Confirming a Kepler Object of Interest (KOI) Exoplanet Using the Sierra Stars Observatory Network

Nathan Kirse and his academic advisors for his astronomy research project contacted me at the end of August 2015 to ask me if it was possible to detect a relatively faint transit of a possible exoplanet using one of the SSON telescopes. After discussing what the requirements were for the project we determined that we should be able to meet the goals of his project. However, this would not be a typical schedule request for a SSON job schedule. The project would require taking hundreds of contiguous images over a period of four or more hours starting at a time that ensured that we would capture the entire transit from beginning to end. Nathan needed to find transit candidates from the Kepler Objects of Interest (KOI) database that would be relatively short (less than 6 hours) and start early enough in the observing run to ensure we could image the entire transit in a single observing run. In addition, he needed to find a transit candidate with a percentage of dimming that would be great enough to ensure the signal to noise ratio (SNR) of the data were high enough to get precise measurements in the required milli-magnitude range. Nathan used the NASA Exoplanet Archive of the KOI candidates to determine which exoplanet candidates met all these requirements.

Starting in September Nathan and I worked together to run some tests on potential candidates to check what exposure times were needed to get an appropriate SNR of 15th magnitude transits with projected dimming of around 5 percent. We determined that 60-second exposures on the SSO 0.6-meter telescope in California would work. Because the project would require using a telescope uninterrupted for several hours and require special attention this was the only telescope I wanted to use for this special project. Nathan and his university paid $400 for credits to do this project, which equates to 4 hours of exposure time on the SSO telescope. In the end it required much more time than this to accomplish and complete Nathan’s project goal. I worked with Nathan to set up several nights of observing runs. A couple of times we were all set to do a run on a good candidate only to get clouded out and have to find another candidate and date to try. In early November everything worked out fine and Nathan got good data that he analyzed and found a transit that matched the projections and thus confirmed his candidate was a real extrasolar planet. This was a very interesting and rewarding project for me to help work on. I gladly donated several nights of observations to help Nathan accomplish his project goals. It was a pretty special and fun project to work on.

Nathan’s blog about his project follows. Be sure to click on the link to his project presentation.

Congratulation Nathan!

  • Rich Williams

Confirming a Kepler Object of Interest (KOI) Exoplanet Using the Sierra Stars Observatory Network

by Nathan Kirse

The video at this link is my talk at the UNC Asheville Undergraduate Fall Research Symposium about my research on KOIs (Kepler Objects of Interest). I am a Junior at the University of North Carolina at Asheville. I am majoring in Physics, and minoring in Astronomy, Computer Science, and Math. This research wouldn’t have been possible if it wasn’t for Rich William’s generosity and patience with me.

My motivation for this research came from when I was able to detect the known “Hot Jupiter” exoplanet WASP-33b via transit method using the school’s 14 inch telescope. This was a project I chose to do in my Observational Astronomy class. Beforehand, there was a lot of doubt on whether or not this was even feasible with the kind of telescope, conditions, and CCD camera we had. So detecting WASP-33b gave me that much more confidence to go try and up the difficulty of this exoplanet-hunting. In fact, why not go for Earth-like planets? I was determined yet utterly naive when taking on this task.

What you see in this video is the story of my quest to detect a KOI, which is an unconfirmed exoplanet, using the Sierra Stars Observatory. I started out with a very small, Earth-like KOI. But it eventually became apparent that this was out of reach for SSO, in other words, the camera was not sensitive enough to detect such a small planet. The next trials involved me testing out larger and larger KOIs.

It was a very big learning experience but eventually I was able to detect the transit of the unconfirmed exoplanet KOI-1654.01. This Saturn-sized planet was my saving grace and gave me something to talk about at the Research Symposium other than, “Unfortunately, no transit was detected.”

Again, I would like to thank Rich Williams for his generosity, it is greatly appreciated. I look forward to working with Rich in the future for any projects I may have. I would also like to give a big thanks to Jason Kendall for connecting me with Rich and all the help he gave, and Dr. Brian Dennison for advising me through this project.

I hope to publish my results in the coming month.


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