Follow-up observations and confirmation of K2 exoplanet candidates
Bachelor of Arts
Planets, Exoplanets, Astronomy, Astrophysics
We present the results of an 8-month follow-up transit photometry campaign focused on observing exoplanet candidates produced by the K2mission. Observations were conducted at the McConnell rooftop observatory at Smith College in Northampton,MA,with a 16” telescope and CCD. Targets were observed through a clear filter at a 1 minute cadence, usually for the duration of the transit. Our light curves (relative brightness vs time) typically have an RMS of 2 millimagnitudes (mmag) for an 11th-magnitude star. Candidates were selected mainly on the following criteria: a transit depth of over 10 mmag, a host star magnitude between 10-14 mag in the Kepler photometric system,a duration that iso bservable over the span of a night,and a period shorter than 30days. There are currently around 700 unconfirmed exoplanets from K2, an d these criteria shortened that list to around 20 ideal candidates, many of which were flagged by both the Kepler analytics system and by other exoplanet researchers as possible false positives. We observed a total of 6 K2 candidates,one of which was observed twice. 1 candidate showed a clear V-shaped light curve suggesting it is an eclipsing binary rather than an exoplanet; for 2 candidates we were not able to use the light curve to discriminate between exoplanets and eclipsing binaries or other sources; and for 3 candidates we detected no transit, probably due to errors in the period previously reported by others, or else to undetectably shallow transit depths. Our results showcase the capability of small observatories to conduct precise follow-up observations of exoplanet transits and to confirm or reject planets,including eclipsing binary stars.Our program will be especially well-suited to following up candidates from theTransiting Exoplanet Survey Satellite.
2018 Rachel Eileen O'Connor. Access limited to the Smith College community and other researchers while on campus. Smith College community members also may access from off-campus using a Smith College log-in. Other off-campus researchers may request a copy through Interlibrary Loan for personal use.
O'Connor, Rachel Eileen, "Worlds beyond : follow-up observations and confirmation of K2 exoplanet candidates" (2018). Honors Project, Smith College, Northampton, MA.
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