The constellations overhead in May are dominated by Leo and Ursa Major. Leo the Lion is easily picked out by a large backward question mark known as the Sickle. The bright star at the bottom of the Sickle is Regulus. Ursa Major the Great Bear is home to the well-known group of stars known as the Big Dipper. The handle of the Big Dipper curves and points to the bright orange star, Arcturus. Arcturus is the bright star in Bootes that resembles a kite or ice cream cone. If you continue the curve from the Dipper’s handle past Arcturus, the next bright star you will see is Spica – the brightest star in Virgo. The winter constellation Gemini is found standing upright over the western horizon. Cassiopeia looks like a “w” on the northern horizon. To the east of Bootes there is a small dim “c” of stars known as Corona Borealis and then east of that you’ll find the large but not very bright constellation of Hercules. The Milky Way in May is hugging the horizon from the east to the north ending up on the southwest horizon.
The Eta Aquarids meteor shower peaks at about 4 a.m. Tuesday, May 5 and can average about 10 meteors per hour, but this year will compete with an almost full moon.
Comet Atlas, which I told you about last month, has fragmented into several pieces and is currently fading, so we probably won’t be able to see it with the naked eye this month. However, a newly discovered Comet Swan may reach naked eye visibility in late May, and I remain hopeful we will see a nice comet this month.
A nice planetary conjunction is visible May 21 in the west/northwest about 30 minutes after sunset when Mercury and Venus are about 1 degree apart.
Be sure to check out Betelgeuse early this month before it slips over the western horizon – it is almost back to its usual brightness.
If you’ll look to the south this month, about halfway between the horizon and zenith, you’ll see a dazzling white star. That star is Spica, the brightest star in Virgo. Virgo contains mostly dim stars and is best described as a meandering open “y” shape.
Looking towards Virgo gives us a chance to peer deep into the universe because we are looking up and out of the flattened disk of our galaxy. If we could “see” what lies in that direction, we would see everything from some of our closest stars to thousands of galaxies all the way out to the edge of our universe.
First, we would see two of the stars closest to the Sun – Ross 128 and Wolf 424 – that are the 11th and 28th closest star systems. Both stars are small, cool stars known as red dwarfs. At 35 lights years away, we’d see Porrima, which telescopes reveal to be a double white star system of almost equal color and brightness. Continuing several hundred light years away, you’ll find Spica, the 16th brightest star in our sky. Spica is a white giant star thousands of times more luminous than the sun.
At about 1,000 light years, we reach the upper edge of the disk of our galaxy and we are looking at intergalactic space.
As we look out in space past our galaxy, we are looking at a massive collection of galaxies known as the Virgo Coma Cluster of galaxies lying 30 to 50 million light years away. This cluster of galaxies has thousands and thousands of member galaxies. One of the outlying and closest galaxy of the Virgo Cluster is the Sombrero Galaxy. This splendid galaxy is an almost edge on galaxy that looks like it has a sombrero brim made of dark dust lanes.
Past the Virgo Cluster of galaxies at 3 billion light years we’ll find 3C 273, which is the brightest quasar and can be found in reasonably-sized telescopes. Quasars are the most energetic objects in the universe.
As we continue another 15 billion light years we reach the edge of the universe.