May 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 May 24th. For May, your best viewing nights will be from May 14th through May 28th. The Star chart below is set for Florence, SC on May 15th at 10 pm.


ScienceSouth’s New Astronomy Program: The Sidewalk Astronomer

Update:  Our Sidewalk astronomy program continues each month. On April 25th at our Mad Scientist Gala at the ScienceSouth Pavilion we had our big Dob telescope out.  Everyone enjoyed the excellent view of Saturn, even though the rings are tipped toward us.  We also viewed the Beehive star cluster, and could clearly see that the naked eye double star in the Big Dipper’s handle (Mizar and Alcor) is really a triple star system.  Our Dob could easily split Mizar into Mizar A and B.  Please note that although the famous “double” star Mizar and Alcor has been known for centuries, it is not a true double star, because they do not orbit each other.  Mizar A and B however is a true double star system. 

As of this writing, we are planning to be at the Florence Civic Center late afternoon and early evening on May 7th at the Darlington Car Hauler Event. We will have our solar telescope and solar projection apparatus available. Other Sidewalk Astronomy events in May will be posted on our website.

The Planet Neptune:

Readers of this column are usually new amateur astronomers. As such, there are many targets that are a must see for new amateurs. One set of targets on any list is to see all the planets of our solar system. This is not an especially easy task for the new amateur. Some planets are easy to see, but others are not.  Venus, Jupiter, Saturn and Mars, are easy targets. Mercury is easily bright enough to see with the unaided eye, but as I explained in other columns, it can be difficult due to its proximity to the Sun. We had two good viewing positions in Dec 2008, and in April 2009, and there will be many more in the future. That leaves the two most distant planets, Uranus at about 1.7 billion miles, and Neptune at about 2.7 billion miles.  Both planets are difficult targets, and both will be visible late summer and into the fall. As you may recall, I do most of my personal viewing with large 100 mm binoculars usually at 25 power. At 25 power, I can see Uranus as a blue-green object. Neptune is also visible at 25 power, but looks star-like, and you have to use some “imagination” to see its blue color. Uranus is a little difficult to find this year because there are no bright “finder” stars near by to help out. At a billion miles farther away, Neptune is almost always a hard target for new amateurs. However, this year, Neptune has a good “finder” object near by; the planet Jupiter.

I seldom ask people to get up in the early morning for viewing before sunrise, but your best and easiest shot at finding Neptune is on May 25th about 5 am. On that date, the two planets will appear in the closest line of sight. Now, the 25th is a Monday, if you prefer to get up early on the 24th or 23rd, Neptune will be in a similar position, but slightly to the left. When Jupiter and Neptune are both evening targets in August and September, their larger separation will make it more difficult to locate Neptune. Of course once you become comfortable using star charts and computer programs, good “finder” objects will not be needed.  Below shows the position of Neptune versus Jupiter and a nearby star Mu Capricorni. The red circle represents the view through 25 power binoculars.  Don’t forget, that if you use your refracting telescope the image will be reversed right to left from what is shown below.  If you use a reflector it will be upside down versus what is shown below.

Finally, some interesting Neptune trivia. Neptune was the first planet to be predicted mathematically, before it was actually found. This was based on its gravitational effect on Uranus.  

Galileo actually saw and sketched Neptune on December 28, 1612, but thought it was a star. Galileo unfortunately viewed Neptune when it shows the least motion in the sky; right at the end of retrograde. Neptune was officially found in 1846 by Le Verrier. The image below is what Galileo saw in 1612.


The Messier pick for the month is M13, the Hercules cluster. With your binoculars, it will be a tiny fuzz ball. With small telescopes it will be a bigger fuzz ball. You will need a decent size reflector to resolve any of the stars as is shown below.

Its location below is shown for 10 pm May 15th, but of course it will be visible for the next several months.

Naked Eye Sights:  If you are a fan of planet watching, and are an earlier riser, there will be five planets in the eastern sky between 4 and 5 AM toward the end of May; Mars, Venus, and Jupiter will be naked eye objects, and Uranus and Neptune will be binocular or telescopic sights. 

Binocular Sights (7 to 10 power):  Try for Neptune with your binoculars.  Its position near Jupiter may make it a possible binocular target.  Continue your Messier list.  Try for M13, the Hercules Cluster.

Telescope Sights (60-100mm):  Try to see the most distant planet Neptune, and try to see its blue color. Don’t forget to look at the nearby Jupiter.

See you next month.

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