May 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 May 20th.  For May, your best viewing nights will be from May 8thto the 25th. The Star chart below is set for Florence, SC on May 15that 9 pm.

The rings of Saturn are finally back in view. The ring position of Saturn will continue to improve every year, and then return to the position you see it this month in about 2021. If you bought a telescope in the last few years, this is the time to take it out. You will be rewarded with excellent Saturn viewing now and for the next nine years. This year, Saturn will be in visible in the night sky after 9:30 pm in early May, and will continue through the end of July. The image below shows the ring positions over a 28 year period.

As you know, Saturn is the favorite planetary target because of its spectacular ring system. Over the years as Saturn tilts in relation to us, we see the rings at different angles. When the viewing angle is at or near zero degrees, the beautiful ring system fades from view; this occurred during 2009 and 2010. 
As amateur astronomers, we regularly view the planets in our solar system. As we point our telescopes into the night sky, the big ball of Jupiter looks quite nice, and the small fuzzy ball of Mars is OK, you can also detect the bluish-green colors of Uranus and Neptune, and some people even enjoy the very fuzzy crescent of Venus; but Saturn is special. You can view hundreds of images of Saturn on the Internet, but there is something magical when your see it through your own eyes. So if you have a telescope, Saturn is a must view beginning this month.
To find Saturn this month, look to the southeast to find the pale yellow planet. If you are in doubt about its location, then turn your eyes to the north. Find the Big Dipper, and then follow the handle of the dipper to “arc to the star Arcturus.” Arcturus will be the brightest object in the east. If you continue the curve from the dipper’s handle, you would normally come to another bright star, Spica. However, now instead of one star, you will see a “pair of eyes!” The “eye” on your right is the star Spica, and the “eye” to your left is Saturn. So this year it is quite easy to locate the position of Saturn. If you have dark skies, you should be able to see the contrast of the blue star Spica with the yellow planet Saturn. The image below shows the position of Saturn in relation to Arcturus and Spica in mid-April; note the Big Dipper in the upper left hand corner.

So what should you expect to see? With standard 7 (or 10) X 50 binoculars, Saturn will still look like a star. With 15 power binoculars (tripod needed) it will look like the star has “ears.” I regularly use 25 X 100 mm binoculars, and the rings of Saturn are then clearly visible. Therefore, any scope you use from 25 power on up will allow you to see the rings of Saturn. Most planets supply a significant amount of light to your telescope, and this should be a positive feature. However, with some simple telescopes, the contrast between the dark night sky and the bright planet can sometimes overpower you lenses. If you have any trouble clearly seeing Saturn’s rings with your telescope, try this simple trick. Try viewing Saturn after sunset, but before it becomes really dark. Now you will see the planet without the sharp contrast with the dark sky. Below are three views of Saturn that are likely with amateur telescopes. The smaller blurry image represents what you might see with a very inexpensive discount store telescope (best to avoid). The other two images represent views from Dobsonian reflectors ranging from 6 to 8 inches. The bottom line is if you own any telescope, you can see the rings of Saturn.

Venus Transit:

Time to prepare for the Venus transit next month; June 5th. A Venus transit is the rare alignment of the planet Venus with the Sun. During a transit using solar viewing equipment one can see Venus passing across the Sun as a small disk. This event will not occur again until the year 2117. I will discuss the Venus transit in more detail next month, but because it occurs early in the month, I wanted to alert my readers of the event. 

To safely observe this rare event requires special solar viewing equipment. Locally we hope to have public viewings at Francis Marion University and at our ScienceSouth pavilion at Freedom Florence.  Although it is on Tuesday, the transit of the Sun will start about 6:20 in the evening, and can be observed through to sunset. The total transit lasts about six hours, but we can only view it for about two hours on the east coast of the United States.
Naked Eye Sights:  The brilliant Venus slowly sets in the west throughout this month; on the 22ndyou will see a nice pairing of Venus with the crescent Moon. The red/orange Mars will still be visible in the south all month, and of course, the yellow Saturn in the east. 
Binocular Sights (7 to 10 power): As always, continue working on finding more Messier Objects to add to your list.
Telescope Sights (60-100mm: After several years, Saturn returns as your best target throughout May and June.

See you next month!

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