Hubble Telescope Unveils Milky Way’s ‘Living Fossil’ Neighbor

Jenny Flack

The Hubble Space Telescope has discovered a previously undetected dwarf galaxy in the Milky Way’s backyard.  It’s a mere 30 million light-years away (the seeable universe is 93 billion light-years across!), and so old that scientists have deemed it a “living fossil” right in our neighborhood.  Space.com reported on Thursday. 

RELATED:  Can the Goblin Behind Pluto Lead Us to Planet 9?

The galaxy was found by accident, as so many things in space are.  Researchers were using Hubble to study white dwarves (super-dense “stellar corpses”) in the globular cluster NGC 6752.  NGC 6752 is in the Milky Way itself.  But as they were analyzing the images they got back, they realized that the stars they were looking at existed beyond NGC 6752.  Their brightness and temperature indicated that they, in fact, lay in another galaxy all together. 

This composite image shows the location of the accidentally discovered dwarf galaxy Bedin 1 behind the globular cluster NGC 6752. The lower image, depicting the complete cluster, is a ground-based observation from the Digitized Sky Survey 2. The upper right image shows the full field of view of the NASA/ESA Hubble Space Telescope. The upper left one highlights the part containing the galaxy Bedin 1.

Astronomers determined that this new galaxy is small.  Very small.  It is only 3,000 light-years wide.  By way of comparison, the Milky Way is 100,00 light-years wide across the diameter of its famous spiral disc.  Named Bedin 1, after the discovery team leader L. R. Bedin of the INAF-Osservatorio Astronomico di Padova in Italy, it is a “spheroidal dwarf”.   Many galaxies of its kind (more than 20) are known satellite galaxies around the Milky Way.  But this one is different.

RELATED:  Black Holes Could Reanimate Zombies 

Bedin 1 is 2 million light-years from any galaxy that might be its host (in this case, NGC 6744).  It’s unusually far.  That makes Bedin 1 the most isolated small dwarf galaxy known.  And it is very, very old.  In a statement, the Hubble team noted, “From the properties of its stars, astronomers were able to infer that the galaxy is around 13 billion years old — nearly as old as the universe itself,” and “Because of its isolation — which resulted in hardly any interaction with other galaxies — and its age, Bedin 1 is the astronomical equivalent of a living fossil from the early universe.”

Exciting, right!?! It’s like finding a dinosaur femur underneath your deck while you’re pulling weeds!  What will we learn next!?!  

The researchers published their findings online Jan. 31 in the journal Monthly Notices of the Royal Astronomical Society: Letters.

 

 

Jenny Flack
follow me!

Leave a Comment