Crash of the Titans
NGC 520 — also known as Arp 157 — looks like a galaxy in the midst of exploding. In reality, it’s the exact opposite. Two enormous spiral galaxies are crashing into each other, melding and forming a new conglomerate. This happens slowly, over millions of years — the whole process started some 300 million years ago. The object, about 100 000 light-years across, is now in the middle stage of the merging process, as the two nuclei haven’t merged yet, but the two discs have. The merger features a tail of stars and a prominent dust lane. NGC 520 is one of the brightest interacting galaxies in the sky and lies in the direction of Pisces (the Fish), approximately 100 million light-years from Earth.
This image was taken by the ESO Faint Object Spectrograph and Camera attached to the 3.6-metre telescope at La Silla in Chile. It is based on data obtained through B, V, R and H-alpha filters.
Credit:
ESO
About the Image
| Id: | potw1048a |
| Type: | Observation |
| Release date: | 29 November 2010, 10:00 |
| Size: | 959 x 959 px |
About the Object
| Name: | Arp 157, NGC 520 |
| Type: | • Local Universe : Galaxy : Type : Interacting • Galaxies |
| Distance: | 100 million light years |
Coordinates
| Position (RA): | 1h 24m 34.75s |
| Position (Dec): | 3° 47' 30.00" |
| Field of view: | 5.04 x 5.04 arcminutes |
| Orientation: | North is 0.9° right of vertical |
Colours & filters
| Band | Wavelength | Telescope |
| Optical B |
445 nm | ESO 3.6-metre telescope EFOSC2 |
| Optical V |
551 nm | ESO 3.6-metre telescope EFOSC2 |
| Optical R |
658 nm | ESO 3.6-metre telescope EFOSC2 |
| Optical H-alpha |
1.63 μm | ESO 3.6-metre telescope EFOSC2 |



