Skywatch for the week of October 28 , 2019
Tue Oct 29, 2019 ALGOL, THE DEMON STAR/ASTRONOMY CLUB MEET In the northeast sky this evening, in the constellation Perseus the hero, there is a star named Algol. Algol is not particularly bright, but it is quite an unusual star – three stars, actually. The name Algol comes from its Arabic designation as “the demon,” and is also where we get the word, “ghoul.” Algol is a trinary star system, and two of the stars are so aligned with our planet that about every three days, we can observe one star pass directly in front of the other, an eclipsing binary. When that happens, the light from this triple star dims. To the ancients, this was like the winking of a demon’s eye. Algol was thus portrayed as the eye of the snaky-haired gorgon Medusa, whose glance could turn anyone who looked upon her into stone. While you can’t look at a gorgon, you can certainly watch tonight’s meeting of the Treasure Coast Astronomical Society, which will be at 7:30 this evening at Indian River State College’s Science Center in Fort Pierce; come on out and see the stars!
Wed Oct 30, 2019 CROSSING THE ASTEROID BELT Asteroid belts in our solar system range from inside the orbit of Venus all the way out to Neptune; but most of the asteroids can be found between Mars and Jupiter. They are leftover remnants from the solar system’s formation, and have been heavily battered by countless collisions over the years. The gravity field of Jupiter does have a disrupting influence on this part of space, which most likely has kept the asteroids from getting together. It was long feared that the asteroid belt would pose a hazard to spacecraft. But In October of 1972, the unmanned spacecraft Pioneer 10 found itself deep within the belt. When it emerged in February 1973, it demonstrated that navigating the belt was possible. Since then, many more spacecraft have safely made the journey: Pioneer 11; Voyagers 1 and 2; Galileo; Cassini, Juno and New Horizons. There’s a great volume of space between most of the rocks, and the chances of being hit are slim.
Thu Oct 31, 2019 CREATURES OF THE NIGHT If you’re out trick or treating tonight, and the skies are clear, you’ll have a chance to see the new crescent moon nearby the planet Jupiter, over in the southwest after sunset. Besides this pretty sight, there are many constellations suited for Halloween. The three stars in the summer triangle overhead, represent man-eating birds that were chased from the Stymphalian swamps by the hero Hercules. At sunset, the constellations of Scorpius the scorpion - that’s where Jupiter and the moon are - is sinking into the southwest. A scattering of stars in the southeast this evening mark the location of Cetus the Whale – a sea monster in Greek mythology. Perseus the hero, over in the northeast, holds out the snake-haired head of the gorgon Medusa, while Draco the dragon guards the northern skies tonight. And after midnight, Canis Major rises in the southeast. He is associated with the three-headed dog Cerberus who guarded the gates of the Underworld.
Fri Nov 1, 2019 PLACES IN THE SKY - NOVEMBER Can you identify the 15th largest constellation? It is bordered on the north by Scutum the Shield, Aquila the Eagle and Serpens Cauda, the Serpent’s Tail, on the south by Telescopium and the Southern Crown, on the west by Scorpius and Ophiuchus the Serpent Bearer, and on the east by Microscopium and Capricornus the Sea Goat. The center of the galaxy lies in the direction of its western border, and it contains many star clusters and star clouds, such as the Trifid and the Lagoon Nebulae. This constellation has no first magnitude stars, but a handful of 2nd magnitude stars trace out the shape of a teapot. In ancient Greek mythology it represented Chiron, a centaur who taught Hercules and even now, guards the other constellations by keeping Scorpius at bay with his bow and arrow. This evening the moon and the planet Saturn appear above it. Can you name this star figure, the ninth constellation of the zodiac? The answer is Sagittarius the Archer.