Idaho Skies Transcript for February 15th, 16th, and 17th

RACHEL
Welcome to Idaho Skies for February 15th, 16th, and 17th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
The moon passes a large star cluster this week and many people have never seen it.

PAUL
The cluster is the Beehive star cluster. It has an apparent diameter of ½ of a degree, or as large as the moon. The cluster resides in Cancer the Crab and can be glimpsed without binoculars, if you’re in dark skies. Since the star cluster is reasonably bright, it can be seen in town, but only through your binoculars. 

RACHEL
The Beehive has been known since antiquity. However, its true nature was unknown at the time. Without optical aid, the star cluster only appears as a fuzzy cloud or nebula. Galileo discovered it was actually a collection of stars in 1609. But it took the invention of the telescope for him to make this discovery.

PAUL
On Sunday night, aim your binoculars at the nearly full moon. The moon is skirting the edge of the Beehive, so this is a great opportunity to compare the apparent size of the two. The moon’s light will create enough glare that it will make it difficult to see the faintest of the stars of the cluster. When the moon is not present, you can see around two dozen stars in this cluster.

RACHEL
A star cluster is created from a molecular hydrogen cloud, or a region of gas that’s denser than the gas that normally fills the galaxy.  A shock wave or a passing star can create a slightly denser region in a molecular cloud. That lets gravity overcome gas pressure and shrink the clump of gas even more. And over time, the gas clump breaks up into hundreds or even thousands of tinier clumps that continue to collapse into individual stars.   

PAUL
That’s Idaho Skies for the 15th, 16th, and 17th of February.

RACHEL
Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com.

For Idaho Skies this is Rachel...

PAUL
...and Paul.

RACHEL
Dark skies and bright stars.