New Radio Astronomy Lab Course Yields Big Results

Nov 29, 2012

Professor Snezana Stanimirovic with four Astronomy 510 students in front of the 2.3-meter Small Radio Telescope (SRT) on the roof of Sterling Hall. From left: Paul Sell, Stanimirovic, Nick Pingel, Al Lawrence and Matt Huang.

You may have wondered about a small black radio dish on the roof of Sterling Hall. It is the latest addition to the array of telescopes operated by the Astronomy Department—a 2.3-meter radio telescope that scans the sky over a range of frequencies from 1400 to 1440 MHz and provides hands-on experience for students in Astronomy 510, the department’s new Radio Astronomy Laboratory course.

Professor Snezana Stanimirovic received the Cottrell Scholar Award from the Research Corporation for Science Advancement in 2009 for her research and educational work, with part of her proposed work being to develop telescopes and curricula in radio astronomy for Wisconsin students.

The radio dish is the first of three Small Radio Telescopes (SRTs) purchased from the MIT Haystack Observatory. The SRTs emphasize UW-Madison’s long tradition of radio astronomy, going all the way back to the “father of radio astronomy,” Karl Jansky, who was a UW physics undergraduate.

The first SRT was put together by Rick VanDer Geest and Rick Williams in the department’s electronics shop. First light was achieved last December, and the telescope played a central role in the spring upper-level Radio Astronomy Laboratory course. The course covers the fundamentals of radio antenna theory, calibration and observing methods through a combination of lectures and hands-on observational experiments.

Undergrad and grad students Matt Huang, Al Lawrence, Nick Pingel, Paul Sell and Anna Williams first observed the Sun in order to measure basic telescope properties—beam shape and noise properties. In later labs, the students measured the height of the neutral hydrogen (HI) disk and the rotation curves of the Milky Way. “Everyone was very excited to be able to run the telescope and collect data from the warmth of a classroom in the midst of a blizzard on a cold wintry day. We compared our SRT observations with published data and in most cases got excellent agreement,” says Stanimirovic. “It’s exciting to have a very small telescope work so well and obtain HI spectra comparable to what has been achieved with professional telescopes.”

Left image: Galactic rotation. This curve shows the distribution of gas velocities in the galaxy measured by the Sterling Hall "Small Radio Telescope" Array (SmaRT).

This summer, one of the Astronomy 510 students, Al Lawrence, a returning undergrad with an electrical engineering background, worked with Rick VanDer Geest in assessing the best location for the second telescope. Because of the radio interference on campus (TV and radio stations and cell phones), they decided to place the telescope at the Pine Bluff Observatory. Construction will be completed this fall, and students will have remote access to it.

The third SRT is on loan to UW-Milwaukee and is being developed by physics professor David Kaplan for his students. While all three telescopes are now being used independently, the long-term goal is to connect their signals and create a small radio interferometer similar to the Karl Jansky Very Large Array in New Mexico.

While the SRTs are currently being used only for upper-level classes, future work includes the development of tutorials for introductory astronomy classes. Non-science majors will then be able to obtain HI spectra of the Milky Way and explore important concepts (Doppler shift, rotation curve and dark matter) in a hands-on environment and gain an understanding of the process scientists use to create knowledge.

With more telescopes on board, one important task remains—naming the department’s SRTs! We invite your suggestions. Please submit them to Professor Stanimirovic at sstanimi@astro.wisc.edu.

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