April 2012

Tony Martinez

Each month I will describe sights of interest in the night skies of South Carolina. These sights will be broken down into three sections; what you can see with the naked eye, with binoculars, and with a small telescope. The best time to view the night sky is at and around the times when the Moon is not visible, what is known as a New Moon; which will occur this month on April 21st. For April, your best viewing nights will be from April 11th to the 24th. The Star chart below is set for Florence, SC on April 15th at 9 pm.

Return to the Virgo Cluster:

Two years ago I gave a brief introduction to the Virgo Cluster. The Virgo Cluster is not a star cluster, but is a cluster of galaxies; the month of April is usually the best time to view this target. Data from the Hubble telescope estimates there are as many as 1500 galaxies associated with this cluster. This galaxy cluster is also referred to as the Virgo/Coma Bernice’s Cluster.

If you attempt to venture into this realm of galaxies, you are somewhat limited to using a reflecting telescope, preferably a 4 inch or larger Dobsonian, or large binoculars, such as 25 X 100 mm. A 100 mm binocular is actually the same size as a 4 inch telescope.However, dim objects such as galaxies are surprisingly more defined through the binoculars than with the equivalent telescope.

As always when attempting to find galaxies you must find a dark sky location. In our area of the country, five to ten miles outside of any modest size town should be sufficient for your search of the Virgo Cluster. A great viewing location is Lynches River Park. However, unless you are camping at the park, or coming to a Lynches River Star Party, you are not allowed to just bring your telescope to the park.The best choice may be to find a friend or relative who owns farm land.

Once you have chosen a good viewing location, first find the location of the Virgo Cluster, see circle below.

Next, check out the area circled with ten power binoculars. The image below is a good example of what you may see.

So where are the galaxies? With normal 7-10 power binoculars, this region looks like a simple star field. If you look carefully, you will note that several “stars” are somewhat larger and fuzzy. These small fuzzies are some of the many galaxies in the Virgo cluster. Next aim your reflecting telescope near the center of this region shown in the circle above. Starting at about 25 power, while looking through the eyepiece, slowly move your scope outward in an expanding spiral.Every few minutes check your telescope finder to make sure you have not drifted outside the Virgo Cluster region of the sky. This roaming technique is quite different from the normal careful searching for a specific target in the sky. If you have chosen a good dark sky site, and you are careful and patient, you should be able to see many small fuzzy galaxies. This next image is what you may see through your telescope. The yellow circle is the field of view at about 30 power.This image also shows the locations of various other cataloged galaxies. These objects are dimmer than the Messiers, and are assigned a NGC (New General Catalog) number.

The following image is how you could see the Virgo Cluster if you owned great astronomy equipment and used long exposure astrophotography.

What I have briefly described above is how to casually visit the Virgo Cluster of galaxies. If you are a serious Messier Object searcher, then you must revisit the Virgo cluster with more care. There are a total of fifteen Messier Objects near the center of the Virgo Cluster, and three others nearby. You will need a good star chart or computer program to start your search. Below is the star chart that I used to check off each Messier as I personally searched this region. As you can see, the chart lists Messiers, NGC objects and many too dim to be labeled objects in the Virgo region. I started with Messier 60 and ended with M49; logging fifteen Messiers in one April night’s viewing.

From M60 to M49, the black line/arrow shows the exact path I used that night as I worked my way through the cluster. I used 25 X 100 mm binoculars to locate all these objects.

Now it’s your turn.

Meteor Showers:

As you may remember there are only three major meteor showers each year, August, November and December. However, there are also minor showers. This year all three major showers occur on or near a new Moon; maximizing your viewing.

This month has a minor meteor shower called the Lyrids, and it also occurs during a new Moon. This shower peaks late at night on Sunday the 22nd, but you can also check on Saturday night. You may only see one meteor every 3-5 minutes, or as with any meteor shower we might get a surprise burst of meteors.

Remember, when viewing meteor showers; use only your eyes, no binoculars or scopes. Sit in a lounge chair to save you neck muscles.Look toward the region of the name of the shower; in this case, the constellation Lyra. In most cases, the best time to view is after midnight.

Naked Eye Sights: The brilliant Venus in the west. A red/orange Mars in the south and a yellow Saturn in the east. The only other bright object still in the sky this month is the star Sirius in the southwest.

The Lyrid meteor shower.

Binocular Sights (7 to 10 power): Follow the planet Venus April 1st through the 4th as it passes through the Pleiades Cluster (M45).

Telescope Sights (60-100mm:The Virgo Galaxy Cluster; see how many Messier Objects you can find in this region of the sky.

See you next month!

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