Astronomy in UP




An Elusive Beauty

Though I had observed Cor Caroli (STF 1692) many times in the past, a few years ago I found myself in the middle of an observing project in September and there it was on my list. Given my perpensity to finish what I have started, I was determined to observe it again. However, given the time of year, I knew that it would be impossible from my observatory; it would take a low western horizon and twilight. I knew just the place! Starting in Munising bay and extending some thirty miles east along Lake Superior is "Pictured Rocks", a series of rock cliffs rising from the lake to a height of 150' to 300'

From this standpoint, I would have a chance. I took up position a few miles from town on the east side of the bay looking west and waited. Arcturus, Deneb, Vega and Altair signaled the approach of twilight. There were whitecaps on the bay, some 165 feet below and with nothing between me and Canada nearly 287 miles to the north, I could feel the north wind biting at my ears and cheeks. Next came Alkaid, Mizar and Alioth and I knew Cor Caroli would soon follow. There it was, about 25 degrees above the horizon. Under the right circumstances, an easy prey.

Observation/Notes: Using an 80mm f/15 refractor and a 10mm ortho eyepiece for 120X, the pair separated into a yellow-white primary and a pink-blue secondary. What a striking couple - even in the low altitude, which no doubt affected their glory. Flammarion gives "yellow of gold & lilac" and calls the pair "Superb". He refers to Alpha CVn as "Le Coeur de Charles", "The Heart of Charles" and attributes the name to Halley.

Olcott, in his book "In Starland with a Three-Inch Telescope", gives both components yellow and says this: "7 degrees north-northwest of Cor Caroli is "La Superba", a 5th magnitude star of brilliant red color. It is one of seven or eight naked eye stars of 4th spectral class and is noted for the brilliant coloring of it's flashing rays" (in the hazy atmosphere at this low elevation, I could not pick out this red companion star). Couteau called it "one of the prettiest doubles in the sky" and suggests to" look at it with a small telescope." The pair was an easy observation with my 3 inch.



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