Comparing Period Fitting Methods to Exoplanets in APOGEE
Grade Level at Time of Presentation
Junior
Major
Mathematics
Minor
Astronomy
Institution
Northern Kentucky University
KY House District #
68
KY Senate District #
24
Faculty Advisor/ Mentor
Nathan De Lee, PhD.
Department
Physics, Geology, and Engineering Technology
Abstract
The APO Galactic Evolution Experiment (APOGEE-1) survey took high-resolution H-Band, infrared, spectroscopy of 146,000 stars (as of SDSS-IV Data Release 12). Of these, 14,840 stars had at least 8 radial velocity (RV) epochs with baselines up to 3 years (~1000 days) making them suitable for orbit fitting. Of these, 14,840 stars had at least 8 radial velocity (RV) epochs with baselines up to 3 years, making them suitable for orbit fitting. In previous work, 382 of the 14,840 orbits were selected for inclusion in a gold sample of stars with well-characterized orbits. In our project, we have used both Lomb-Scargle and Fast chi-squared type periodograms to fit periods to APOGEE style simulated RV curves. Using these periods, we fitted a Keplerian orbit to each star and assigned it a semi-amplitude, eccentricity, argument of periastron, and epoch of periastron. We then compared these orbital elements to the known values for the simulated data to determine our detection efficiency. We then used these results to guide our interpretation of current fits to the gold sample.
Comparing Period Fitting Methods to Exoplanets in APOGEE
The APO Galactic Evolution Experiment (APOGEE-1) survey took high-resolution H-Band, infrared, spectroscopy of 146,000 stars (as of SDSS-IV Data Release 12). Of these, 14,840 stars had at least 8 radial velocity (RV) epochs with baselines up to 3 years (~1000 days) making them suitable for orbit fitting. Of these, 14,840 stars had at least 8 radial velocity (RV) epochs with baselines up to 3 years, making them suitable for orbit fitting. In previous work, 382 of the 14,840 orbits were selected for inclusion in a gold sample of stars with well-characterized orbits. In our project, we have used both Lomb-Scargle and Fast chi-squared type periodograms to fit periods to APOGEE style simulated RV curves. Using these periods, we fitted a Keplerian orbit to each star and assigned it a semi-amplitude, eccentricity, argument of periastron, and epoch of periastron. We then compared these orbital elements to the known values for the simulated data to determine our detection efficiency. We then used these results to guide our interpretation of current fits to the gold sample.