Tiny, Hidden Galaxy Provides A Peek Into The Past

Tiny galaxy HIPASS J1131–31 peeks out from behind the glare of star TYC 7215-199-1, a Milky Way star positioned between Hubble and the galaxy. One hundred years ago, this fast-moving foreground star would have appeared directly in the line of sight, and the "Peekaboo" galaxy would not have been detectable at all.

With the resolution and sensitivity of the NASA/ESA Hubble Space Telescope, astronomers resolved 60 stars in the galaxy and were struck by the fact that they all appear to be relatively young—a few billion years old or younger. This is very unusual in the nearby universe, which has had about 13 billion years of cosmic history to develop. Peekaboo's stars indicate that it is one of the youngest and least-chemically-enriched galaxies ever detected in the local universe. The small galaxy presents astronomers with a unique opportunity for future in-depth analysis of a chemical environment typically only found in the very distant, early universe, where detailed study of individual stars' chemical makeup is not possible. Peekaboo is, in effect, a direct portal into the past, allowing us to discover what the universe was like near the dawn of time.

[Image Description: A large bright star is centered, with four long rays extending in an X shape. Between the rays on the right is a small blue peanut-shaped galaxy with some bright spots. Smaller similar stars and orange background galaxies fill image.]