A cloud of ionized gas emitting light of various colors, often found in regions of active star formation and contributing to the reddish hues observed in galaxies.
Source: esa.int

15/04/2008

27/03/2008

07/03/2008

04/03/2008

21/02/2008

14/01/2008

24/12/2007

09/11/2007

19/10/2007

18/10/2007

30/09/2007

11/09/2007

22/08/2007

04/08/2007

11/05/2007

18/04/2007

12/04/2007

21/03/2007

28/02/2007

14/02/2007

30/01/2007

11/01/2007

04/01/2007

19/12/2006

30/11/2006

20/10/2006

03/10/2006

24/09/2006

22/09/2006

16/08/2006