By CAROL LUTSINGER
May day is a great day to leave a basket of blossoms on a neighbor’s front door. This old English tradition used to be continued in this country up until the 1960s, I think. The longer hours of daylight and warmer temperatures have brought an abundance of bright yellow Palo Verde blossoms along the Valley roads all up the highways to San Antonio. If you are wondering about the astronomy connection, well the sun is part of astronomy, as is our home planet. I am sneaky that way.
As the world turns to another month, we will be entertained royally with the pageantry in our Valley skies. If you have developed an enthusiasm for stargazing, you may be ready to keep a list of “trophies,” much as birders do. A small notebook to record your viewing highlights will offer a broad spectrum of celestial specimens. If you are interested in having a Scavenger Hunt list of suggestions, one is posted with the South Texas Astronomical Society’s website.
The clear mild May evenings make a great time for family adventuring in sky watching. Look for the Milky Way to lie along the horizon in the direction of Virgo and think about the fact that you are looking out of the plane of our galaxy! Now that’s a mind-boggling experience. Earth is standing straight up and down in our galaxy, parallel to the axis.
Look for Boötes, the kite-shaped constellation in the eastern sky, which contains Arcturus. Now track just below and left of golden Arcturus. Do you notice a semi-circle of stars there? This is the Corona Borealis. Hercules is just below and left of it. Hercules is shaped roughly like a cornerstone, or trapezoid, with “arms” of stars extending out from each corner. If you visit a neighbor who has a telescope, this is where you may spot a real trophy, M13.
What’s M13? I thought you’d never ask! It is the brightest globular cluster on the northern skies. A globular cluster is a loosely-formed grouping of stars that is just a glob, not a defining pattern. Seen through a decent telescope it is a breathtaking sight. In 1784 a French astronomer, Charles Messier, compiled a list of fuzzy objects that he saw in the sky and gave them each a number so that he would not be confused when he was searching for comets, which are also fuzzy appearing. They turned out to be fascinating deep sky objects; amateur astronomers enjoy having contests to see who can spot the most Messier objects in one session. “Bagging” the most Messier’s is a BIG deal, and May is a perfect time to go hunting for these dim, distant objects outside our galaxy. Perhaps you could do that at the end of the month with the night hike at the Resaca de la Palma state park’s last Friday of the month event.
Our winter companions, Orion and his colleagues are lower in the western sky and will soon be leaving for a while. They will be replaced with Vega, Deneb, and the other summer stars which shine during the summer nights, giving the fireflies a run for their money; more about these stars and their constellations later in the month.
All these stars appear to rise in the east and set in the west, as does our star, the sun, because the Earth rotates on its axis from west to east. This makes the Big Dipper asterism a circumpolar constellation, that is, it never sets, just rotates about Polaris, the North Star.
Until next week, do let some stars get in your eyes.
