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07/04/11 – Ephemeris – Red, white and blue stars
Independence Day, Monday, July 4th. Today the sun will be up for 15 hours and 27 minutes, setting at 9:30. The moon, 3 days past new, will set at 11:22 this evening. Tomorrow the sun will rise at 6:03.
Today’s Independence Day so let’s look for some red, white, and blue stars. Red is easy, the red star Antares is seen in the south at 11 p.m. White is easy too, the official white calibration star Vega high in the east at 11 p.m. The blue star is really blue-white. The brightest of these out at 11 p.m. is Spica, low in the southwest. The color is best seen in binoculars. Star colors are quite subtle, and are an indicator of the temperature of their outer gaseous layers. The temperature of a stars outer layers, in order of their increasing temperatures, red, white and blue, is not related to the temperature in their cores. Of these three the coolest on the outside, Antares is really the hottest inside, using helium as fuel.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
07//01/11 – Ephemeris – Meteorite program at the GTAS
Friday, July 1st. Today the sun will be up for 15 hours and 30 minutes, setting at 9:31. The moon is new today, and won’t be visible. | Tomorrow the sun will rise at 6:01.
Those fascinating bits of rock and metal that fall from the sky, called meteorites will be the subject tonight as the Grand Traverse Astronomical Society holds its monthly meeting at Northwestern Michigan College’s Rogers Observatory starting at 8 p.m. Society member Joe Brooks has a collection of these celestial visitors, and has visited area schools with his collection. Meteorites, for the most part, come from the asteroid belt, bits of a planet that was destroyed or never quite formed due to Jupiter’s disruptive gravitational influence. He has one that may be part of the asteroid Vesta that the Dawn Spacecraft is visiting this month. The observatory is located south of Traverse City, on Birmley Road between Keystone and Garfield roads.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Bob Moler's Ephemeris Blog 