Multiband Photometry Simulations to Predict MuSCAT and MuSCAT2 Capabilities to Distinguish TESS-discovered Exoplanets from False Positives
Abstract
The Transiting Exoplanet Survey Satellite (TESS) is currently conducting its 2-year science mission searching most of the sky for transiting exoplanets. Barclay et al. (2018) predict that TESS will discover thousands of new candidate exoplanets, but these exoplanets must be distinguished from astrophysical false positives using other instruments or techniques. The Japanese-developed 3-band Multi-color Simultaneous Camera for Studying Atmospheres of Transiting Planets (MuSCAT), as well as the 4-band MuSCAT2, can be used to validate TESS discoveries. Transits of exoplanets are achromatic when observed in multiple bandpasses, while transit depths for false positives often vary with wavelength. Our goal is to simulate MuSCAT/MuSCAT2 follow-up observations to reveal which planet candidates can be efficiently validated using MuSCAT/MuSCAT2, and which must be validated using other techniques. This will allow the TESS Follow-Up Observing Program (TFOP) working group to better prioritize and optimize validations of TESS detections. We provide two software tools to assist TFOP in planning MuSCAT follow-up observations: 1.) A code to produce simulated light curves of exoplanets and false positives observed using MuSCAT/MuSCAT2; 2.) A code that will read a list of parameters for several TESS targets of interest (TOIs), and output the sensitivities in each MuSCAT/MuSCAT2 bandpass for effective planet versus false-positive discrimination. We model observations starting with a model stellar spectrum and ending with detection of electrons on the MuSCAT/MuSCAT2 CCD arrays. We scale the stellar flux to the star’s apparent magnitude, model the effects of refraction and transmission through Earth’s atmosphere, and include noise sources from the target star, comparison stars, sky background, scintillation, and CCD read noise. We model MuSCAT/MuSCAT2 instrument performance as reported by Narita et al. (2015, 2018). We demonstrate our tools by applying them to the Barclay et al. predicted TESS discoveries, as well as the Collins et al. (2018) false positive catalog.
- Publication:
-
American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23314010L