by Juan Ivaldi, volunteer amateur astronomer at the NPFO

 

The Earth hurls through space at a remarkable average speed of 67,000 miles per hour as it makes its annual journey around the Sun.  Each year the Earth reaches a special point in that amazing journey called the autumnal equinox.  The 2008 autumnal equinox occurs on September 22nd and marks the beginning of fall for the Northern Hemisphere.  Near the time of autumnal equinox, the length of the day from sunrise to sunset is very close to 12 hours in duration and the length of the day decreases at its fastest rate of the whole year.  This is often when observers remark at how much earlier the Sun seems to be setting.  For astronomers, it is time to enjoy the wonders of the fall night skies! 

 

During the fall, the Milky way stretches overhead after nightfall.  On clear, moonless nights it is easily seen from the New Pond Farm Observatory.  Observers can also look for the prominent constellations of fall: Andromeda, Perseus, Cassiopeia, and Pegasus.  The first three constellations are connected in Greek mythology and it is therefore fitting that they are close to each other in the sky.  

 

The constellation Andromeda is home to the Andromeda galaxy which is the closest spiral galaxy neighbor to our own Milky Way and is visible to the unaided eye during excellent seeing conditions.  Perseus sports the famous variable star named Algol.  Algol is an eclipsing binary.  This means that a smaller companion star orbits the main star and periodically blocks a portion of the main star’s light.  Every 2.9 days like clockwork, Algol dims in apparent brightness owing to these regular eclipses.   From Perseus on the way to Cassiopeia lies the beautiful and large Double Cluster.  This is a gorgeous sight in binoculars and telescopes: two open clusters in close proximity containing many bright stars.  Fall is a great time for globular clusters in general as many of them are peppered along the arms of the Milky Way overhead.  Finally, Pegasus, the magnificent flying horse frames the fall sky with its giant rectangular shape almost directly overhead in the evening hours well past nightfall.  

 

These wonders and many others can be observed at the monthly public programs held at the New Pond Farm Observatory.  Observing programs are announced in the Redding Pilot and via email to members requesting to be on the astronomy distribution list.  Please call the farm with your information if you wish to have your email address added to the list.  The team of volunteer astronomers looks forward to sharing the dark Redding skies with you!