Looking Up: The Young And The Restless

Aug 19, 2019

File:Sidney Hall - Urania's Mirror - Pisces. This image is available from the United States Library of Congress's Prints and Photographs division under the digital ID cph.3g10073
Credit Restoration by Adam Cuerden / U.S. Public Domain

This week on Looking Up we learn about a lonely star passing through our galaxy.

I’m going to talk extra fast today to tell you about an extra-fast star in the Colorado sky right now, Gamma Piscium, the second brightest star in Pisces the fish.

GP, as I will call it today, is interesting as a star because it’s a relatively young star, at only 1.4 B years old, but it is also racing through its nuclear fuel. But that’s not what makes GP so interesting. What makes this star so unusual is how it is moving through space. GP is approaching our solar system at about 31,000 mph. That is quick, but not especially quick. But when you measure GP’s movement laterally, that is, across the sky, we find that it is truly zooming along at a speed of over 325,000 mph. It also is very low in heavy metals and it doesn’t seem to have any companion stars.

All that leads astronomers to hypothesize that GP is not from around here. Indeed, it is possible that GP comes from an entirely other section of the Milky Way galaxy, or perhaps even outside the Milky Way. So take a look at Gamma Piscium and wave goodbye to this visitor to our section of the Galaxy, because in a few million years, it will be long gone.

If you’d like to take a closer look at Gamma Piscium, or any of the other wonderful and amazing things in the sky, please visit csastro.org for a link to information on our monthly meetings and our free public star parties.