M104 – The Sombrero Galaxy
June 3, 2008
Striking in photographs, the Sombrero galaxy offers a fine example of an edge-on spiral. Is your scope up to the challenge of revealing the dark dust lane that gives this galaxy its Mexican hat-like appearance?
The Basics
• This is a lovely object, a little like NGC4565 but with a huge and brilliant central bulge, likely caused by the machinations of a massive black hole in the center
• At magnitude 9.0, the Sombrero Galaxy is located 11.5° west of Spica and 5.5° northeast of Eta Corvi at RA 12h39m59s and Dec -11d37m.
• Messier added this object in a handwritten note on his original list of 103 non-stellar objects. But it was not officially included in his famous list until 1921.

M104… Note the unusually bright galactic nucleus
A Deeper Look
• M104 was the first galaxy in which rotational motion was measured. By looking at the differing redshifts of stars at each edge of the galaxy, it was shown that one edge turns towards us and another turns away.
• Recently, satellite observations show the dust lane to be a symmetric ring of gas and dust around the bulge.
Good To Know
Less than 100 years ago, many astronomers argued that galaxies were simply gas clouds inside our Milky Way. But at Lowell Observatory in 1912, Vesto Slipher made the astonishing discovery that the Sombrero was hurtling away from Earth at 700 miles per second, faster than anything in our galaxy. This supported the view that these “nebulae” were outside our own galaxy, a view confirmed in 1923 when the distance to the Andromeda galaxy was determined.
Personal View
This one’s well worth a look, though you’ll need at least an 8-10″ scope to see the striking dust lane. M104 sits in a lovely field of stars that includes the multiple star Sigma 1664.



