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If you have trouble viewing this newsletter, click here. Welcome again to our monthly newsletter with features on exciting celestial events, product reviews, tips & tricks, and a monthly sky calendar. We hope you enjoy it!
There's a misconception that in order to do real science and make astronomical discoveries, you have to be a professional astronomer. With modern telescopes and cameras, not to mention the internet, this is no longer true (if it ever was true). How can you, the amateur astronomer, get your fingers into the vast, empty, cold pie of astronomical research? Read on! Comets Comets are perhaps the most well-known amateur discoveries, because the International Astronomical Union officially names comets after their discoverers. What stargazer doesn't dream of that kind of glory? While the first named comet was named for Sir Edmund Halley, the man who calculated its orbit and predicted its return, modern astronomers simply have to find a comet and confirm that nobody knew about it already in order to get their name on it. The most successful comet-hunters are the ones who use photography in their searches. Carolyn Shoemaker has her name on more comets than does any other person, due to her participation in comet-hunting teams that use this method. Visual comet-hunters are dedicated folks who know the sky very well and spend hours peering through telescopes and binoculars, to find faint fuzzy objects where there aren't supposed to be any. Those of you who were looking skywards in the late 1990s will remember the spectacular naked-eye comets Hyakutake and Hale-Bopp; Alan Hale, Tom Bopp, and the late Yuji Hyakutake all made their discoveries at the eyepiece.
Comet Hale-Bopp as seen over Croatia in March of 1997. (Philipp Salzgeber) The age of amateur telescopic discovery may be winding down, as photographic and robotic surveys are much more efficient at finding faint comets long before they come within range of your average backyard scope. Still, visual comet-hunters are out there catching the few that fall through the cracks; as recently as March of this year a new comet was picked up by prolific visual observer Don Machholz. To read the rest of this article, click here.
What, you may ask, is a “dwarf planet”? Basically it is a solar system object which is too small to qualify as a planet. Interestingly enough, both Ceres and Pluto were, at the time of their discovery, considered to be planets. When Giuseppe Piazzi discovered Ceres on the first night of the 19th century, he thought he had discovered a new planet circling in an orbit between those of Mars and Jupiter. Later Ceres was demoted to become the largest of the asteroids, but in 2006 was elevated to the status of a dwarf planet. Ceres is named for the Roman goddess of plants, the same source from which our word “cereal” comes. It is a small world, just 940 kilometers in diameter. Similarly, when Clyde Tombaugh discovered Pluto in 1930, he thought it was a new planet in an orbit beyond that of Neptune. However, its small size and peculiar orbit led astronomers to doubt its status and in 2006 Pluto too was reclassified as a dwarf planet. Pluto was named by an 11-year-old English girl, Venetia Burney, after the Roman god of the Underworld. It is a little more than twice the size of Ceres, 2300 kilometers in diameter, slightly smaller than Eris, the largest dwarf planet. All of these dwarves are tiny compared to our Moon, 3500 kilometers in diameter. Both these small objects are well placed for observation this month, with a bit of help from Starry Night.
To read the rest of this article, click here.
In its yearly path around the ecliptic, the Sun reaches its maximum northern declination on June 21, 2010 at 11:28 UT. Astronomically, this point is known as the solstice. New Yorkers also know it as the moment summer begins -- the summer solstice. Here the Sun reaches its maximum altitude, almost 73 degrees. Meanwhile, in Miami, 14 degrees further south, the Sun reaches an altitude of 87 degrees. This is only 3 degrees from the zenith or overhead point. So it stands to reason that 3 degrees south of Miami, the Sun should be a the zenith. The Sun, June 21, 2010, local noon
What if we went further south? For each degree we travel south, the Sun gains a degree in altitude. Thus at the equator (0 deg N) the Sun will have an altitude of 113 degrees. But wait a minute! The maximum altitude possible is 90 degrees. What happens now? Let’s check it out. To read the rest of this article, click here.
Summer Constellations The Summer Triangle dominates the summer sky. It crosses the hazy band of the Milky Way, which is split into two near the star Deneb by a large dust cloud called the Cygnus Rift. The points of the triangle are three of the brightest stars in the summer sky, each the brightest star in its own constellation. The brightest is Vega, in Lyra; second is Altair, in Aquila; and third is Deneb, in Cygnus. Even city-dwellers with glowing, light-polluted skies can find the Summer Triangle. Using the Big Dipper as the guide to the other stars and constellations, imagine a line extending 75 degrees of sky from the two bowl stars closest to the handle, to a point in the middle of the Summer Triangle. Stretch out your arm out at full length and measure about three spread hands from little finger to thumb. Each hand covers about 25 degrees of sky. Pedro Braganca
Don't let the scale of the diagram above fool you: representing the goddess of justice, Virgo is the second largest constellation in the sky. Spica, a first magnitude blue-white star, is easy to spot, shining as it does in a fairly dark part of the sky. M49 and M60 are elliptical galaxies. Being one of the brightest ellipticals, M49 was the first member of the Virgo-Supercluster to be discovered by Charles Messier. M60 is some 60,000,000 light years distant and is as luminous as 60 billion copies of our sun. Most of the galaxies in Virgo are part of the Virgo-Supercluster. Not so M104. At about 50,000,000 light years, this galaxy's dark dust lane and close to edge-on angle (just 6°) makes it look a little like a sombrero. M61 is a lovely face-on spiral galaxy while NGC 5746 is an edge-on spiral galaxy that's best observed in small scopes. Finally, Porrima is a fine double-star worthy of a peek. Sean O'Dwyer
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JUN 2010
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