron Ceti
Mean Variability Period in Days333.800
Variable Magnitude Range (Brighter - Dimmer)2.935 - 7.321

Estimated Facts

Calculated Effective Temperature5,060 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
14386-03 353.0A-13.00000-233.00000M4Red
B13.000001911
14411-03 355.0C9.30000-6.00000-17.00000M1Red1925
P9.700001923

Location of Mira in Cetus


Mira (Omicron Ceti) Location in Cetus

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


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