Mon Dec 11, 2023 SUMMER TRIANGLE IN WINTER/THE NORTHERN CROSS
The Summer Triangle has three bright stars: Vega, Altair, and Deneb. Vega is in the constellation Lyra the Harp; Altair is in Aquila the Eagle; and Deneb is in Cygnus the Swan. It’s hard to recognize most constellation figures, so we come up with easier shapes to find. In the constellation of Cygnus the Swan, there is a simpler pattern called the Northern Cross. The tail of Cygnus, the star Deneb, marks the top of the cross; while the bird’s beak, the star Albirio, is at the foot of the cross; and the wings of Cygnus form the crosspiece. In the summer and the early fall, Cygnus is overhead. But now as winter approaches the swan has moved toward the horizon, and the Northern Cross now stands upright in the west after sunset.
Tue Dec 12, 2023 ORION’S RETURN
The ancient constellation Orion the Hunter has returned to our evening skies. He rises out of the east around 8 o’clock tonight. In Robert Frost's "The Star Splitter," the poet begins by saying, "You know Orion always comes up sideways. Throwing a leg up over our fence of mountains, And rising on his hands, he looks in on me Busy outdoors by lantern-light." Orion does come up sideways, first his left shoulder, the star Bellatrix, and the hunter's knee, the star Rigel; then three bright stars in a row which form his belt, followed by Betelgeuse in Orion's right shoulder, and finally his right leg, the star Saiph. When I was young, I saw Orion, looking just as he does now, as did my grandparents, and their grandparents, and so on back for thousands of years.
Wed Dec 13, 2023 GEMINIDS
The Geminid Meteor Shower is here. This display of shooting stars comes from the direction of the constellation Gemini, hence the name “Geminids.” The Geminids are a fairly reliable shower, and under clear, dark skies, should generate a few dozen meteors each hour, some of them bright fireballs. The shower reaches peak activity tonight, with lesser numbers of meteors through December 17. Best views should be in the late evening until dawn. Face east and look upward toward the zenith for best results. Get away from bright streetlights that can spoil your view. Make sure you have permission to be at whatever location you choose, dress warmly and protect yourself from mosquitoes.
Thu Dec 14, 2023 TYCHO BRAHE
Tycho Brahe, born on December 14th, 1546, was a Danish nobleman who had an artificial nose made of brass – he’d lost his original nose in a fencing duel over an argument with another scholar about a math problem. (Actually, this happens a lot. Not the duel, the arguing.) But it turns out he was a great astronomer. Tycho proved by its parallax that a comet was far beyond the moon; it used to be thought that comets were simply gases in the atmosphere. From Tycho’s island observatory, and before telescopes were invented, he made incredibly accurate measurements of star and planet positions. It was this data that made it possible for his colleague Johannes Kepler to figure out that the shapes of the orbits of planets about the sun are not round, but elliptical.
Fri Dec 15, 2023 NAME THAT CONSTELLATION – DECEMBER
Can you identify the 40th largest constellation? It is bordered on the north by Aquarius and Aquila; on the south by Microscopium and the Southern Fish, on the west by Sagittarius; and on the east by Aquarius again. This constellation lacks brilliant stars, but a scattering of 2nd magnitude stars trace out a wedge shape. In myth it represents the god Pan, who taught people how to play the flute, and the conch, a favorite of Floridians. When a dragon attacked Pan, he grew a fish’s tail, jumped into a river and swam away. Tonight the moon and the planet Saturn appear on either side of this constellation. Can you name this star figure, the tenth constellation of the zodiac? The answer is Capricornus, the Sea Goat, visible in the southwest after sunset.
