Skywatch for the week of April 29, 2019
Tue Apr 30, 2019 ASTRONOMY CLUB MEETING/SHAPLEY-CURTIS DEBATE On April 26, 1920, a debate took place concerning our Milky Way. Some astronomers thought we were at the center of our galaxy, for when you looked along the milky band of stars that defines the galactic disc, you saw roughly the same number of stars throughout. Other astronomers pointed to a concentration of star clusters in the direction of the constellation Sagittarius, and suggested that that was where the galaxy’s center lay. Spiral nebulas were also considered, and while some thought they were simply forming solar systems inside the Milky Way, others said they were actually other galaxies far beyond ours. Now tonight there will be another meeting of astronomers – amateur astronomers, that is. The Treasure Coast Astronomical Society will hold its monthly meeting at 7:30 pm in the Science Center’s big auditorium on the Fort Pierce campus of Indian River State College. This meeting is open to the public.
Wed May 1, 2019 SPRING CROSS QUARTER DAY, VIRGO AS SKY MARKER Divide the year up into four parts or quarters. Each quarter is marked by the beginning of a new season. The quarter days of Summer and Winter are known as solstices, when the noontime sun reaches its highest or lowest altitude in the sky; while during the equinoxes of Spring and Autumn, nights and days are of fairly equal length. Now divide those seasons in half and you get cross-quarter days, the midpoints of each season. May 1st marks the cross-quarter day for Spring, called Beltane in the old Celtic calendar. In traditional maypole dances, everyone moved clockwise around the maypole, mimicking the sun’s motion across the sky through the day. At the beginning of spring, the stars of the constellation Virgo, the springtime maiden, appeared in the east after sunset. Now Virgo is well up in the southeastern sky, and at summer’s beginning it will be high in the south. But as autumn approaches, Virgo will sink into the west, and we’ll lose sight of it as we move toward winter
Thu May 2, 2019 EXPLORING STARS AND PLANETS I’m offering a class on the Universe that starts next week; unlike most of the classes I teach, this one only meets once a week for just six weeks, and in it I cover some of the basics in astronomy, such as star and constellation recognition, where to buy and how to use a telescope, the life and death of stars, including of course, black holes, and a few other things like the search for life in outer space and of course, how to watch a UFO. This two-hour class, called “Exploring Stars and Planets,” will meet at the Planetarium on the Fort Pierce campus of Indian River State College, and it will begin next Wednesday, May 8 at 6:30 p.m., and continue through mid-June. The catalog number is AST 1930, and as I said, the instructor is me, Jon Bell. Oh, we’ll see a lot of planetarium shows too! You can register online or at any of the College’s registration centers. Once again, that’s “Exploring Stars and Planets,” AST 1930, and it starts next week.
Fri May 3, 2019 ETA AQUARID METEOR SHOWER The Eta Aquarid meteor shower is at peak activity the next two nights. These particular meteors are bits of dust from Halley’s Comet, plunging into our atmosphere, where they are vaporized, heating up the air around them and causing that momentary streak of light you see in the night sky. Most meteor showers are best after midnight, and this one is no exception. Last month’s Lyrid meteor shower was spoiled by bright moonlight, but the moon is now nearly new, and won’t interfere with the display. If skies are free of interfering clouds or streetlights, face east and look up toward the top of the sky. Dress warmly, protect yourself against mosquitoes, get away from the bright lights, and use a lounge chair so you can recline and enjoy the shower. Meteor showers are not like fireworks displays – sometimes you can go for an hour and not see anything; but every so often, you’ll be rewarded by the appearance of a streak of light in the sky, a shooting star or meteor.