view of M104 under dark skies with the 82in
at the McDonald Observatory in West Texas
was simply wonderful. The best way to approach
M104 was from south of the nucleus, driving
the telescope north. With my eyes well dark
adapted, the halo was first sensed, quite
distant from the nucleus; then a dark band
entered the field of view followed by the
brilliant, almost stellar nucleus. At a magnification
of 900 times and a field of view of 6 arc
minutes, M104 filled the eyepiece. The nucleus
was seen as a brilliant light in a foggy bowl
surrounded by a dark band. I was able to measure
the visual nucleus - 2.8 by 1.6 arc seconds.
Visually the entire image was soft-foggy.
"Now in front of me I can see on this
Hubble image a very much smaller, but still
"boxy" nucleus at the center of
a thin disk. Dust is apparent at the nucleus.
To the south the dark band is filled with
a complex mixture of dust and starlight. The
spiral pattern can be traced throughout the
disk. Are we seeing brilliant blue stars in
the disk and along the dust lane? I believe
I can distinguish globular clusters embedded
in the halo. And what seems remarkable is
that distant galaxies can be seen shining
thru M104 right up to the edge of the disk.
This is a beautiful image of a great spiral."
The Distance Modulus
to the Sombrero galaxy can be calculated
using the following formula:
(where m = apparent magnitude,
M = absolute magnitude and
D = distance).
Using D = 8.8 Megaparsecs
and M =-10 or perhaps -5
m=19.7 and 24.7
"So it would seem we are seeing stars
(clusters?) scattered in the disk (especially
on the disk detail frame). What is the magnitude
limit? Globular clusters at M = -8 would be
at m = 21.7. I think I can identify some of
"I still marvel at the work and skill
it took to produce this image!"
An interpretation of the Hubble image from
a life-long Sombrero observer,
retired Indiana University astronomer, Martin
Burkhead, who was also a university professor
of Heritage team members Zolt Levay and Forrest