STAR GAZER
THE INTERNATIONAL EDITION
Lorain County JVS NASA CORE / 15181 Route 58 South / 440/775-1400 / FAX 440/775-1460 / nasaco@leeca.org / http://core.nasa.gov
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Horkheimer: Greetings, greetings fellow star gazers.
It's that time of year again when the night skies almost shout,
"spring is here" because Leo the Lion is chasing Orion
and replacing him as the major constellation for early evening
viewers. Let me show you.
Now most of you know that Orion the Hunter is winter's most famous star pattern. Indeed if you go outside in early evening in December Orion is climbing up the eastern skies as a celestial announcement of the imminent arrival of winter. And in January and February when winter is coldest Orion reaches his highest point in the heavens in early evening almost bragging that he is master of the season. But then things begin to change because all through March Orion slowly relinquishes his high flying position in early evening and by the beginning of April is tipped over on his side in the southwest, almost hanging on to the sky for dear life. And it is this position of Orion in the southwest heavens in early evening that always tells us that winter is coming to an end.
And although I am always sad to see Orion's bright stars go, nevertheless a much bigger although less bright constellation takes his place almost overhead in early evening, Leo the Lion, roaring that he is master now and that he and he alone will dominate spring's skies. In fact if you go out any night in late March or April in early evening you will see leo casually reclining almost overhead just as the ancient Egyptians depicted him in a regal sphinx-like position, very self assured that winter and Orion will soon be history. His head and forequarters are indicated by a backward question mark with the bright blue-white star Regulus marking his heart. His rear is marked by a triangle of stars and it is here that we find Leo's second brightest star Denebola.
Now in ancient times lions were often associated with royalty. In fact Leo's brightest star Regulus means "the little king". But little it is not. Some latest measurements indicate that it is more than four and a half times the diameter of our almost one million mile wide Sun. But because it is a much hotter star it is 140 times brighter! And because it is a whopping 80 light years away, when we look at Regulus this spring we see the light that left it 80 years ago. And although Denebola is twice as close, only 40 light years away, and half as big as Regulus, it is much cooler than Regulus, only 14 times brighter than our sun, which is why it appears dimmer than Regulus. Even so if we moved either Denebola or Regulus as close to Earth as our Sun is we'd all be crispy critters.
So welcome in springtime the cosmic way. Simply go outside in early evening any night in late march and April, look toward the southwest and you'll see Orion on his way out and then look almost overhead and you'll see Leo the Lion, the king of spring. Keep looking up!
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Horkheimer: You can tell that spring is here because Leo the Lion is chasing Orion. In early evening look southwest and you'll see winter's superstar Orion the Hunter getting ready to exit and making way for Leo the king of spring. Reclining like a giant cosmic sphinx, almost overhead, Leo's two brightest stars put our Sun to shame. His heart star Regulus is 4 and 1/2 times bigger and 140 times brighter, whereas Leo's tail star Denebola is twice as big as our Sun and 14 times brighter. So if we moved Denebola or Regulus to where our Sun is we'd all be crispy critters. Say farewell to Orion and hello to the lion. Keep looking up!
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* This week's Sky At A Glance and
Planet Roundup from Sky & Telescope.Starry Night Deluxe was used to produce this episode
of Star Gazer
![[SmilinJack]](jack1sm.jpg)
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