Casper Planetarium

Virgo Offers a Different Sort of Observing Experience
06.10.2013

Story Image

Virgo Offers a Different Sort of Observing Experience
by Rod Kennedy

June 2013 may seem rather anti-climatic after the triple conjunction of Mercury, Venus and Jupiter in May. However, while Jupiter is lost in the glare of the sun, Mercury and Venus will continue to be visible, as well as Saturn. In fact, Saturn is in great position to be observed during the short nights of June. The constellation Virgo the Maiden is also a great place to hunt for deep sky objects. So dust off that telescope, head for an observing sight away from city lights and get ready to observe!

Saturn is easy to find in the constellation Virgo. The easiest way to find Saturn is to first look north and find the Big Dipper. Follow the curve of the handle (the Arc) to a bright orange star almost at the zenith. This star is Arcturus, the brightest star in Boötes the Herdsman. Keep going toward the South until you find a bright bluish star. This is Spica, the brightest star in Virgo. To the East of Spica is an equally bright object that appears yellow or butter colored. This is Saturn. While Saturn is beautiful to the unaided eye, it is best appreciated through a telescope. Even a small, low power, eyepiece shows the stunning rings.

Once you’ve tired of observing Saturn, turn the telescope toward the few double stars in Virgo. The best is Gamma Virginis or Porrima. The two components of Porrima are almost identical in their spectral type and brightness. The orbit of the companion star is such that at its closest approach the pair is almost inseparable in small telescopes. The last close approach occurred in 2007. Porrima is the star to the west and slightly above Spica.

Another interesting star in Virgo is Epsilon Virginis or Vinemaitrix. This star’s name means “The Grape Gatherer” because it rises with the sun about the time when grapes are harvested for making wine. This star is a type G star like our sun at a distance of about 102 light years away.

Perhaps the most striking feature of the constellation Virgo is the Virgo Galaxy Cluster. The Virgo Cluster is spread across space from Virgo to Denebola in Leo the Lion. This region of the sky contains literally thousands of galaxies, of which a hundred or so are visible to a good 6inch diameter telescope. None of the galaxies of the Virgo Cluster will appear large or bright in the average back-yard telescope. Most look like faint, fuzzy oval blobs. The striking thing about the Virgo Cluster is that every one of these “blobs” is a cosmic city containing millions or billions of stars. The best way to observe the galaxies of the Virgo Cluster is with a 6 inch or larger diameter telescope under clear, dark, moonless skies. Letting your eyes get completely dark adapted is essential and low power, wide field eyepieces are best to find individual galaxies. Some of the best examples of Virgo Cluster galaxies are: M84 and M86. These two galaxies lie less than a quarter of a degree from each other and should be easily visible in the same field of view under low power.

Unlike most constellations that contain a wide variety of double stars, star clusters, and nebulae, the constellation Virgo the Maiden is relatively empty of such deep sky objects. But what Virgo lacks in interesting “nearby” objects it makes up for in a wide field of thousands of galaxies. Each of these galaxies is a stellar city like our own Milky Way, crammed full of stars and possibly even planets. Do any of those stars have planets with intelligent life? We may never now. But observing the Virgo Galaxy Cluster on a clear dark night certainly allows our minds to wander to the extraordinary possibility that we are not alone in the Universe.