Idaho Skies Transcript for April 15th and 16th

PAUL
Welcome to Idaho Skies for April 15th and 16th. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
Ursa Major is located high overhead during April evenings.

RACHEL
The portion of Ursa Major that most people are familiar with is the Big Dipper. The Big Dipper is an asterism, not a constellation. Asterisms are familiar patterns of stars, rather than official astronomical constellations described by the International Astronomical Union. For our curious listeners, there are 88 recognized constellations.

PAUL
The Big Dipper presents something of a vision test. Look for the second star in its handle, or the star at the bend of the handle. Most people with good vision will see that this star is actually two separate stars. Of course, the brighter the background light and the hazier the sky, the more difficult this becomes. You can impress friends and neighbors by telling them that the bright star is named Mizar and the fainter one is named Alcor. 

RACHEL
Humans have known for a long time about Mizar and Alcor. However, in 1650, Italian astronomer Giovanni Riccioli recorded that Mizar itself was a double star. He needed a telescope to magnify Mizar enough to split it into two separate stars. By the way, we celebrate Giovanni’s birthday on Wednesday the 17th.

PAUL
You can replicate Giovani’s observation of Mizar tonight. Just take your binoculars outside and look up. Your binoculars will show a widely spaced Mizar and Alcor. But look carefully and you’ll see that Mizar is two closely spaced stars. Astronomers have discovered that the two stars of Mizar are actually double stars themselves. So Mizar is actually four stars orbiting each other.           

RACHEL
That’s Idaho Skies for the 15th and 16th of April.

PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...

RACHEL
...and Rachel.

PAUL
Dark skies and bright stars.