Astronomy Picture of the Day

Explanation: Enigmatic spiral galaxy NGC 1097 lies about 45 million light-years away in the southern constellation Fornax. The small companion galaxy, just below and left of centre, that seems to be wrapped in its spiral arms, is not NGC 1097's most peculiar feature though. Instead, This very deep exposure shows hints of faint, mysterious jets, most easily seen to extend well beyond the bright arms toward the lower right. In fact, four faint jets are ultimately recognized in optical images of NGC 1097. The jets trace an X centred on the galaxy's nucleus, but could be fossil trails left over from the capture of a much smaller galaxy in the large spiral's ancient past. A Seyfert galaxy, NGC 1097's nucleus also harbours a massive black hole.