Universe Guide

BI Cygni

BI Cygni Facts

Location of BI Cygni

The location of the supergiant 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 BI Cygni, the location is 20 21 21.8871531507 and +36 55 55.725144903 .

Radial Velocity and Proper Motion of BI Cygni

Proper Motion

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 -5.22 milliarcseconds/year towards the north and -2.93 milliarcseconds/year east if we saw them in the horizon.

Radial Velocity

The Radial Velocity, that is the speed at which the star is moving away/towards the Sun is -6.82 km/s . 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 (Colour) of BI Cygni

BI Cygni Colour and Temperature

BI Cygni has a spectral type of M4Iab. This means the star is a red supergiant star.

Distance to BI Cygni

The Parallax of the star is given as 0.73 which gives a calculated distance to BI Cygni of 4487.05 light years from the Earth or 1375.71 parsecs. It would take a spaceship travelling at the speed of light, 4487.05 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

The star is roughly 283,758,579.34 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.

Hide Explanations
Show GridLines

Additional BI Cygni Facts and Figures

Visual Facts

Primary / Proper / Traditional NameBI Cygni
Spectral TypeM4Iab
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star Type very luminous Supergiant Star
GalaxyMilky Way
Right Ascension (R.A.)20 21 21.8871531507
Declination (Dec.)+36 55 55.725144903
Distance from Earth0.73 Parallax (milliarcseconds)
 4487.05 Light Years
 1375.71 Parsecs
 283,758,579.34 Astronomical Units
Proper Motion Dec.-5.22 milliarcseconds/year
Proper Motion RA.-2.93 milliarcseconds/year
Radial Velocity-6.82 km/s

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Sources and Links


Location of BI Cygni in Cygnus

BI Cygni Location in Cygnus

The map was generated using Night Vision, an awesome free application by Brian Simpson.

Related Stars

Comments and Questions

There's no register feature and no need to give an email address if you don't need to. All messages will be reviewed before being displayed. Comments may be merged or altered slightly such as if an email address is given in the main body of the comment.

You can decline to give a name which if that is the case, the comment will be attributed to a random star. A name is preferred even if its a random made up one by yourself.

This website is using cookies. More info. That's Fine