July 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 July 19th. For July, your best viewing nights will be from July 7th to the 23rd. The Star chart below is set for Florence, SC on July 15th at 10 pm.

Venus Transit:
The ScienceSouth team and over 130 visitors enjoyed perfect viewing for the June 5th Venus transit of the Sun outside our pavilion at Freedom Florence. Everyone was able to view the transit through our filtered 10-inch Dobsonian reflector, our H1 alpha solar scope, and on a projection screen using our Sun Spotter. We were also pleased to have Francis Marion University astronomy professor Dr. Jeanette Meyers join us. Dr. Myers brought an additional filtered 10-inch Dobsonian reflector, and also supplied everyone present with a pair of special solar viewing glasses. Visitors were told to keep these glasses in a safe place to be reused on August 21, 2017 for the total solar eclipse that will pass over central South Carolina.
The Summer Milky Way:
Each summer I remind everyone that this is a great time to be outside, hopefully at a dark sky site, scanning the summer Milky Way.  If we revisit our place in the Milky Way galaxy we see that we are about 2/3 out from the center. See image below:



As we revolve around the Sun and look out into the southern sky, in the summer we are facing into the center of the Milky Way, and in the winter, we are facing away from the center of the Milky Way. This timing of course is just a chance/random happening. Therefore in the summer, higher concentration of matter toward our galaxy’s center allows us to view more visible stars, nebulas, and star clusters.  Hopefully some of my readers have ready access to local sites where the Milky Way is visible. The only downside for our part of the country is that summer also brings humidity, which can interfere with viewing the night sky. 
If you are a serious amateur astronomer and have never seen a brilliant Milky Way, you should try to plan a vacation to a dark sky site. Many dark sky sites are in areas where other interesting sights are nearby for daytime excursions. Sometimes a dark sky site is so isolated that you have great nighttime viewing, and during the day you sleep late, barbeque, and make new friends with your fellow amateur astronomers. I used to drive 300 miles from New Jersey to an isolated dark sky site in the Allegeny Mountains of northern Pennsylvania, called Cherry Springs state park.  The image below shows the view of the Milky Way at Cherry Springs.


To find a dark sky site you can search the Internet, or look in the advertisement sections of Astronomy magazine, or Sky and Telescope magazine. One of many dark sky web pages is http://www.jshine.net/astronomy/dark_sky/. Below are some images from that site.


The blue “tear drops” are locations of private and public stargazing sites. Direct your attention to the dark blue viewing areas. Notice that the closest blue area to Florence is the Francis Marion National Forest, however, there are no sites there marked as astronomy viewing areas.  The closest good “blue” viewing area is in Georgia, called the Deerlick Astronomy Village, http://www.deerlickgroup.com/; check it out.
Another consideration is to look for dark sky sites near places where you have already planned a vacation. Finally, for the very serious amateur, you might want to plan a trip to Bolivia, South America next July for the Southern Skies Star Party;  http://www.astronomicaltours.net/SouthernSkies/. That is what you would call a true astronomy adventure! This Bolivia Star Party is still on my wish list.
However, it is time to return to Florence. Find the best local viewing site and direct your binoculars and telescopes toward the southern sky. The image below is centered on the constellation Sagittarius better known as the “Teapot” asterism. There are eleven Messier objects shown in this image, along with some NGC (New General Catalog) objects. Also note the location of the center of our Milky Way.



First scan this region with a pair of binoculars. Depending on the darkness of your viewing site, you should be able to spot several of the Messier (M) objects. Often you may only note that your target is too fuzzy to be a star. Certain objects in this image look well through a refracting telescope, such as M6 and M7. Most of the objects are best viewed through a reflector, such as a Dobsonian, or through “Big” binoculars. The most difficult Messier objects in this image are M20 and M21. Note, the Lagoon Nebula M8 is visible to the naked eye at Cherry Springs Park.
This other image is centered on the constellation Scorpius, and adds an additional four Messier objects.


Have you ever looked up at daytime clouds and saw shapes of animals or people? The “cloudy” Milky Way is really millions of stars seen at a distance. Actual clouds in the Milky Way are not white, but black and are made of dark matter blocking off the background stars. Now use your imagination and look for the “dark horse” cloud in the above three images of the Milky Way. If you have trouble locating it, see the image below.


Naked Eye Sights: The summer Milky Way
Binocular Sights (7 to 10 power): As always, continue looking for more Messier Objects to add to your list. In particular look toward the Milky Way’s center in the southern sky.
Telescope Sights (60-100mm): Use a reflector to scan the Sagittarius/Scorpius region.



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