Tonight is Sep 02, 2010
Courtesy U.S. Naval Observatory
At early evening, look up high for the brilliant star Capella, the brightest in the constellation Auriga the Charioteer. Close to Capella is a prominent triangle of starlets called The Kids. Lighting up the apex of this triangle is the star Epsilon Aurigae (Almaaz), one of the most mysterious stars in all the heavens.
Although Capella looks much brighter than Epsilon, that’s because Capella is so much closer. Capella resides about 42 light-years away, whereas Epsilon is probably over 2,000 light-years distant. If this supergiant star were as close as Capella, it’d outshine Capella by some 150 times.
In cycles of 27 years, the light from Epsilon Aurigae dims for a period of two years. The star’s last dimming happened in 1982-1984. Epsilon was predicted to dim again, starting in August 2009 and to be totally eclipsed by December 21, 2009. Epsilon is an eclipsing binary star, whereby some “dark” star routinely eclipses the brighter star.
The dark body in this binary system might be a star that’s surrounded by a large disk of dust. But nobody knows for sure. No doubt, astronomers will be studying Epsilon Aurigae during its 2009-2011 dimming, to see if they can unlock the secret of this mystery star.
Tonight for binoculars:
Asteroid Vesta still lodges close to Leo’s star Algieba (Gamma Leonis). For a sky chart and more information, go back to our February 17 show: Asteroid Vesta at apposition in Leo the Lion.
What is tonights moon? Also, what was the moon on the 13th, 14th? thaks for your help!!
Lisa,
Between new moon and first quarter moon, the moon is a waxing crescent. New Moon falls on February 13, 2010 (by U.S. clocks) and the first quarter moon falls on February 21, 2010 (by U.S. clocks).
Bruce
Last night-2/17/2010 at about 7:00 CST I saw Mars and two other very visible planets/stars in a line South of Mars and east of Orions Belt.
Can someone tell me what are these other two planets/stars?
Nancy,
I’m sure you were looking at these two stars: Sirius and Procyon. Sirius is the brightest star in the nighttime sky, and you can find it by drawing a line downward through Orion’s Belt. Throughout February and March 2010, you can locate Procyon in between Sirius and Mars.
Bruce
Bruce,
Thank you. I really thought they might be Venus and Jupiter. Oh well
what do I know…
Nancy,
You kmow Orion’s Belt! Once you know that, you can find your way through the starry heavens. Venus and Jupiter are hard to see right now, because they’re in the glare of the sun. Starting in late March or April, Venus will appear in the western sky after sunset and Jupiter will appear in the east shortly before sunrise.
Bruce
Last night I saw a bright star/planet almost overhead (in Seattle) about 10pm. Is it Aldeberon(sp?) or Mars?
Dave.
Yes, it was Mars. Draw a line upwards through Orion’s Belt to locate Aldebaran.
Bruce
What, if anything, can be seen of epsilon-auriga during its dimming?
j.t. lipps,
Epsilon Aurigae can be seen fairly easily with the unaided eye on a dark, moonless night – even during its period of dimming. Look for the bright yellow star Capella first, then for nearby Epsilon. But not much else can be seen – at least through amateur telescopes. Hopefully, this time around, high-powered telescopes will be able to unlock some of the secrets of this mysterious star!
Bruce