Teachers learn how to use digital cameras to unlock views of constellations and more
May 14, 2011By Richard DeCoster and Margie Corp for Stars at Yerkes News
How can you see a satellite with a digital camera? The answer is found in the science of astrometry. At the final Stars at Yerkes workshop of the year, teachers examined this along with a new view of their constellation photographs previously taken.
Contributing Stars at Yerkes scientist Richard Kron had introduced teachers to this program at the AAS meeting in Seattle last January. Since then, Rich and Elizabeth worked to see what great things could be done with the program. Kron added to the discussion by giving some background on the development of the program and some of its features. Our participants readily took to this program and sent about twenty pictures to the service to be identified. Most had amazing success and were quite pleased with their results.
Elizabeth Ramseyer and Rich DeCoster work with images using astrometry.net
Astrometry illustrated using a simple constellation photo.
Professor Kron delivered a wonderful talk on geostationary satellites. He identified some of the interesting aspects of these satellites and discussed the distinction between “geostationary” and “geosynchronous.” He discussed the location of these satellites and showed us where one should aim his or her camera to find one. The images he showed of these satellites were quite amazing. The idea is that the satellites are orbiting with the same period as the 24-hour period of Earth and thus appear to stay in the same spot with respect to an Earth-bound observer. But the stars are truly stationary and thus appear to move with respect to this same observer. Kron’s ~100 second exposure revealed an image rich the streaks that corresponded to the stars and with a series of dots, not streaks, that were the satellites!One interesting aspect was that even though these satellites follow orbits that suspend them exactly over Earth’s equator, from our location they do not appear among the equatorial stars. Due to the phenomenon of parallax, they appear to like some angular distance below the equator, the exact distance depending on the longitude of the observer.
Satellites appear as stars and stars look like streaks in this photo by Rich Kron.
Rich Kron was at his best in explaining to us numerous projects, including student projects, that could be developed that utilize aspects of the observation. But the amazing feature of the presentation was the beauty of his image, with the little dots beading along an image otherwise filled with many stellar streaks.
Vivian talked about this cataclysmic variable, and how she was mentored in its study by Janet Mattei, long-time director of the American Association of Variable Star Observers (AAVSO). Over the past decades, Vivian has taken many images of this star and prepared numerous educational outreach activities based on the analysis of these images. As a long-term goal, Vivian is trying to understand some of the more subtle aspects of the variations that she has recorded for this star, including how the light output from the star varies at different colors or wavelengths.
Vivian Hoette discusses variable stars with in-person and virtual participants.
Josh Haislip presented this via Skype from North Carolina. With help from ARCS teacher Kevin McCarron and Vivian, Josh walked us though the procedures to make a light curve. This was a follow-up to our April workshop that featured the use of the Skynet system and its light-curve producing capabilities. Josh is continuing to develop additional aspects of the program. It was really cool to see how easy this process was, once the series of files was properly prepared. For practice we created a light curve for a supernova that was caught early on in its explosion, while the object was still getting more luminous.
Stars at Yerkes scientist Al Harper joins the group discussion on Skynet and SOFIA.
Vivian Hoette and ARCS teacher Kate Meredith assist virtual participants.
Our calendar of workshops for next year will be posted August 2011. Please check with us then for information about more exciting learning opportunities with the teachers and staff of Stars at Yerkes. Happy Summer!