MB report Wed 5/29
by Glenn Hirsch
Silicon valley hikers, and bikers, some nice Russians, a few teenagers and their hippy mom, all flood the parking lot. The day shift of nature lovers meets the night shift. They gather 'round as in the twilight first Venus and then Jupiter appear. "Something special happening tonight? Are the planets always line up this way? Why do they appear one-by-one? Why is Jupiter striped?" To me amateur astronomy is not as much about real science as it is about loving Nature. And Nature lovers love to share Nature. "Amateur" originally meant someone who loves.
Venus and Mars lie close together, tonight Mars is completely dominated by the brilliant goddess, near Jupiter in the heart of Gemini. Pollux, Castor and the two bright planets form a new "constellation." In the East, Antares ("anti-Mars") rises and it too defeats tiny Mars. For fifteen minutes my eye is glued to Io until it finally disappears behind Jupiter's limb at 920pm. Given that most everything in the heavens occurs in glacially slow "star time" -- in which a 10 million-year-old star is considered to be "young" -- it's thrilling to see Io disappear from 400 million miles away! Io is about the size of our Moon moving at 30,000 miles/hour, zooming around in its 1.3 million mile orbit in under 2 days! Jupiter is just slinging that sucker around! (Thanks to Paul Lawrence for this info.)
By this time Leo and Cancer take a nosedive for the horizon and M44 hangs suspended like a mobile of metallic balls floating passed us at 520 light years. It's the second oldest cluster in the sky, these 200 stars were born together 10 billion years ago and no one knows why they never left each other. I can see triple star ADS 6916 at the point of a "v" asterism inside the cluster; and quadruple orange star ADS 6921 higher up.
Scorpius snakes out of the ground and rises with the point of it's arrow marked by Delta Scorpii - a giant star which has doubled in brightness in just the last 24 months (from magnitude 2.3 to 1.6). At 500 light years, it radiates 70,000 times more than the Sun. Delta Scorpii is a "B-e star" ( "e" standing for "emission"), also known as a Gamma Cas variable which is fairly common and weird. They rotate at 300 kilometers per second at the equator, 150 times the solar rate. The rotation and high luminosity drive mass from the star into a surrounding disk, radiating X-rays and causing flare-ups in brightness. Two years ago Delta Scorpii was the exact same brightness as nearby Beta Scorpii -- but not now.
Then to explore the southern sky as it peaks above our horizon only in May and June. Constellation Centaurus has many bright and unfamiliar patterns, as does nearby Lupus, the Wolf. To the Greeks this region was simply known as "The Beast" or "The Animal." Nice swirling patterns though. Finally staring straight up for an hour to find some goodies overhead. I star-hop to find red dwarf Lalande 21185 again. Then M97 the Owl Nebula, in Ursa Major but it's just a smudge in this not-so-transparent and increasingly not-so-dark sky. A giant lop-sided, smeared and sickly yellow moon rises at midnight.
When I visited the cathedrals of Italy I got what my wife called "chapel neck," caused from constantly staring straight up with your mouth open. Chapel neck again tonight.