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
Distance:100 million light years
Constellation:Pisces
Category:Galaxies

Image Formats

Large JPEG
190.1 KB
Screensize JPEG
131.7 KB

Wallpapers

1024x768
159.3 KB
1280x1024
267.3 KB
1600x1200
399.9 KB
1920x1200
477.7 KB
2048x1536
637.2 KB

Coordinates

Position (RA):1 24 34.75
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

BandWavelengthTelescope
Optical
B
445 nmESO 3.6-metre telescope
EFOSC2
Optical
V
551 nmESO 3.6-metre telescope
EFOSC2
Optical
H-alpha
1.63 μmESO 3.6-metre telescope
EFOSC2
Optical
R
658 nmESO 3.6-metre telescope
EFOSC2