Bob Moler's Ephemeris Blog

Tuesday, August 30th.  The sun will rise at 7:02.  It’ll be up for 13 hours and 20 minutes, setting at 8:23.   The moon, 2 days past new, will set at 8:48 this evening.

The Summer Triangle of bright stars is visible overhead and to the south.. Vega is highest, nearly overhead, while Deneb is high in the northeast.  The southernmost star of the Summer Triangle is Altair.  Altair is the closest of the three stars at a distance of 16.8 light years away. One light year is nearly 6 trillion miles. Altair is 10 times the brightness of the sun. If seen at Altair’s distance, the sun would only be as bright as one of the two stars that flank it. What is rather different about Altair is it’s rapid rotation. While its almost twice the sun’s diameter, it rotates once in only 6 ½ to 10 hours, and would show a decidedly squashed appearance if seen close up. Our sun’s a slow poke, taking nearly a month to rotate just once.

* Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.