August 16 2012 Astronomy Newsletter
Here's the latest article from the Astronomy site at BellaOnline.com.
Henrietta Swan Leavitt
Henrietta Leavitt isn't a well-known name, but a century ago she made one of the most important discoveries of 20th century astronomy. Previously, astronomers could only measure distances up to 100 light years, but her work extended that to 10 million light years.
Once again I have not seen a single Perseid. However I pinned a few to my Pinterest board "Comets". Here is a particularly pretty picture with a view over Denver, Colorado. Thomas O'Brien took it. http://pinterest.com/pin/250090585528399054/ Perseid pictures are on the "Comets" board because meteor showers are caused when Earth's orbit takes us through the debris trail of a comet. The Perseids are bits of comet Swift-Tuttle.
On August 20, 1977 Voyager 2 was launched. It flew past all four of the gas giants and is still the only probe to have studied Uranus and Neptune. Most of what we know about those two planets is thanks to Voyager. Voyager 2 is currently 98.6 AU from Earth in the direction of the constellation Telescopium. Telescopium is a southern hemisphere constellation named by 18th century French astronomer Nicolas Lacaille. Voyager 1 was at 100 AU from Earth on August 17, 2006, but it's now 121.3 AU from us. (The AU, astronomical unit, is equal to the mean Earth-Sun distance.)
*John Flamsteed (1646-1719)
John Flamsteed, the first Astronomer Royal of England, was born on August 19, 1646. His greatest work was his star atlas, the first major one to be produced from telescopic observations. It contained over 3000 stars whose positions he had carefully observed and recorded over four decades. It remained the most authoritative sky atlas for long after his death. In 1798 Caroline Herschel published an index to Flamsteed's catalogue, which made it much easier to use and corrected several hundred errors and omissions in his printed work.
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