More Great Views during 100 Hours of Astronomy

Remember that contest to select HST’s next imaging target?  Well, the image has been taken and posted to celebrate 100 Hours of Astronomy and IYA.  HST imaged the winner — Arp 274, set of galaxies jsut beginning to interact with each other.  HST’s view, which was taken on April 1-2 (just the last two days!) is here. It’s a stunner!

Arp 274, also known as NGC 5679, is really a system of three galaxies. They’re probably at different distances from us and each other, but from our point of view here on Earth, they appear to be overlapping.  You can make out spiral shapes in two of the galaxies, although upon closer examination, there’s some distortion going on due to the merger activity. As we might expect from galaxies that are undergoing (or have undergone) a merger, there’s a lot of star formation going on. It’s triggered by the interaction of the galaxies as shock waves slam star-forming regions and jump-starting the stellar birth process. The starbirth regions are strong along the arms of the spirals and in the small blobby-looking galaxy to the left. .

The largest component is located in the middle of the three. It appears as a spiral galaxy, which may be barred. The entire system resides at about 400 million light-years away from Earth in the constellation Virgo.

Astronomers used Hubble’s Wide Field Planetary Camera 2 to image this striking galaxy triplet. Blue, visible, and infrared filters were combined with a filter that isolates hydrogen emission. The colors in this image reflect the intrinsic color of the different stellar populations that make up the galaxies. Yellowish older stars can be seen in the central bulge of each galaxy. A bright central cluster of stars pinpoint each nucleus. Younger blue stars trace the spiral arms, along with pinkish nebulae that are illuminated by new star formation. Interstellar dust is silhouetted against the starry population. The pair of foreground stars at the far righth are inside our own Milky Way Galaxy.