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Notes from the telescope- June 2012

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SXN
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Joined: 2010-03-12

Last night was one of those rare nights that become like legends as time passes, and you tell the stories of the "the night when..."

It has been oppressively hot and humid here all week. Temperatures in the 90's (F) with high humidity. Monday night it was still 80oF when I opened the dome at 11PM. It was actually hot. It's pretty rare for me to observe in shirt sleeves, but it has been short sleeve shirts and lots of bug repellant all week long. Last night was much cooler and drier. I was happy to put on a hooded sweatshirt and carry my coffee and clipboard out to the observatory to prepare for a comfortable night at the eyepiece. The fair weather puffy clouds from the afternoon were breaking up and giving way to mostly clear skies, with just a few remnants of clouds slowly passing from west to east.

I decided to begin the night covering my LPVs in Boo and CrB, so I pointed to Z Boo first. As luck would have it the first star of the night was near minimum and I had to go to high power (243x) to dig it out of the still slightly twilight sky. I found it surprisingly easy, once I considered how faint it actually was. I was able to see the 145, 147 and 151 comps easily, and to my surprise I was catching glimpses of the 155 comp out of the corner of my eye whenever I looked directly at the 147! That was my first clue as to how good the night was going to be. 15.2 is my typical limiting magnitude here on an average night with no moon.

Most of the rest of my LPVs for the night were 11th or 12th magnitude, and a couple were brighter than 10, so I observed them with the 80mm refractor mounted on top of the 12" LX200. X CrB was the only other semi-faint LPV I attempted this morning. I estimated it to be 13.8, but would have like to have had a star to fill the unfortunate gap between 138 and 147. (Hey, who's in charge of this stuff?) I'll be looking in SeqPlot today to see if APASS data can fill the hole with a nice 142 or 143 comp. I made a note that I could easily see the 154 comp.

It went on like that all night until I finally wore out around 2:30AM. While observing CVs in Boo a short time later, I actually reported a <16.1 observation. In my notebook I simply wrote, "Wow!!" Mid to upper 15's were the norm all night long. I had to hunt for fainter comps than I usually use on almost all the CV fields I observed because my "go to" stars, typically 148-152, were all so easy to see. I have high hopes for tonight, so I'm going to make a point of getting plenty of rest so I can go until dawn makes me cover the telescope tube.

Those of you along the coast east of me are probably going to inherit this perfect weather tonight. Don't miss it.

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484