Universe Guide

Sirius B (Companion Star) Facts

Sirius B Facts

  • Sirius B is a dwarf star that can be located in the constellation of Canis Major. The description is based on the spectral class.
  • Sirius B is not part of the constellation outline but is within the borders of the constellation.
  • Based on the spectral type (DA2) of the star, the star's colour is white.
  • The star can not be seen by the naked eye, you need a telescope to see it.

Sirius B's Alternative Names

(Alpha Canis Majoris B) is the Bayer Classification for the star. The Bayer Classification was created by Johann Bayer in 1603. The brightest star in the constellation is normally given the Alpha designation, there are exceptions such as Pollux which is Beta Geminorum.

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

Location of Sirius B

The location of the dwarf 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 Sirius B, the location is 06h 45m 09.0 and -16 ° 43` 06 .

Physical Properties of Sirius B

Sirius B Temperature and Colour

Based on the star's spectral type of DA2 , Sirius B's colour and type is white dwarf star. Based on the star's spectral, the stars temperature is between 0.00 and 0.00 degrees kelvin.

Sirius B Mass

The Sirius B's solar mass is 0.98 times that of our star, the Sun. The Sun's Mass is 1,989,100,000,000,000,000,000 billion kg. which to calculate using this website is too large. To give idea of size, the Sun is 99.86% the mass of the solar system.

Sirius B Apparent and Absolute Magnitudes

Sirius B has an apparent magnitude of 8.44 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. 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 Sirius B

Sirius B is an estimated 8.60 light years from our Solar System (Earth and Sun). It would take a spaceship 8.60 years travelling at the speed of light to get there. We don't have a space ship that can travel that distance or at that speed yet.

Hide Explanations
Show GridLines

Additional Sirius B Facts and Figures

Visual Facts

Primary / Proper / Traditional Name Sirius B
Alternative NamesAlpha Canis Majoris B
Spectral TypeDA2
Constellation's Main StarNo
Multiple Star SystemYes
Star TypeDwarf Star
GalaxyMilky Way
ConstellationCanis Major
Visual / Apparent Magnitude8.44
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)06h 45m 09.0
Declination (Dec.)-16 ° 43` 06
Distance from the Sun / Earth8.60 Light Years
Associated / Clustered StarsSirius
Sirius A

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Estimated Calculated Facts

Calculated Temperature Range0.00 - 0.00
Mass Compared to the Sun0.98

Location of Sirius B in Canis Major

Sirius B Location in Canis Major

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.


ConfusedThursday, 26th September 2019 7:50:53 PM
What is Sirius B´s absolute magnitude?
This website is using cookies. More info. That's Fine