June 2008

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 June 3rd. For June, your best viewing nights will be from June 1st through June 8th, and June 24th through June 30th.

The Star chart below is set for Florence, SC on June 15th at 9 pm.

I see June as a “quiet” observing month. While waiting for the arrival of some of the great targets of July and August in the region of, and above, Scorpius and Sagittarius, we can return to the Messier objects and locate some of the more difficult targets. In general, the Messiers are called DSO’s (deep sky objects), meaning that they are beyond our Solar system, and most of the Messier objects are within our Milky Way galaxy, the farthest being about 68,000 light years (globular cluster M75). However, a total of 40 Messier objects are truly deep sky objects, and are actually other galaxies well outside of the Milky Way. A total of seventeen of these galaxies are about 50 to 70 million light years away! Remember, our Milky Way galaxy is “only” 0.1 million light years across. Also remember that one light year is 6 trillion miles. If you have trouble conceiving these amazing distances, you are not alone. Where in our world a long drive is five to six hundred miles, and a long plane flight is three to five thousand miles, no one can really comprehend millions of light years.

It is interesting to note that although these distant Messier galaxies were discovered in the late 1700’s, it was not until the 1920’s that astronomers were shocked to realize that these fuzzy objects were outside of our galaxy. Edwin Hubble and Milton Humason discovered this fact while using special stars called Cepheid variables to determine star distance.

So it is time to try to locate some of these distant galaxies. First a note to any new amateur astronomers: Please don’t expect to see deep sky objects looking anything like a Hubble telescope image. Even if you have spent significant money on a telescope, the objects are often seen as white fuzzy objects. Only with expensive camera equipment and long time exposures using various filters can an amateur obtain beautiful and colorful images of deep sky objects.

Now, let’s try to find two relatively easy distant galaxies, M81 and M82 in the constellation of Ursa Major. M81 shown below is a bright grand design spiral galaxy filled with extensive new star birth. Grand design galaxies are those showing a “perfect” spiral structure. Only about ten percent of all known spiral galaxies have this designation. Although it was listed by Messier, M81 was originally discovered by Johann Bode, and is often referred to as “Bode’s Galaxy.”

M82, shown below, is dimmer than M81 and is also known as the “Cigar Galaxy,” which you will under stand from the photo. M82 is seen edge on, and has always been listed as an irregular galaxy. However, a recent observation in 2005 using infrared has detected some spiral arms. Also, observation with other large telescopes has shown that this galaxy is being deformed/pulled apart by gravitational forces from its larger neighbor M81.

M81 and M82 are both about 12 million light years away and are gravitationally linked.

So now let’s try to find them. Although I chose these galaxies because they are relatively bright objects, the downside is that they are sometimes hard to find because they are in a region that has no marker stars to help out. The good news is that being in the constellation of Ursa Major (home of the Big Dipper) they are circumpolar objects, therefore are visible all year long. However, they do get close to the horizon in August and September. Use a pair of binoculars to locate these galaxies, seven to ten power will be fine, and you will be able to see them both in the same field of view. This time of year, they are aligned in binoculars as is shown below, with M81 on the left. Of course, through binoculars, they will be tiny fuzzy objects, but you will still see their shapes.

Below is a star chart to help you out. Draw an imaginary line in the Big Dipper from Phecda to Dubhe, and extend the line out the same distance again. Be patient, keep away from city or neighborhood lights, and if you don’t have a steady hand, you may want to brace the binoculars against a tree, house, car, etc, or place you binoculars on a tripod. Good luck.

It is important to note that although the Messier objects contain 40 distant galaxies, there are at least 400-500 other non-Messier galaxies that are in range of large amateur telescopes. Therefore amateurs can busy themselves for many years searching for these “faint fuzzies.”

Naked Eye Sights:
Enjoy the rising of Scorpius in the south and Cygnus (the Northern Cross) rising in the east.

No major meteor showers are listed for this month. However, a lesser-known meteor shower is the Bootids. In recent years, there have been some outbursts of meteors reported for the Bootids. In June, Bootes is directly overhead, and the weather is warm, so lie down on a blanket or lounge chair on the night of June 26th, and hope for a good show.

Binocular Sights (7 to 10 power):
Your challenge this month is M81 and M82 as described above.

Telescope Sights (60-100mm):
Try for M81 and M82. Be sure to start at low power.

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