Spitzer IRAC Sparsely Sampled Phase Curve of the Exoplanet WASP-14b

TL;DR

This paper introduces a novel sparse sampling technique for exoplanet phase curves using Spitzer IRAC, demonstrating its efficiency and validating it with observations of WASP-14b, a hot Jupiter, to recover key planetary parameters.

Contribution

The study presents a new sparse sampling method for phase curves that is more efficient and easier to schedule than traditional full observations, validated through a pilot study of WASP-14b.

Findings

Successfully recovered transit and eclipse depths.

Placed limits on phase variation of parameters.

No evidence of eclipse depth variation over 3.5 years.

Abstract

Motivated by a high Spitzer IRAC oversubscription rate, we present a new technique of randomly and sparsely sampling phase curves of hot Jupiters. Snapshot phase curves are enabled by technical advances in precision pointing as well as careful characterization of a portion of the central pixel on the array. This method allows for observations which are a factor of roughly two more efficient than full phase curve observations, and are furthermore easier to insert into the Spitzer observing schedule. We present our pilot study from this program using the exoplanet WASP-14b. Data of this system were taken both as a sparsely sampled phase curve as well as a staring mode phase curve. Both datasets as well as snapshot style observations of a calibration star are used to validate this technique. By fitting our WASP-14b phase snapshot dataset, we successfully recover physical parameters for the transit and eclipse depths as well as amplitude and maximum and minimum of the phase curve shape of this slightly eccentric hot Jupiter. We place a limit on the potential phase to phase variation of these parameters since our data are taken over many phases over the course of a year. We see no evidence for eclipse depth variations compared to other published WASP-14b eclipse depths over a 3.5 year baseline.