As two students taking astronomy at John Abbott College, we assumed most of our course projects would be theoretical or use second-hand research. As such, we were happy to get a hands-on opportunity detecting an exoplanet using The RASC’s Robotic Telescope.
To observe the exoplanet we used the transit method, which identifies a dip in the apparent magnitude of a star. This drop would mean that a planet crossed — or transited — between the Earth and the star. With the support of our RASC mentor Jenna Hinds, we tackled this project in four steps.
We first needed to select a candidate star to observe. Searching a database from Swarthmore College, we found a handful of targets, HAT-P-16b being our final choice.
After selecting the target, the transit needed to be observed and recorded. We used The RASC Robotic Telescope in California. On October 23, 2019, Hinds recorded a sequence of 480 images taken on a monochromatic camera.
The raw data was noisy, shaky and flipped at the end due to “meridian flip,” a switch in image orientation caused by the telescope crossing its vertical axis. Using AstroImageJ, an open source astronomy software, we were able to correct all of these issues and prepare the data for analysis.
Using AstroImageJ once more, we performed multi-aperture photometry: the comparison of the relative brightness of stars across the sequence.
Originally, the scope of this project was overwhelming; we had minimal knowledge on how to gather and analyze this data. Hinds provided us with a library of video tutorials, making each step clear.
In the end, we didn’t just analyze information found online. We produced our own data and conducted research based on it. This task quickly became something we genuinely wanted to succeed.
We would definitely recommend this project to any students who enjoy astronomy and would like to delve into its modern applications. While the task may initially seem daunting, being guided when needed can improve the process to make it not only a learning experience, but a truly unforgettable and enriching one.
The blue plot is HAT-P-16b. Other plots are other stars used as controls. As predicted, a noticeable dip was found in our target star. In other words, the presence of an exoplanet is likely. The last bit of analysis we did was adding a best-fit curve. Using this curve, we found an experimental transit depth of 11.1. The value indicated on the database was 11.5.
— By Chelsea Taiger and Kristofer Karam
