Download Observing

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
• Refractor
– 6 inch (15-cm) achromatic lens
24-inch
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)
6-inch
What to observe?
A BL Lac Object
• BL Lac objects are one of the family of
active galactic nuclei, a group which
includes quasars and Seyfert galaxies,
among others
Long term light curve
Makarian 421
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