LCAS Observer Challenge - March 2005
Dave Wagner
Spring is on its way! Winter's sign-post, Orion, is sinking with Gemini towards the western horizon, and Leo and Virgo are rising in the east.
For the March/April Observer Challenge, many of the Messier objects are 'Virgo-centric', and that means... galaxies! The Virgo Cluster, an 'irregular' rich cluster of galaxies containing a variety of diff-erent galaxy types, provides a window to our local supercluster of galaxies. This Virgo Cluster is so massive that our own Local Group of galaxies is affected by its gravity.
With the propensity of galaxies in this challenge group, perhaps some sug-gestions for observing them are in order. Don't expect to see the same views as you see in photos from Hubble, but with a little patience and technique your viewing will be rewarding.
The listed visual magnitude for a galaxy represents the total light emitted from the galaxy. Since galaxies are significantly larger in area than a star or compact cluster, they will 'appear' much dimmer than you might expect for the listed magnitude. You'll need a dark site and well adapted night vision to find and to pull any details from your observations.
Start at low magnification. This will both aid in putting as much light as possible into your eye and aid in initially locating your targets. Higher magnification can sometimes help by balancing the light input with the size and contrast of the object, but it is mainly used when the object has been located to try and draw additional detail from your observation. The particular galaxy and environment (light pollution, transparency and seeing) will determine the effectiveness of higher power. Give it a try. In the case of M104 pictured below, higher power will be very useful to fully appreciate the central dust lanes and galactic bulge.
Use of averted vision to allow the light to fall on the more light sensitive portion of your eye will help to pull more detail from your observation, or in some cases to even spot your target. Some articles on observing faint deep sky objects have suggested tapping gently on the scope to cause a slight movement of the field of view to bring out the image. Give it a try.
See how much detail you can tease out of your observations. Just remember that you'll need dark skies, good dark ad-aptation and sound technique to find most of the challenge objects for this March / April block.
