Universe Guide


V Microscopii, HD203495, HIP105638

V Microscopii is a red star that can be located in the constellation of Microscopium. V Microscopii is the brightest star in Microscopium based on the Hipparcos 2007 apparent magnitude. The star can not be seen by the naked eye, you need a telescope to see it.

HIP105638 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD203495.

Location of V Microscopii

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 V Microscopii, the location is 21h 23m 48.76 and -40d42`05.1 .

Proper Motion of V Microscopii

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 -3.12 ± 6.10 miliarcseconds/year towards the north and 12.57 ± 8.65 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of V Microscopii

V Microscopii has a spectral type of M4e. This means the star is a red star. The star has a B-V Colour Index of 1.5 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,014 Kelvin.

V Microscopii Radius has been calculated as being 0.31 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 214,854.74.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 4.19. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

V Microscopii Apparent and Absolute Magnitudes

V Microscopii has an apparent magnitude of 12.37 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 8.98 If you used the 2007 Parallax value, you would get an absolute magnitude of 3.32. 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 V Microscopii

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 21.01 which gave the calculated distance to V Microscopii as 155.24 light years away from Earth or 47.60 parsecs. It would take a spaceship travelling at the speed of light, 155.24 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 1.55 which put V Microscopii at a distance of 2104.28 light years or 645.16 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.

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.

V Microscopii Facts

Alternative Names

Traditional/Proper NameV Microscopii
Hipparcos Library I.D.105638
Henry Draper Designation203495

Visual Facts

Star Type star
Absolute Magnitude8.98 / 3.32
Visual / Apparent Magnitude12.37
Naked Eye VisibleRequires a 4.5 - 6 Inch Telescope - Magnitudes
Right Ascension (R.A.)21h 23m 48.76
Declination (Dec.)-40d42`05.1
Galactic Latitude-45.53 degrees
Galactic Longitude1.33 degrees
1997 Distance from Earth21.01 Parallax (milliarcseconds)
 155.24 Light Years
 47.60 Parsecs
2007 Revised Distance from Earth1.55 Parallax (milliarcseconds)
 2104.28 Light Years
 645.16 Parsecs
Proper Motion Dec.-3.12 ± 6.10 milliarcseconds/year
Proper Motion RA.12.57 ± 8.65 milliarcseconds/year
B-V Index1.50
Radial Velocity-6.50 ± 999.00 km/s
Spectral TypeM4e
Colour(M) Red

Estimated Facts

Calculated Effective Temperature4,014 Kelvin

Sources and Links

SIMBAD SourceLink

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