Monday, July 30, 2012

Venus near Orion "club-top" stars

Event Date: August 7th
Time: 5:04(.37) AM


Brief

   Orion's club--held in his right hand--has two stars marking the top of it: Chi1 and Chi2 Orionis.  Yesterday, Venus passed close to Chi1, about 0.7º apart from it.  Today is a little interesting: although not passing as close to Chi1 as yesterday, it is exactly the same separation from both Chi stars at the time above, at 1º 15' 14".  The first image shows a zoom-out with Orion's stick-figure included.
Using that, try viewing Orion a little earlier with a darker sky, and see if Venus' placement helps you find these stars with the eye alone.  Venus, unlabeled yet bright enough, is seen between the star labels.




Detailed

 If you look at them through a wide-field telescope or powerful binoculars, you can probably notice this.  Looking with the eye alone at this time is much more challenging: the sky is already getting brighter and the stars are 4th magnitude, with Chi1 slightly brighter.  It can also be difficult to see the star for two other reasons: there is a 71% waning gibbous Moon high in the sky, still washing it out somewhat, while this section of Orion's constellation is where the Milky Way passes through.  Although this arm, the Orion Arm, isn't as dense and thick-looking as the center where we see Sagittarius' Teapot somewhat dimly, it is still enough stars far in the "background" to make the Chi stars a bit more challenging to see.
   This second image is a 5º zoom-in, showing waxing-crescent Venus with the two stars.  This is a powerful binocular view, although a low f-ratio telescope can provide a large enough field of about 3º, to fit all three as well.

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

No comments:

Post a Comment