ASTRONOMY CLUB NEWSLETTER

CLUB EVENTS:
Come to our meeting at Explorit Science Center on Saturday April 25, at 7:30 p.m., when we will feature:

A tour of the constellation LEO.

We'll see slides showing how various cultures viewed the star pattern astronomers call Leo. Almost every ancient society along the Mediterranean saw the shape of a lion in the sky. To ancient Greeks, the shape of the lion recalled the great Nemean Lion, which Hercules killed in the first of his legendary "12 labors." The ancient Babylonians also knew it as the Lion ("Aru"), and their symbol for this constellation is similar to our letter A. To the Hebrews, it was the Lion ("Arye") the tribal sign of Judah. To the medieval Christians, it was one of "Daniel's lions from the lions' den."

Because Leo and the sun occupy the same part of the sky in the summer months, the constellation has been identified with the sun's power. This aspect of the hot-blooded and powerful lion eventually found its way onto the Great Seal of England.

The brightest star in Leo is the 20th brightest in the sky. It was named "Regulus" by Copernicus, who, among other accomplishments determined that the sun not the Earth was at the center of the solar system. Regulus means "Little King" and derives from the belief, already thousands of years old in Copernicus's time, that the star was a symbol of heavenly control and authority.

LEO is a grand constellation for observing various types of STARS and several bright galaxies.
STARS: Regulus lies about 72 light years distant, has a diameter approximately 1.6 times that of the sun, is 137 times brighter than our star, and is a double star. Because Regulus lies very near the ecliptic, the path of the Sun through our sky, it is often appears "close" to other solar system objects such as the planets, asteriods and the Moon. The double star Algieba, the "lion's mane" is a good choice for public viewing through a telescope. People see a variety of different colors represented. Most see the stars as orange-yellow. What do you see? The star n Leonis is a distant (1800 light years) supergiant with a diameter 2500 times larger than our sun's and 9500 times brighter. A popular star among variable star observers, R Leonis is a Mira-type variable, a bloated old-age star that usually is barely visible in small telescopes; but around every 310 days it flashes to naked-eye visiblility.

GALAXIES: Within the constellation Leo, a group of four bright galaxies can be found. They are all approximately 29 million light years from Earth. The two brightest, M65 and M66, form a pair that can be glimpsed through binoculars on a very dark night as two wispy objects. A second pair, M95 and M96 lie near Regulus, but are slightly fainter than M65 and M66. Eachof these four galaxies harbor millions of suns.

METEOR SHOWER: During the middle of November the Earth moves through a region in its orbit that contains some remnants of the comet Swift-Tuttle. From our vantage point, it appears that the meteors originate from an area of sky near the "head" of Leo, which rises around midnight at that time of year. The event is called the "Leonid Meteor Shower" The shower this year (1998) may be unusually spectacular, due to the recent return of the comet on its 33 year orbit around the sun.

Our April program continues our series "Where Is That Star?" This series is designed to introduce the novice astronomer to the night sky "one constellation at a time." We have covered Orion, Taurus, and Gemini and now that spring has arrived, we hope a clear night after the meeting will give the club a chance to view them.

REPORT: MARCH ASTRONOMY CLUB MEETING ON GEMINI
Despite overcast skies, 15 intrepid members attended our meeting at Explorit on February 21 to continue our "Where's that Star" series. We saw slides on the are of the sky we know as the constellation Gemini. To Mediterranean cultures, Gemini represented youthful warriors, and protection for seafarers, among other things. The Chinese saw several objects in this constellation, with the "need for water" as their unifying theme. We looked at pictures and maps of the various deep sky objects in Gemini. These included the sextuple-star system we see as the single "star" Castor; we also saw pictures of the eskimo or clown nebula; and M8, a large bright star cluster, near the "foot" of Castor. We also used young volunteer members to create a model of the solar system to show what is meant by the expression: "The Sun is in Gemini."

WHAT'S UP FOR APRIL?

1. Constellations. If you have trouble remembering where the constellations are that we have talked about this year, the Moon will help you this month. On Wednesday, April 1, the Moon will be near the reddish bull's eye, the brightest star in the constellation Taurus, Aldebaran. On the 4th, our natural satellite will be around 10 degrees below Pollux and Castor, the two brightest stars in Gemini. Finally, to prepare you for the subject of our April meeting, the Moon will visit Regulus, the brightest star in Leo, on the Monday, the 6th.
   
2. Planets. Forget looking for the brightest planets in the evening, because Mars, Mercury, Venus, Saturn and Jupiter are either too close to the Sun or are visible only before dawn in the morning hours. So, set your alarm clock for the pre-dawn hour (4:30 to 5:30 a.m.) to the best views of the planets this month. Thursday, April 23rd will show the Moon, below Venus and Jupiter (Venus will be the rightmost of the two planets). Though they seem to our eye to be close to each other, Venus will be 74 million miles away from Earth and Jupiter will be 456 million miles farther than Venus.
3. Meteors. The Lyrid meteor shower will peak in the wee hours of Wednesday, April 22nd. This is a weak shower, with rather faint, slow moving meteors, and the Moon will rise around 3:00 a.m. Good Luck!

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CUBS SCOUT ORION. It was a clear night on the evening of Wednesday, March 4 near Vacaville, when Den 3 of Pack 484 (and several parents) gathered to view the winter constellations, and hear a few stories about the myths of the stars. The importance of Polaris as the "North Star" and how to use the Big Dipper asterism to find Polaris was explained to the young scouts. As is usual in such mixed age gatherings, some of the children possessed more knowledge than some of the parents, and it was an illuminating time for all concerned. And all the more special for the clear sky. If your club or organization is interested in an astronomical presentation, please contact me, Dennis Smith.