Stellar Vista Observatory Sky Report
John Mosley
May 16 – 22
The Sky Report is presented as a public service by the Stellar Vista Observatory, a nonprofit organization based in Kanab, Utah, which provides opportunities for people to observe, appreciate, and comprehend our starry night sky. Additional information is at www.stellarvistaobservatory.org. Send questions and comments to [email protected].
When the moon, which is one day past full, rises at roughly 10 pm. on Monday it will be 2½ degrees from the bright red star Antares, the heart of Scorpius, the Scorpion. This is the closest that the moon will come to so bright a star this year and you’ll see the two together in any binoculars, separated by five moon-diameters.
Antares is an interesting star. It’s one of three orange stars that are bright enough to see their color (the others are Aldebaran and Betelgeuse); binoculars help bring out the color. Antares is about 550 light-years distant and it’s a giant star about 100,000 times as luminous as our sun; if placed at the center of our solar system its surface would extend beyond the orbit of Mars.
Antares is an evolved, old super-giant star that has swollen as it approaches the end of its life, and one day, perhaps within the next hundred thousand years, it will explode as a supernova; then it’ll rival the full moon in brightness for several months.
Scorpius is one of the oldest constellations and these stars have been called a scorpion for least 6,000 years. People in the Middle East were very familiar with scorpions, and it’s easy to see this pattern of stars as a scorpion, as you’ll see once it has risen fully. The path of the sun, moon and planets passes through the very topmost part of Scorpius and occasionally they pass near Antares.
At this time of year at this latitude you can see the very southern constellation Centaurus low in the south at about 10 pm., or at least you can see the top part of it. Centaurus is one of two centaurs in the sky, the other being Sagittarius.
In Greek mythology centaurs, half-man half-horse were a wild and rough lot best avoided, but Centaurus was a specific centaur, named Chiron, and he was a gentle soul – a teacher famed for his wisdom and his knowledge of medicine. You’ll find a good star chart – plus many other good things – at www.heavens-above.com (customize for your location).
There are no planets in the evening sky but there are four in the morning. Venus is unmistakable, but it’s very low, only about 10 degrees above the horizon and due east 45 minutes before sunrise. Jupiter is almost as bright, and it’s almost 20 degrees to the west, or upper right, of Venus. Mars and Saturn are fainter and farther to the west. Mars is about 6 degrees to the right of Jupiter and you might see both together in wide-angle binoculars.
Watch Mars approach Jupiter day-by-day and estimate when they will be in conjunction; a nice one is coming up soon. Mars passes only ½ a degree below Neptune on Wednesday and you can see them together in a telescope on low power but Neptune is probably too faint for your binoculars. Remember that your fist held at arm’s length spans about 10 degrees.