Greetings, stargazers.
Thanks for reading my first Thursday column. Although the nights are very short as we approach the summer solstice, there still are lots of things to see after it gets dark.
Last month, I talked about the constellation Virgo and mentioned the numerous galaxies within its borders. Most of those galaxies are part of the Virgo cluster. The Virgo cluster subtends over 5 degrees in the night sky, or more than 10 times the diameter of the moon. It contains over 1,300 member galaxies, many of which are visible through a small telescope.
Many of the brighter galaxies in the Virgo cluster were discovered in the late 1700s and are included in Charles Messier’s list of fuzzy things that weren’t comets. It now is taken for granted that galaxies contain billions of individual stars, but it wasn’t until the early 20th century that this was recognized. And it wasn’t until the late 20th century that it became possible to map the locations of galaxies with enough detail to get any large-scale structure of the universe.
Just as stars often are found in clusters, so are galaxies. Our local cluster of galaxies includes the Milky Way, the Andromeda Galaxy (M31), the Triangulum Galaxy (M33) and numerous smaller elliptical and irregular galaxies. The Local cluster and the Virgo cluster are just two of many clusters that form the Laniakea Supercluster of galaxies that contains about 100,000 galaxies.
As an example of how our understanding of the structure of the universe still is evolving, the Laniakea Supercluster was defined only in September of last year. This Hawaiian name literally translates as immeasurable heaven. Since this is where we all live, it might be useful to remember this part of our address in the universe.
This month:
‰ Venus and Jupiter are the two brightest things in the sky besides the sun and the moon. They both are in the western sky right after sunset and in the next couple of weeks will be getting even closer to each other.
‰ On June 20, both the crescent moon and Venus will be about 5 degrees away from Jupiter in the sky. You should be able to cover them all – almost – with a fist held at arms length.
‰ The more spectacular, however, might be June 30, when Venus and Jupiter are within a half degree of each other.
‰ In late June, the planet Mercury briefly will be a morning star. You can find it near the star Aldebaran in the constellation Taurus. Its greatest distance from the sun will occur June 24.
There are several upcoming star parties, and I hope you try to attend at least one. Join the Four Corners Stargazers (a Google group) to get more up-to-the-day event information. Many thanks go to local stargazer John Buting for coordinating the observing programs at many of these summer events.
Chimney Rock has plans for a telescope viewing after its evening archaeo-astronomy talks Friday, and Durango Nature Studies will host a stargazing program Wednesday. There are small fees for both events.
Because I am writing this column ahead of time, and the weather always can be tricky to predict, be sure to check for details before you go.
hakes_c@fortlewis.edu. Charles Hakes is an assistant professor in the physics and engineering department at Fort Lewis College and is director of the Fort Lewis Observatory.
Useful links
Laniakea Supercluster: http://en.wikipedia.org/wiki/Laniakea_Supercluster
Astronomy picture of the day: http://apod.nasa.gov/apod/
An Astronomer’s forecast for Durango: www.cleardarksky.com/c/DrngoCOkey.html?1
Old Fort Lewis Observatory: www.fortlewis.edu/observatory
Four Corners Stargazers: http://groups.google.com/group/Four-Corners-Stargazers
