... In the lists below, "M numbers" refer to Charles Messier’s list of interesting ... 4. Twin-Jet Nebula (Minkowski 2-9) . What is It? . ? a planetary nebula . ... http://www.seds.org/messier/m/m001.html . http://chandra.harvard.edu/photo/0052/ . ...
... In the lists below, ?M numbers? refer to Charles MessierтАЩs list of interesting ... 4. Twin-Jet Nebula (Minkowski 2-9) . What is It? . тАФ a planetary nebula . ... http://www.seds.org/messier/m/m001.html . http://chandra.harvard.edu/photo/0052/ . ...