June 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 June 22nd.  For June, your best viewing nights will be from June 16th through June 30th. The Star chart below is set for Florence, SC on June 15th at 10 pm.

ScienceSouth’s New Astronomy Program: The Sidewalk Astronomer

Update:  Our Sidewalk astronomy program continues each month.  On May 7th we were at the Truck Hauling Event at the Florence Civic Center late afternoon and early evening with our solar telescope and solar projection apparatus available. We had to contend with a broken cloud cover, resulting in short views of the Sun. More bothersome was the continued quiet activity of the Sun, showing only a few small prominences, and no sunspots.  Some of the people, however, did enjoy watching the clouds move in front of the Sun on our solar projection apparatus.

On May 19th, we had the Dob outside Indigo Joe’s in Florence.  Result: another cloudy night.  I should note that at this location, we were literally bathed in high intensity parking lot lights.  Having anticipated this light problem, we had selected the planet Saturn as our only possible target for the evening.  I felt confident that our 10-inch Dob could peer through the light pollution, but there was a definite concern on the ability to aim the scope under the bright lights.  However, our green laser, though barely visible, still allowed us to aim the Dob.  We did have two small breaks in the clouds, both in the area of Saturn.  We observed Saturn from 100-150 power, and the view was quite sharp, although as you well know, the rings were almost edge on.

Dwarf Planets:  Remember when our Sun had nine planets?  As of 2006, we now have only 8 planets; so what happened?  As our technology increased, we began to detect significant objects beyond the planet Pluto.  Everything was fine until Eris was discovered in 2005, and Eris is larger than Pluto, so now we had 10 planets!  However, there was a concern that we would continue to find more objects like Eris, and our planet count would steadily increase.  To prevent this, a new class of solar system objects was proposed, the dwarf planets, and since they definitely wanted to include Eris, and Eris is larger than Pluto, then Pluto had to be demoted to a dwarf planet.  A dwarf planet had to revolve around the Sun and be of sufficient size to coalesce into a sphere, but it could not be a satellite of a planet.  The accepted diameter size range of dwarf planets has not yet been defined. As of today there are five known dwarf planets.  It would appear that the average amateur would have no chance of ever viewing a dwarf planet; but this is not so.  You can view an official dwarf planet this month with a small telescope, or even a pair of binoculars.  The five dwarf planets are: Pluto, Eris, Makemake, Haumea, and Ceres. The first four listed above are much too small and far away for amateur viewing; but Ceres is the largest asteroid in the asteroid belt between Mars and Jupiter, and has a diameter of about 600 miles. 

The asteroid belt, shown below, contains millions of pieces of rocky debris revolving around the Sun between the orbits of Jupiter and Mars.  It was once thought that a planet had formed there, and was then torn apart by the gravitational effects of Jupiter and Mars, or the newly formed planet was destroyed by a massive impact.  The current view is that the material in the asteroid belt could have coalesced into a planet such as the Earth did, but it was unable to do so because of the effect of Jupiter’s gravity.

So this month, let’s try to see the dwarf planet, Ceres.  Below is a Hubble image of the asteroid, now dwarf planet, Ceres.

Below is a depiction of the relative size of Ceres versus the Earth and Moon.

The reason that I chose June 2009 to direct you at Ceres is that in late June it is passing nearby an easy to locate star.  That star is Chort, also called theta Leonis, in the easy to find constellation Leo.  Leo is defined as a backward question mark and a triangle, Chort, is in the triangle; as is shown below.

Note that the circle around Chort in the above and below images is the field of view at 15 power (telescope or binoculars).  The following images show the positions of Ceres on the nights of June 19th, and 20th.  If you live in a dark sky area, first try to locate Ceres with binoculars, if not use a telescope at low power.  Not only is Ceres near a well-known star, but when you look through your binoculars or telescope, it is the brightest star like object that close to Chort.  Once you think you found it, make a simple sketch, and check back in several hours, or the following evening.  If the object has moved, congratulations, you have found the dwarf planet Ceres.

Please note, other asteroids can also be easily seen throughout the year, but only Ceres is an official dwarf planet.

Naked Eye Sights:  Look for the rising of two well-known constellations, Scorpius in the south, and Cygnus in the east.

Binocular Sights (7 to 10 power):  Try for Ceres!  Wander through the region above and to the left of Scorpius, a very rich star field.

Telescope Sights (60-100mm):  Your goal is to locate and track the dwarf planet Ceres.

See you next month!

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