Universe Guide


FU Monocerotis, HD44544, HIP30301

FU Monocerotis is a pulsating star that can be located in the constellation of Monoceros. The star can not be seen by the naked eye, you need a telescope to see it.

HIP30301 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD44544.

FU Monocerotis has alternative name(s), FU Mon.

Location of FU Monocerotis

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 FU Monocerotis, the location is 06h 22m 23.85 and +03d25`28.0 .

Proper Motion of FU Monocerotis

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 -9.55 ± 0.93 miliarcseconds/year towards the north and 3.02 ± 1.53 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Temperature, Radius) of FU Monocerotis

FU Monocerotis has a spectral type of Sevar. This means the star is a star. The star has a B-V Colour Index of 3.17 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 0 Kelvin. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

FU Monocerotis Apparent and Absolute Magnitudes

FU Monocerotis has an apparent magnitude of 9.76 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 -2.85 If you used the 2007 Parallax value, you would get an absolute magnitude of 0.35. 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 FU Monocerotis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 0.30 which gave the calculated distance to FU Monocerotis as 10872.11 light years away from Earth or 3333.33 parsecs. It would take a spaceship travelling at the speed of light, 10872.11 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 1.31 which put FU Monocerotis at a distance of 2489.80 light years or 763.36 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 FU Monocerotis

The star is a pulsating Semi-Regular Star which are giants or supergiants of intermediate and late spectral 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. FU Monocerotis brightness ranges from a magnitude of 8.772 to a magnitude of 7.992 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 340.0 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.

FU Monocerotis Facts

Alternative Names

Traditional/Proper NameFU Monocerotis
Short NameFU Mon
Hipparcos Library I.D.30301
Bonner DurchmusterungBD+03 1214
Henry Draper Designation44544

Visual Facts

Star Type star
Absolute Magnitude-2.85 / 0.35
Visual / Apparent Magnitude9.76
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)06h 22m 23.85
Declination (Dec.)+03d25`28.0
Galactic Latitude-4.88 degrees
Galactic Longitude206.55 degrees
1997 Distance from Earth0.30 Parallax (milliarcseconds)
 10872.11 Light Years
 3333.33 Parsecs
2007 Revised Distance from Earth1.31 Parallax (milliarcseconds)
 2489.80 Light Years
 763.36 Parsecs
Proper Motion Dec.-9.55 ± 0.93 milliarcseconds/year
Proper Motion RA.3.02 ± 1.53 milliarcseconds/year
B-V Index3.17
Radial Velocity-26.20 ± 0.80 km/s
Spectral TypeSevar

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeSemi-Regular Star which are giants or supergiants of intermediate and late spectral
Mean Variability Period in Days340.000
Variable Magnitude Range (Brighter - Dimmer)7.992 - 8.772

Estimated Facts

Sources and Links

SIMBAD SourceLink

Related Stars

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