Tuesday, 15 March 2016

Leo's bearing triplets!

I'm sorry for all of you who believe that Leo's a magnificent male lion because in reality she's a lioness. In fact, a pregnant one too because she's bearing triplets in her belly! What you see on my sketch is a group of three galaxies, about 36 million lightyears away. M66 is the most prominent one (bottom). It's more or less the size of our own galaxy but it's much heavier. That's because at some point in the past (we guess about 800 million years ago) it had a close interaction with NGC3628 (top left), the result of which is that it has an extreme central mass concentration and an unusually long, sweeping spiral arm which is barely visible here. 

NGC3628's also known as the "Hamburger Galaxy". With my binoculars it was again almost impossible to make out, but this galaxy features a very large and prominent dust lane all along its length, making it look like a hamburger squeezed between the two parts of a bun. When viewed through larger instruments this galaxy rather resembles a bone, with large clouds sticking out at both edges. These clouds consist of stars and gas and are also the result of its encounter with M66. Gravitational forces were so strong that they literally tore the galaxy's gas out, leaving the galaxy itself completely deformed. 

M65 (centre right) is the least interesting of the three. Star formation in it seems to be very low and therefore it has a very high ratio of older stars, although a recent burst of new star formation suggests that it may have had  a close interaction with the other two as well. 

Although a pair of binoculars are not the ideal instrument to observe distant galaxies, this trio truly deserved the visit because they were sitting so nicely within the large field of view. And in the end I was happy that I managed to make out more detail than I originally anticipated.

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