Greetings Fellow Star Gazers!
Welcome to the second edition of Star Gazing Guide from the Milky Way Cowboys at Bare Dark Sky Observatory (BDSO). Hopefully, many of you ventured outside this past week and enjoyed an evening under the stars with friends or loved ones … maintaining social distancing protocol, of course. We truly miss being with you as you share your passion for all things astronomy and we hope to meet up with you soon at our observatory.
We have once again included the link to The Evening Sky Map. Besides giving you a map of the northern hemisphere night sky, this is a wonderful tool to learn astronomical vocabulary and what celestial objects are easily visible to the naked eye, binoculars, and telescope in April.
So let’s get to it. Over the next several days, our favorite and closest star, the Sun, will be setting around 8 pm. The waning moon won’t be much of a factor unless you’re out past midnight. Your first stars should be showing themselves by around 8:40 pm. As you watch Orion the Hunter making his stately appearance, test your memory on what you learned last week. If you can recite the names of his belt stars, feet and shoulder stars, and the stars and their constellations that make up the Winter Hexagon, without cheating, let us know and we’ll mail you a Milky Way candy bar!
If you look over to the west you can’t miss Venus, the second brightest object in the night sky after the moon. Some Venus fun facts: This second planet from our Sun is just a tad smaller than Earth and was named after the Roman goddess of love. It has no moons. The atmosphere is about 96% CO
2
—a runaway greenhouse effect—while the rest is mostly opaque clouds of sulfuric acid. Yikes! If that isn’t bad enough, the atmospheric pressure is a hundred times greater than Earth’s. So imagine having 1500 lbs pressing down on you. If you can survive that, you wouldn’t survive the temperature which cooks constantly at around 870
o
F. Venus is one of two planets that spins clockwise (Uranus the other). What is really fascinating is that a Venus day takes 243 Earth days, but it revolves around the Sun in only 225 Earth days. In other words, a Venus day is longer than its year! Enjoy her while you can because Venus will disappear from our night sky by the end of May.
Do you see that small cluster of stars in the same area of the sky as Venus? Meet Pleiades, also known as the Seven Sisters and Messier 45. (We’ll talk about Charles Messier in a future session). Pleiades (in Tauras) is about 444 light years away, meaning that photons of light have traveled 186,000 miles a second since the late 1500s and are just now reaching your eyeballs. How many of the sisters do you see? Most people see six, however, the cluster contains some three thousand stars. In Japan, Pleiades is known as Subaru and was the inspiration for the automobile company’s name and logo which depicts six stars. If you look at Pleiades through your binoculars, you can enjoy several hundred stars, and even more through a telescope. If you do a search of Pleiades you’ll find a plethora of fun legends and stories, especially by Native Americans. They range from Kiowa princesses being chased by bears, to Mono tribe wives being cast up into the heavens for loving their cooked onions more than their husbands. The Old Testament book, Job, twice chronicles the magnificence of Pleiades along with Orion. Enjoy the Seven Sisters while you can before they soon disappear from our spring night sky.
Moving on here … look to the north and locate the Big Dipper. We mentioned last time that the Big Dipper (called The Plough in the UK) is an asterism (familiar pattern of stars) and is the tail and body of the Great Bear (Ursa Major). You definitely want to check this out in a sky app to get the big picture. If you draw an imaginary line through the two stars on the front of the dipper’s cup, Dubhe and Merak, following the line will point to Polaris, the North or Pole Star. Polaris is the end of the handle in the Little Dipper (Ursa Minor). As a memory aide, we affectionately call these pointer stars the Dubhe or Doobie Brothers. Are you surprised that the North Star isn’t brighter? There are at least 45 brighter stars. However, for thousands of centuries travelers on land and water have depended on the North Star as a dependable guide to get them home. Even though Polaris is 434 light years away, it is actually about fifty times larger than our Sun. As a side note: most people do not know that Polaris has not always been our
only
North Star. More on that in a future session.
Some of you have asked about Comet Atlas which is currently on a near-parabolic orbit around our Sun. It is currently visible at around 7 magnitude, easily seen through your binoculars or a small telescope in the constellation Camelopardalis, which is near the Big Dipper. We’ll discuss magnitude (brightness) in a later session. As Comet Atlas closes in on the Sun in May, the tail will begin to stretch out more and always point away from the sun. It will cruise thru Perseus and become visible to the naked eye (less than 6 magnitude). Some astronomers believe it will become as bright as Jupiter, and hopefully, brighter than Venus. That would be a sight to behold!
As we close this session, we want to remind you that the Lyrid meteor shower will peak around April 21 and 22. Unfortunately, the best viewing will be after midnight at 3:00-5:00 am with an estimated 20 meteors per hour. Although the Lyrids appear to generate out of the constellation Lyra, meteors may appear in any part of the night sky all evening long.
Next week we will talk about the other past and future North Pole Stars, how to tell the difference between stars and planets, plus showcase some more spring constellations.
Also, look for a Special Session of “Two Guys and a Telescope” when we share some basic astronomy terminology and get a bit deeper, but not too technical. Stay tuned …
