Universe Guide

BT Microscopii

BT Microscopii Facts

  • BT Microscopii is a eclipsing binary sys main sequence star that can be located in the constellation of Microscopium. The description is based on the spectral class.
  • BT Microscopii is not part of the constellation outline but is within the borders of the constellation.
  • Based on the spectral type (F3V) of the star, the star's colour is yellow to white .
  • The star can not be seen by the naked eye, you need a telescope to see it.
  • Using the most recent figures given by the 2007 Hipparcos data, the star is 789.74 light years away from us. Distance

BT Microscopii's Alternative Names

HIP101977 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD196583.

BT Microscopii has alternative name(s) :- BT Mic, BT Mic.

More details on objects' alternative names can be found at Star Names .

Location of BT Microscopii

The location of the main sequence star in the night sky 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 object is compared to the celestial equator and is expressed in degrees. For BT Microscopii, the location is 20h 39m 57.31 and -43° 36` 22.9 .

Proper Motion of BT 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 -15.31 ± 0.94 milliarcseconds/year towards the north and 6.14 ± 1.72 milliarcseconds/year east if we saw them in the horizon. . When the value is negative then the star and the Sun are getting closer to one another, likewise, a positive number means that two stars are moving away. Its nothing to fear as the stars are so far apart, they won't collide in our life-time, if ever.

Physical Properties of BT Microscopii

BT Microscopii Temperature and Colour

Based on the star's spectral type of F3V , BT Microscopii's colour and type is yellow to white main sequence star. The star has a B-V Colour Index of 0.45 which means the star's temperature is about 6,500 Kelvin. The temperature was calculated using information from Morgans @ Uni.edu.

BT Microscopii Radius

BT Microscopii estimated radius has been calculated as being 2.24 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,561,477.71.km. If you need the diameter of the star, you just need to multiple the radius by 2. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 1.7260197757053474519435793093. The figure is derived at by using the formula from SDSS rather than peer reviewed papers. It has been known to produce widely incorrect figures.

BT Microscopii Apparent and Absolute Magnitudes

BT Microscopii has an apparent magnitude of 10.07 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 2.58 If you used the 2007 Parallax value, you would get an absolute magnitude of 3.15. 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 BT Microscopii

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 3.17000 which gave the calculated distance to BT Microscopii as 1028.91 light years away from Earth or 315.46 parsecs. If you want that in miles, it is about 6,048,576,432,722,348.17, based on 1 Ly = 5,878,625,373,183.61 miles.

In 2007, Hipparcos data was revised with a new parallax of 4.13000 which put BT Microscopii at a distance of 789.74 light years or 242.13 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.

Using the 2007 distance, the star is roughly 49,942,549.53 Astronomical Units from the Earth/Sun give or take a few. An Astronomical Unit is the distance between Earth and the Sun. The number of A.U. is the number of times that the star is from the Earth compared to the Sun.

Travel Time to BT Microscopii

The time it will take to travel to this star is dependent on how fast you are going. U.G. has done some calculations as to how long it will take going at differing speeds. A note about the calculations, when I'm talking about years, I'm talking non-leap years only (365 days).

The New Horizons space probe is the fastest probe that we've sent into space at the time of writing. Its primary mission was to visit Pluto which at the time of launch (2006), Pluto was still a planet.

DescriptionSpeed (m.p.h.)Time (years)
Airbus A380736719,582,576.88
Speed of Sound (Mach 1)767.269690,256,971.92
Concorde (Mach 2)1,534.54345,128,036.15
New Horizons Probe33,00016,048,872.02
Speed of Light670,616,629.00789.74

Variable Type of BT Microscopii

The star is a eclipsing binary sys Beta Lyrae (Sheliak) 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. BT Microscopii brightness ranges from a magnitude of 10.415 to a magnitude of 10.143 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 1.5 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.

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Additional BT Microscopii Facts and Figures

Visual Facts

Primary / Proper / Traditional NameBT Microscopii
Alternative NamesBT Mic, HD 196583, HIP 101977, BT Mic
Spectral TypeF3V
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star Type Main Sequence Dwarf Star
ColourYellow - White
GalaxyMilky Way
Absolute Magnitude 2.58 / 3.15
Visual / Apparent Magnitude10.07
Naked Eye VisibleRequires a 4.5 - 6 Inch Telescope - Magnitudes
Right Ascension (R.A.)20h 39m 57.31
Declination (Dec.)-43° 36` 22.9
Galactic Latitude-37.47065831 degrees
Galactic Longitude357.22053206 degrees
1997 Distance from Earth3.17000 Parallax (milliarcseconds)
 1028.91 Light Years
 315.46 Parsecs
2007 Distance from Earth4.13000 Parallax (milliarcseconds)
 789.74 Light Years
 242.13 Parsecs
 49,942,549.53 Astronomical Units
Proper Motion Dec.-15.31000 ± 0.94000 milliarcseconds/year
Proper Motion RA.6.14000 ± 1.72000 milliarcseconds/year
B-V Index0.45

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Variable Star ClassEclipsing binary sys
Variable Star TypeBeta Lyrae (Sheliak)
Mean Variability Period in Days1.506
Variable Magnitude Range (Brighter - Dimmer)10.143 - 10.415

Estimated Calculated Facts

Radius (x the Sun)1.73
Effective Temperature6,500 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Comments and Questions

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