April 2010

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 14th. For April, your best viewing nights will be from April 1st through April 19th. The Star chart below is set for Florence, SC on April 15th at 9 pm.

The Dance of the Planets:

This term has often been used to describe the movement of the planets through the stars, and also to the movement of the planets in relationship to each other.

As you know, there are five planets readily visible to the naked eye; four of these five planets are visible in the evening this month.

We can start with an interesting “Dance of the Planets” by viewing Venus and Mercury. Venus returns this month as the “Evening Star.” The interesting “Dance” I am referring to begins on April 1st right after sunset. The bright Venus will appear in the west, and the fainter planet Mercury will appear slightly below and to the right of Venus. If the weather allows, try to watch them every evening. You will notice that they both seem to be rising higher together. From the 1st to the 5th, Mercury looks like it is catching up to Venus. Then from the 5th to the 9th, they seem to be traveling together as they both move higher in the sky. It isn’t until the 10th onward that Venus pulls ahead, and near the end of the month Mercury is lost from view. Note on April 16th, you can see Mercury, Venus, and the thin crescent Moon just after sunset.

The planet Saturn is bright all month and easily visible in the southeast to south. Saturn is the favorite planet for anyone with a telescope, but the rings still remain just barely tipped toward us. The good news is that Saturn’s rings are tipping more towards us, so we can look forward to an increasingly better view over the next several years.

The last of the four visible evening planets this month is Mars. It will shine brightly in the south/southwest throughout the month, to the right of Leo the Lion. I suggest you take time to view Mars in mid-month because of its location in the sky. On April 15th through the 18th, Mars passes by the open star cluster M44, also known as the Beehive Cluster. I have mentioned the Beehive in earlier columns; see below.

This cluster contains about 1000 stars, but only about 30-40 stars are visible through binoculars or a small telescope. It is always fun to try to see this cluster with the naked eye. It should be easy to see on any clear night away from city lights, and this month you can use Mars as a marker to find the Beehive cluster.

The Virgo Cluster:

Springtime gives us the best view of the Virgo Cluster. When one usually mentions clusters, they mean clusters of stars. However, the Virgo Cluster is a cluster of galaxies! 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 Berenices Cluster. Note in the image below is only a small section of this cluster; every smudge is another galaxy, some like our Milky Way.

As we all know, nothing in our meager amateur scopes compares to Hubble images. If you have a large amateur scope, your best view of the Virgo Cluster may be as shown below.

More likely, views from amateur equipment will show only faint smudges. So why bother? In this column I consistently repeat that the best way to learn the night sky is to try to locate all of the Messier Objects, 109 or 110, depending on whose list you use. So why the Virgo Cluster? A minimum of 16 Messier Objects are located in this cluster, more depending on how you define the limit of this cluster. The location of this galaxy cluster is easy to find because it is right behind the tail of the prominent spring constellation Leo the Lion. The circle on the chart below defines the center of the cluster.

Observation techniques: Whenever your targets are galaxies, you must first find a dark sky site. Make sure you wait for your eyes to become totally dark-adapted; this could take from 5 minutes for the younger observers to 20 minutes for the older crowd. Once adapted, use only dim red lights to work with your charts or other equipment. As I mentioned, some of the galaxies will be visible through binoculars; remember they will be only faint smudges. I have personally easily located 16 Messiers in the center of this cluster by using very large binoculars 25 X 100 mm. Good luck in your search.

Naked Eye Sights: The brilliant planet Venus returns as the “Evening Star” in the west just after sunset. Look for Mercury as is joins Venus rising above the horizon. Using Mars as a guidepost, try to spot the open star cluster M44 (The Beehive) in mid month. If you wish to observe the fifth naked eye planet, you will find Jupiter in the east just before sunrise towards the end of the month.

Binocular Sights (7 to 10 power): Check out Mars passing by the Beehive Cluster in mid month. Try to locate some of the tiny smudges in the Virgo Galaxy Cluster.

Telescope Sights (60-100mm): Wander through the Virgo Galaxy Cluster. If you only own a small refractor, it would be best to revert to binoculars. Most reflectors, such as Dobsonians should allow you to spot many Messiers in this cluster.

See you next month!

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