Virgo, the Virgin, is a zodiacal constellation that transits the meridian at midnight standard time as spring begins. It lies on the ecliptic between Leo and Libra. Hold your mouse cursor over the image to see constellation figures, boundaries, and star identifications. Virgo is easy to find by using the Big Dipper and the curve of its handle to "arc" to brilliant Arcturus and then continuing the arc and "spiking" to bright Spica, the alpha star in Virgo. Virgo is currently the location of the September equinox. This is the point in the sky where the Sun crosses the celestial equator heading into the southern hemisphere of the sky. This usually occurs around September 22, marking the beginning of fall for the northern hemisphere on Earth, and the start of spring for the southern hemisphere. The equinox is also when the length of the day and night are equal and the Sun rises due east and sets due west. Alpha Virginis is Spica, a magnitude 0.98 spectral-class B blue-giant star that is located 249 light-years away. It is a spectroscopic binary that can't be resolved in a telescope. Gamma Virginis is Porrima, an interesting close double star. It has a combined magnitude of 2.74 with components of almost equal magnitude (3.65 and 3.56) separated by 2 arcseconds in 2013 and located 39 light-years from the Sun. Periastron, when the two stars were closest, occurred in 2005 when the stars were separated by only 0.35 arcseconds. The pair will continue to widen until 2087 when the separation will be 6 arcseconds. SS Virginis (TYC 282-753-1) is a carbon star with a very strong red color. It is a Mira-type variable star whose magnitude changes from 7.4 to 9.5 over a 361-day period. Virgo, lying far from the plane of the Milky Way, does not contain any interesting emission nebulae. It does, however, host the amazing Virgo Galaxy Cluster, which contains an estimated 1,000 to 2,000 galaxies. This cluster is located 54 million light-years away. It can easily be found halfway between Denebola (Beta Leonis) and Vindematrix (Epsilon Virginis). Markarian's Chain is a galaxy group at the heart of the Virgo cluster that contains some of its brightest galaxies. Other interesting deep-sky objects in Virgo include quasar 3C 273 and M104, the Sombrero Galaxy. The Sun is located in the constellation of Virgo from September 16 to October 31. Virgo was cataloged by the Greek astronomer Ptolemy in the second century C.E. (Common Era). It is the second largest of today's 88 modern constellations, covering 1,294 square degrees of sky. North is to the top in the above image.
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