Skywatch for the week of June 14, 2021
Mon June 14, 2021 FLAG DAY
Today is Flag Day. On this day in 1777, our national flag was adopted by the Continental Congress, which also on this day established the U.S. Army. The flag held thirteen stars, one for each of the original colonies; and of course, the current U.S. flag has 50 stars, one for each state in the Union. The arrangement of stars on flags does not as a rule correspond to any actual constellation in the sky, and the U.S. flag has gone from a circle pattern to a series of rows and columns, and of course there was even an arrangement where the stars were made into a great star image, such as the one that flew over the fort in Fort Pierce when it was built back in 1838. Sometimes the stars on flags do reflect actual star patterns, such as the use of the Big Dipper and the North Star in the state flag of Alaska, or the use of the Southern Cross in the flags of Australia and New Zealand; and Brazil’s flag features the Southern Cross, Canis Major and Scorpius.
Tue June 15, 2021 NAME THAT CONSTELLATION - JUNE
Of the eighty-eight officially recognized constellations, can you identify the thirty-first largest one? It is bordered on the north by the constellation Lynx the Bobcat, and on the south by Hydra the Snake, on the west by the Gemini, and on the east by Leo the Lion. There are no bright stars here, and it is one of the darkest regions in the night sky. But there is a beautiful open star cluster within its borders, known as the Praesepe or Beehive cluster, and some of its stars have been found to have planets orbiting them. In mythology it was a crustacean that was sent by the goddess Hera to attack the hero Hercules. It was accidentally crushed by Hercules during the fight, but Hera restored it to life in the heavens as a constellation. Tonight the planet Mars is within its borders, while the waxing crescent moon lies to the east of it in Leo. Can you name this star figure, the third constellation of the Zodiac? The answer is Cancer the Crab, high in the south after sunset.
Wed June 16, 2021 VEGA IN THE EAST – VULTUR CADENS
As darkness sets in this evening, look toward the east. There’s a bright star over there – its name is Vega, and it’s the fifth brightest star in the night sky. The name of this star comes from the Middle East, and translated it means, “falling, (or “swooping,) eagle (or vulture)”. Vega and the stars around it form an ancient star pattern known as vultur cadens, which also means, “falling vulture,” although the official constellation here is Lyra, the Harp. On star charts you can sometimes see it pictured as a vulture with a harp inscribed within it. Above Vega are some fainter stars which trace out a simple letter H. The H stands for Hercules, and for his sixth labor, this mythical Greek hero fired arrows at this vulture, and also at two nearby constellations, Cygnus the Swan and Aquila the eagle, driving them away from Lake Stymphalus, where they had picked up the unfortunate habit of swooping down and attacking any unsuspecting people who wandered by.
Thu June 17, 2021 WILLIAM PARSONS, LEVIATHAN BUILDER
Sir William Parsons was born on June 17th, 1800. Forty years later, he built the Irish Leviathan. At sixteen tons, and with a primary mirror six feet across, the Leviathan would remain the world’s largest telescope for the next seventy years. It was so big that it couldn’t be rotated, so by leaning the instrument east to west, Parsons could observe objects for over a half hour. The Irish Leviathan was so powerful that he could actually see individual stars in distant galaxies like M51, the Whirlpool, roughly 40 million light years away! A lot of the colorful descriptive names of nebulas and galaxies were made up by Parsons – the whirlpool galaxy, the crab nebula, the Saturn nebula. After Parsons died, his son continued his work, but his grandson had no interest in astronomy, and Leviathan was dismantled, its metal supports melted down for ammunition during the First World War. But it was rebuilt in 1999.
Fri June 18, 2021 ANCIENT SUN TEMPLES
Stonehenge was built over forty centuries ago; it’s one of over a thousand circles of standing stones that can be found throughout the British Isles and Europe. On the first day of summer, the sun rises over an outlying heelstone, as viewed through a central arch of stones. Other old observatories around the world mark the sun’s seasonal positions. In ancient Egypt, temples were built so that at the summer solstice, the sun’s rays shone through tall columns to sanctuaries within. At the Bighorn medicine wheel in Wyoming, piles of carefully placed stones pointed toward the summer sunrise. For hundreds of years in New Mexico, a slender ray of sunlight – the sun dagger of the Anasazi – sliced through a petroglyph spiral on the first day of summer. And there is the Sun Temple, built by the Incas at Machu Pichu – but of course Peru is south of the equator, and now it is the winter solstice sun that is framed in this ancient observatory’s window.