Holy Wow, what a beauty! This is NGC 7090, a spiral galaxy seen nearly edge-on, which means we cannot directly see the arrangement of its spiral arms. When we look at spiral galaxies, we typically see these hot blue stars in the spiral arms.
But NGC 7090 is really actively hatching new stars, and we can see them clearly in the pink patches that dot the galaxy. Those pink regions are cooler clouds of hydrogen gas, inside of which stars are forming. Also, those pink clouds are … pink which means they’re warm enough to be illuminated by recently formed hot stars within.
There is a lot of dust seen in silhouette against the bright core of the galaxy way behind in the distance. It’s not unlike looking at the center of our own Milky Way – the best we can do is look towards the center because of all of the intervening gas and dust that absorbs visible light. To see any beter we must turn to infrared and radio.
Of course, Hubble has a rather narrow field of view compared to other telescopes. With a decent ground-based image, you can get the entire galaxy in the field of view, and that’s what amateur astronomer Steve Crouch did in his magnificent image of NGC 7090. Below is Steve’s image, rotated to roughly line up with the Hubble image:
BTW, NGC 7090 is located about thirty million light-years from the Sun in the southern constellation of Indus.
See NASA’s writeup of NGC 7090 for more info.
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