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FN Canis Majoris, HD53974, HIP34301

FN Canis Majoris is a blue pulsating subgiant star that can be located in the constellation of CanisMajor. FN Canis Majoris is the brightest star in Canis Major 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.

HIP34301 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD53974.

FN Canis Majoris has alternative name(s), FN CMa.

Location of FN Canis Majoris

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 FN Canis Majoris, the location is 07h 06m 40.77 and -11d17`38.5 .

Proper Motion of FN Canis Majoris

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 3.32 ± 0.44 miliarcseconds/year towards the north and -3.14 ± 0.61 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of FN Canis Majoris

FN Canis Majoris has a spectral type of B0.5IV. This means the star is a blue subgiant star. 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 9,140 Kelvin.

FN Canis Majoris Radius has been calculated as being 26.86 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 18,686,912.67.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 28.78. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

FN Canis Majoris Apparent and Absolute Magnitudes

FN Canis Majoris has an apparent magnitude of 5.41 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 -4.29 If you used the 2007 Parallax value, you would get an absolute magnitude of -4.44. 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 FN Canis Majoris

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 1.15 which gave the calculated distance to FN Canis Majoris as 2836.20 light years away from Earth or 869.57 parsecs. It would take a spaceship travelling at the speed of light, 2836.20 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 1.07 which put FN Canis Majoris at a distance of 3048.26 light years or 934.58 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.

Variable Type of FN Canis Majoris

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. FN Canis Majoris brightness ranges from a magnitude of 5.429 to a magnitude of 5.396 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.0 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.

FN Canis Majoris Facts

Alternative Names

Traditional/Proper NameFN Canis Majoris
Short NameFN CMa
Hipparcos Library I.D.34301
Bonner DurchmusterungBD-11 1790
Henry Draper Designation53974

Visual Facts

Star Typesubgiant star
Absolute Magnitude-4.29 / -4.44
Visual / Apparent Magnitude5.41
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)07h 06m 40.77
Declination (Dec.)-11d17`38.5
Galactic Latitude-1.79 degrees
Galactic Longitude224.71 degrees
1997 Distance from Earth1.15 Parallax (milliarcseconds)
 2836.20 Light Years
 869.57 Parsecs
2007 Revised Distance from Earth1.07 Parallax (milliarcseconds)
 3048.26 Light Years
 934.58 Parsecs
Proper Motion Dec.3.32 ± 0.44 milliarcseconds/year
Proper Motion RA.-3.14 ± 0.61 milliarcseconds/year
B-V Index0.03
Radial Velocity31.00 ± 4.20 km/s
Spectral TypeB0.5IV
Colour(B) blue

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeBeta Cephei
Mean Variability Period in Days0.023
Variable Magnitude Range (Brighter - Dimmer)5.396 - 5.429

Estimated Facts

Calculated Effective Temperature9,140 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
53974-11 1790.0A5.60000-13.000002.00000B3Blue/White
B6.800001950
C9.000001879

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