Proxima Centauri

Hubble's look at Proxima Centauri. Credit: ESA/NASA/Hubble via Spaceref

Hubble’s look at Proxima Centauri. Credit: ESA/NASA/Hubble via Spaceref

A nice Hubble image of Proxima Centauri. It is the closest star to us at (about) 1.3 pc / 4.24 light-years in the constellation of Centaurus.

You would think Proxima Centauri, being so close would be easy to see but not so. Proxima Centuri is a red dwarf that is much too dim to see with the naked eye at a magnitude 11.05 – most of the time. This star is also called a flare star, a star can undergo dramatic increases in brightness.

The brightness increases because of changes in the magnetic fields created by convection throughout the star and this results in an increased X-ray emission pretty similar to our sun. We must keep in mind Proxima Centauri is a dwarf star and while it has a density 40 times that of our sun, it has a much lower mass, around one eighth. What this star lacks in physical stature it more than will make up for in longevity, it is expected to shine for nearly a trillion years.

Proxima Centauri was discovered by Robert Innes, a Scottish astronomer who was the Director of the Union Observatory in South Africa. It turns out the star is part of a triple star system and you are no doubt familiar with two more well known members: Centauri A and B.