WPBT2's Star Gazers

Episode #13-09 "Three Stars with Really Nifty Names and Comet Alert!"
Air Dates March 4, 2013 - March 10, 2013

DEAN: Hey there Star Gazers. I'm Dean Regas, astronomer for the Cincinnati Observatory.

JAMES: And I'm James Albury director of the Kika Silva Pla Planetarium in Gainesville Florida

MARLENE: And I'm Marlene Hidalgo, science teacher from Miami-Dade County Florida.

JAMES: Every march we like to tell you about three of our favorite stars because they're so easy to find in evening skies. Let's show you.


DEAN: O.K., we've got our skies set up for any night this month in early evening. Face south and look carefully for three stars that appear to be equally spaced and lined up in a row. They're easy to find because they're the only three such equally spaced stars visible to the naked eye.

JAMES: Now for thousands of years in many cultures these three stars have been seen either as the waist or belt of a great sky giant, usually male but sometimes, female. Two bright stars above these three mark the giant's shoulders and the two bright stars below mark the giant's knees. And although this cosmic giant has been called many names throughout history, the name we use today is "Orion" who was a giant warrior hunter in ancient Greek and Roman mythology.

MARLENE: His three belt stars fascinate me for two reasons: one, because they are the only equally spaced stars you can see with the naked eye and two, for some reason I just love the sound of their names. Alnitak,
Alnilam and Mintaka.

DEAN: Now according to some sources the name Alnilam comes from the Arabic and means "string of pearls" which can also refer to all three stars. Alnitak means "girdle" and Mintaka means "belt". But no matter what they mean I just love to pronounce their names: Alnitak, Alnilam, Mintaka. They sound so poetic don't they?

JAMES: The 19th century poet Alfred lord Tennyson wrote, "Those three stars of the airy giant's zone that glitter burnished by the frosty dark." But in addition to their poetic beauty, their science is equally wonderful and compared to our sun, they'll take your breath away.


MARLENE: While our sun is almost a million miles in diameter, Mintaka is 24 times as wide. And Alnitak is a bit larger, 25 times as wide as our sun. While sandwiched between them, Alnilam blows both of them away at a whopping 44 times the width of our own sun. Wow!

DEAN: But if that's not enough to impress you then think about how far away these three are. We measure distance to the stars in terms of the speed of light. Because the stars are so far away the term miles is almost useless. Light travels 186,000 miles per second. So we say that our sun is 8 1/3 light minutes away because it takes 8 1/3 minutes for light to reach us from our sun. So we actually see our sun as it existed 8 1/3 minutes ago.

JAMES: The belt stars of Orion however are much farther away. Alnitak is 826 light years away, Mintaka 919 and Alnilam 1359 light years away, which means that it takes about 1000 years for their light to reach us. So when we look at Alnitak, Alnilam and Mintaka we are seeing them not as they exist now but as they existed 1000 years ago!


JAMES: But now for something which is happening right now. This Sunday, March 10th, the comet Panstarrs c/2011 l4 is going to come closest to the sun in its orbit. And for the next few days afterwards it may put on a spectacular show in the western sky after sunset.

MARLENE: Here is what the comet is expected to do. March 8th, 9th, 10th, 11th, and 12th here comes a skinny crescent moon into the picture. The next night, the 13th, the moon is 13 degrees higher and may appear to be in the tail of the comet, but really the moon is much closer to us. Then here it is the 14th, 15th and so on.

DEAN: We feel very confident that this is where the comet is going to be in the sky on these nights but exactly how bright it will be is still up in the air. We really can't tell what will happen with this comet, check with our website -- stargazersonline.org for the latest info.

JAMES:  If Panstarrs puts on a grand show remember you heard about it here. But if it doesn't, you still have Alnitak, Alnilam and Mintaka, three more good reasons to

THREE:  Keep looking up!


Episode #13-09 "Three Stars with Really Nifty Names and Comet Alert!"
Air Dates March 4, 2013 - March 10, 2013

MARLENE: We'd like to show you how to find three of our favorite stars every March in early evening.


DEAN: Face south and you'll see three equally spaced stars. They mark the belt of Orion. And I just love the sound of their names; Alnitak, Alnilam, Mintaka.

MARLENE:  All three make our sun look puny by comparison. Even the smallest, Mintaka, is 24 times the diameter of our own million mile wide sun; Alnitak is 25 times as wide and Alnilam 44 times as wide. And we see them not as they exist now but as they existed 1000 years ago.


DEAN: But for something happening sooner than 1000 years look west after sunset next week and there may be a bright comet called Panstarrs visible above the setting sun. Here's what we hope to see on March 10th, 11th, 12th and 13th.

MARLENE: Check with our website stargazersonline.org for the latest info.

BOTH: Keep looking up!


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