Theta1 Orionis A is a blue star that can be located in the constellation of Orion. Theta1 Orionis A is the brightest star in Orion 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.
Theta1 Orionis A is the Bayer Classification for the star. HIP26220 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD37020.
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 Theta1 Orionis A, the location is 05h 35m 15.82 and -05 d 23 ` 14.3 .
Theta1 Orionis A has a spectral type of O7. This means the star is a blue star. The star is 7920.00000000 Parsecs from the Galactic Centre or terms of Light Years is 25832.1368448000000000s. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.
The star has a companion star which is in orbit close by, it has at least the following companions in close orbit, .
Theta1 Orionis A has an apparent magnitude of 4.98 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 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.
Using the original Hipparcos data that was released in 1997, the parallax to the star was given as -2.00 which gave the calculated distance to Theta1 Orionis A as -1630.82 light years away from Earth or -500 parsecs. It would take a spaceship travelling at the speed of light, -1630.82 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.
The star's Galacto-Centric Distance is 7,920.00 Parsecs or 25,832.14 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.
|Flamsteed Name||41 Orionis|
|Flamsteed Short Name||41 Ori|
|Bayer Designation||Theta1 Orionis A|
|Hipparcos Library I.D.||26220|
|Henry Draper Designation||37020|
|Visual / Apparent Magnitude||4.98|
|Naked Eye Visible||Yes - Magnitudes|
|Right Ascension (R.A.)||05h 35m 15.82|
|Declination (Dec.)||-05 d 23 ` 14.3|
|Galactic Latitude||-19.39 degrees|
|Galactic Longitude||209.01 degrees|
|1997 Distance from Earth||-2.00 Parallax (milliarcseconds)|
|-1630.82 Light Years|
|Galacto-Centric Distance||25,832.14 Light Years / 7,920.00 Parsecs|
|Radial Velocity||28.30 ± 1.00 km/s|
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. Id||B.D. Id||Star Code||Magnitude||R.A.||Dec.||Spectrum||Colour||Year|