Thursday, April 26, 2007

Yerkes Observatory trip

The Ryerson Astronomical Society sponsored a trip up to Yerkes Observatory this weekend. We split the 60-odd visitors into three groups and showed them the observatory through twilight. I got to show them the basement and the 24-inch reflector--fairly mundane things, and there is only so much you can opine about the difference between astronomy and astrophysics three times in a row. So, while talking about the infrared camera called HAWC on the second-generation flying telescope called SOFIA, scheduled for its first test flight today!, I tried my best to talk about light outside of our visible range. And I had to bring up near-infrared radiation and took some examples with each group. The above image is from the next morning. Everyone hopefully had fun looking through all the scopes, including the world's largest refractor, at various targets. Halfway through the observing I moved the 24-inch onto Messier 51, the spectacularly interacting galaxy pair in Canes Venatici, just off the handle of the Big Dipper. I would say some two-thirds or more of the visitors saw the spiral arms. After the big group left, the overnighters returned to the 24-inch at as M51 was transitting, the arms were much more evident.

(An example from Ryerson Observatory of M51).


Jennifer said...

Do the tree leaves look white in IR because they're emitting or reflecting? Or am I way off the mark completely?

Dean W. Armstrong said...

They reflect near-infrared light really well, due to their cellular structure. See Plants in the near-infrared for a discussion.