Wednesday, May 29, 2013

Virgo






























Right now is an outstanding time of year to view the constellation Virgo the Virgin, high in the southern sky (for northern-hemisphere viewers) right around 10 pm.  And, as the moon is not rising until after midnight right now, the hours after sunset and before midnight provide a wonderful opportunity to gaze at the breathtaking array of stars along the ecliptic path.

Due to the turning of our earth on its axis, all stars appear to make an arcing path from the eastern horizon to the western horizon, reaching their highest point in between as they pass through (or transit) the "local meridian" -- that meridian of the celestial globe that runs through the celestial north pole and continues to the "due south" point on the southern horizon to the celestial south pole (which is out of sight below the horizon for many northern hemisphere viewers).  The crossing of this line marks the highest point of the sky for any star in its circular path, and is known as the star's "transit." 

Currently, the brightest star of Virgo -- the star Spica -- is transiting or reaching the highest point on its arc at about 10pm (and a few minutes earlier each night). 

One of the easiest ways to find Spica is to look for the small, bright, distinctive constellation of Corvus the Crow, who is always perched near Virgo, staring intently at the jewel of Spica.  In the diagram above, you can easily make out Corvus below Virgo.  

In the diagram above, I have added some lines to the outline of Virgo in order to correspond to the system of H.A. Rey, which I believe is much more user-friendly than any other constellation-outlining system I've ever seen (and which is the one I've used from the time I was a child, and which is described in the first two books discussed in this previous post, the top one for young children and the second one for older children and adults).

The planet Saturn is still passing through the constellation Virgo, just as he was two years ago when discussed in this post from 2011.   Then, Saturn was close to Porrima (the star marked by a green arrow in that previous post), but is now east of Spica, below the star that is connected to Spica (which is marked by a red arrow) by a line going straight to the left from Spica in the diagram in that previous post.  That previous post diagram is included below for ease of reference.

Saturn should be very bright and fairly golden in color.  You will have no trouble finding it, once you have followed Corvus to Spica.  Take some time to trace out the entire outline of Virgo, which is easy to do right now (but which is not always so easy).  It is a large and incredibly important constellation.  Further wast from Virgo, you should also have no problem spotting the majestic constellation of Leo the Lion.  If you haven't already done so, you might want to check out this previous post on some of the fascinating connections of these two constellations.

Further east from Virgo, you will also have no trouble finding the sinuous shape of Scorpio rising up from the horizon.

This is truly an excellent time to enjoy the dazzling panoply of the heavens.  I hope you can do so if at all possible.