July 2009

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 July 21. For July, your best viewing nights will be from July 14 through July 28. The Star chart below is set for Florence, SC on July 15 at 10 pm.

ScienceSouth’s New Astronomy Program! The Sidewalk Astronomer      

Update:  Our Sidewalk astronomy program continues each month.  In June we were at St. Anthony Church, for lunar observing. The Moon was a waxing gibbous, and we had great views of the crater rims and the mountain ranges. 

On June 20, we were at Lynches River Park with our big Dob, and my personal 25 X 100 binoculars.  Although there were no significant clouds, the viewing was poor due to the high humidity. There was a brief clear spell at about 10 pm, which allowed us to resolve some of the stars in the Hercules Cluster (M13), and just barely resolve the Ring Nebula (M57). 

We will continue to venture out around the Florence area, but the summer humidity may limit us to the Moon and the planets until autumn. 

Summer Viewing:

As mentioned above, it is nice to be out stargazing on a warm summer night, but the humidity sometimes prevents clear viewing.  Remember that the sky sometimes clears right after a strong rainstorm, so look outside to check this out after the next rain.  Remember also some of the indicators of good sky viewing, such as the stars of the Little Dipper.

On a poor viewing night, you will only see three stars in the Little Dipper, Polaris, Kochab, and Pherkad.  If you can see more than these three, especially all seven, then the skies are good for viewing.  Of course any night that you can see the Milky Way is a great night for stargazing.

Except for the potential summer humidity problems, summer always gives us a great opportunity because we are looking toward the center of our galaxy when we look to the south.  This region is filled with a mixture of nebulae and star clusters.  The image below is much more than you can hope for in our local viewing location.

Each summer I will remind you to wander with your binoculars through the summer Milky Way, above Sagittarius and Scorpius.  Look for the many fuzzy objects in the region, knowing that each is either a nebula or star cluster.  If these fuzzies intrigue you, then bring out your telescope for a better view. 

Messier Perspective:

If you love amateur astronomy, then you enjoy searching out the many deep sky objects (DSO’s).  As you work through your Messier list, you may enjoy having a better perspective of exactly where are these objects.  If you have ever wondered about this, there is a simple freeware program that you can download which will show you where the Messiers are located, in and out of our galaxy.  The program is called “Where is M13?”  This freeware is available at http://www.thinkastronomy.com/.  The program is small, simple/intuitive, and user friendly.  Below is a screen shot of the program, showing the Galactic View locations of M13, M57 (the Ring Nebula), and the directions to the Andromeda and Sombrero Galaxies. If you switch to Galactic Map, you will see the locations of the Messiers as are shown on standard star charts. Check this program out!

The Summer Triangle:

The Summer Triangle asterism has risen; formed by the stars Deneb, Vega and Altair, as shown in the image below. This simple, but well known asterism rises almost exactly on the summer solstice each year; however, you can continue to see this triangle of three bright stars until it sets in mid to late December. 

Here are four fun targets in or near the Summer Triangle.

First, and the only one visible to the naked eye, the star Albireo.  I have mentioned this star in previous columns, but it is a target that one always revisits on any clear night.  Albireo is in the constellation of Cygnus the Swan, and would represent the head of the swan, or the foot of the Northern Cross asterism.  What makes this star so special is that it is a colorful double star with one having a deep blue color and its companion a yellow/gold color; quite striking through any telescope.

The second target is the Coat Hanger asterism, located in the constellation Vulpecula. This upside down coat hanger is best viewed with a simple pair of binoculars, check it out.

The third target is the Dumbell Nebula (M27) visible with binoculars, and with a reflecting telescope.  This remnant of a dead star is in a class called planetary nebulas.  On a clear night with a good pair of binoculars, M27 gives a 3D optical illusion of standing out in front of the background stars.

The fourth target is just slightly outside the Summer Triangle, the Ring Nebula (M57), and is a favorite target for telescopes that can handle 50 to 100 power. This is also a planetary nebula.

The cluttered image below will help you locate the above targets.

Naked Eye Sights:  Look toward the south, and hope for skies clear enough to see the Milky Way.  Locate the Summer Triangle.

Binocular Sights (7 to 10 power):  Wander through the region above Sagittarius, and to the left of Scorpius, to view a very rich star field.  Check out the Coat Hanger asterism, and the Dumbbell Nebula.

Telescope Sights (60-100mm):   If available, use a small Dobsonian to view the clusters and nebulae of the summer Milky Way.  Also locate the Ring Nebula, M57.

See you next month!

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