Salutations celestial sight seers!
I'm David Fuller, welcome to Eyes on the Sky; what's up this week?
South of Melotte 111 is the Virgo Cluster of galaxies.
Our own Local Group of galaxies, including the Andromeda galaxy, are part of the Virgo
Supercluster.
But within the visual boundaries of Virgo, is a galaxy that is.... well, not part of
that cluster.
In fact, astronomers aren't entirely sure if it is part of a cluster or group of galaxies
at all.
Maybe it's the hat?
Of course, I'm talking about the Sombrero Galaxy.
The thin, dark dust lane, and the 6 degree tilt which serves to give it that distinctive
�Sombrero� appearance are it's easily identified features.
The nearly edge-on orientation provides some additional surface brightness to enhance our
ability to view it.
So where to find it?
Also known as Messier 104, it is located just barely inside the boundary of Virgo, near
the constellation Corvus.
Look for Saturn and Spica in the south about 3 hours after sunset. 15 to 20 degrees
southwest of Virgo is a quadrilateral shape of mostly 2-nd magnitude stars.
On the northeast side is the 2.9 magnitude star Algorab, which in Arabic means �the
raven�.
Less than a degree from Algorab is 4.3 magnitude Eta Corvi, which may require
a magnified finder or binoculars to see.
3.4 magnitude Porrima in Virgo also may be visible naked-eye, that being the direction
we are heading.
Dark Sky Fact: The International Dark Sky Association recently announced the U.S. based
home improvement store Lowes carries dark sky friendly lighting in stores.
If you have a Lowes near you, stop in and either find their display or look for
these fixtures on the shelves.
Look for this triangle of stars in a finderscope or binoculars.
These are only three degrees away, so you should easily have Algorab and these three
stars in the same finder field of view.
Before reaching the galaxy, look closely at this 6.4 magnitude
star with a faint 9.6 mag secondary that is difficult-to-split 3 arc seconds away.
We'll use that star, along with this 5.6 magnitude one, to point towards the
Sombrero.
But one more stop; check out this set of fours stars just off our line of movement � although
physically unrelated to each other, this line-of-sight grouping of 6-th through 8-th magnitude stars
still looks pleasing in the eyepiece.
M104 is on a nearly straight line from our double through the 5.6 magnitude star, and
that foursome of stars is about halfway from the apex of the triangle to the galaxy, so
use it as a midpoint.
Just don't let the four stars let your scope drift off
line; center -this- area in the crosshairs of the finderscope.
Start with a low to medium focal length eyepiece, and see if you can spot the faint, spindle-shaped
glow of Messier 104.
Under very dark skies, this is possible with a 60 millimeter scope, but with light pollution,
120 millimeters or more of aperture may be needed.
To really see the dark dust lane, eight inches or more of aperture likely will be
required.
If the galaxy proves elusive, as a consolation look for these two 5.9 magnitude stars just
1.4 degrees away.
Use high magnification, as they are a close 5 arc seconds apart.
Observing tip: Using greater magnification on dim objects like galaxies can help to darken
the sky background.
Although this does not actually change the contrast, it is easier to see a somewhat larger
faint grey smudge on a black background than a smaller
faint grey smudge on a grey background.
Use as much magnification as your telescope will support.
Along The Ecliptic: On May 11, look for Jupiter, the Moon and Venus in the western sky just
after sunset.
At just a few days old, the Moon will likely require binoculars, but the brilliant Venus
may pop out of twilight just before setting.
And Saturn largely rules the sky all night long having reached opposition last week.
That's all for this week.
Keep your eyes on the sky and your outdoor lights aimed down, so we can all see, what's
up.
I'm David Fuller, wishing you clear and dark skies.