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Observing. Next Tuesday. We’ll meet at the observatory even if it is cloudy If the weather is really bad (a foot of snow or something) I’ll send an email changing the meeting place, but otherwise…. Observatory location. Observatory Location. Telescopes. Reflector 24-inch (60-cm) mirror
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Next Tuesday • We’ll meet at the observatory even if it is cloudy • If the weather is really bad (a foot of snow or something) I’ll send an email changing the meeting place, but otherwise…
Telescopes • Reflector • 24-inch (60-cm) mirror • Refractor • 6 inch (15-cm) achromatic lens
Ritchey-Chretien • A special kind of cassegrain telescope • Gives good wide field images (but our CCD field of view will be limited to 11 x 11 arcmin)
BL Lac objects are one of the family of active galactic nuclei, a group which includes quasars and Seyfert galaxies, among others
Reading assignment • Read the section on Makarian 421 on the AAVSO web page • Check the web/library for further info on BL Lac objects • Give me (at the next class) a one page writeup on what is believed to cause the brightness changes of BL Lac objects (be sure to express this in your own words)
Other possibilities • Galaxies
Star Clusters • M67
Gaseous Nebulae • M42