One nighttime observing project is required in this semester's AST 142. There are two projects from which to choose.

For both of these projects, we will be using CCD cameras on the 24” telescope at Mees Observatory. The observations will commence as soon as the departure of winter weather makes it possible, probably late March to mid April. Naturally, this will all take place outside of class time, and needs for the sky to be clear (preferably cloudless and moonless), so a good deal of schedule flexibility and spontaneity will be demanded. Please read the article on report format, to see what the expectations are for these reports, and to see the level of detail and analysis that should be recorded and carried out for the project.

The C.E.K. Mees Observatory is located near Bristol Springs, about an hour’s drive south of campus. We will carpool to get there.

Here are your choices: a classic experiment, or a classic observational feat.

1. RR Lyrae stars and the distance to the globular cluster M3

Two 15-minute color images of the globular cluster M 15, taken about 1.5 hours apart and blinked once per second.
Click the picture for a larger version, and see how many variable stars you can count. (Mees Observatory image.)

Some of the members of globular stellar clusters have periodically-varying brightness which is characteristic of each star's luminosity. If this luminosity is known, a measurement of each star's apparent brightness comprises a measurement of the distance to the star cluster: a simple application of a standard candle.

2. The Messier Marathon

    

Messier 1, a.k.a. the Crab Nebula, in Taurus (left); and Messier 109, in Ursa Major (right). (Mees Observatory images.)

In an effort to warn other comet hunters of fuzzy patches in the sky which are not comets but could be carelessly mistaken as such, Charles Messier collected and characterized a catalogue of  objects which turn out to include the brightest nebulae, star clusters, and galaxies. Under clear and dark (moonless) conditions at the end of March and beginning of April, it is possible to observe all 110 objects in Messier's catalogue in the same night. There are many amateur astronomers who have observed the whole list in a single night using small, non-automated telescopes and their own eyes, so it should be easy to do this with a computer-controlled 24" telescope and a CCD camera, right? (Those amateurs are laughing already...)