Planetary Candidates from K2 Campaign 16

TL;DR

This paper presents a catalog of planet candidates, eclipsing binaries, and variable stars from K2 Campaign 16, including a promising planet candidate around HD 73344, to facilitate rapid follow-up and prepare for TESS data analysis.

Contribution

It provides the first rapid-release catalog of targets from K2 Campaign 16, including system parameters and vetting plots, and demonstrates a methodology for quick candidate identification for future missions.

Findings

30 high-quality planet candidates identified

48 ambiguous events potentially planets or false positives

A promising 2.56 Earth-radius planet candidate orbiting HD 73344

Abstract

Given that Campaign 16 of the K2 mission is one of just two K2 campaigns observed so far in "forward-facing" mode, which enables immediate follow-up observations from the ground, we present a catalog of interesting targets identified through photometry alone. Our catalog includes 30 high-quality planet candidates (showing no signs of being non-planetary in nature), 48 more ambiguous events that may be either planets or false positives, 164 eclipsing binaries, and 231 other regularly periodic variable sources. We have released light curves for all targets in C16, and have also released system parameters and transit vetting plots for all interesting candidates identified in this paper. Of particular interest is a candidate planet orbiting the bright F dwarf HD 73344 (V=6.9, K=5.6) with an orbital period of 15 days. If confirmed, this object would correspond to a $2.56 \pm 0.18 \ R_\oplus$ planet and would likely be a favorable target for radial velocity characterization. This paper is intended as a rapid release of planet candidates, eclipsing binaries and other interesting periodic variables to maximize the scientific yield of this campaign, and as a test run for the upcoming TESS mission, whose frequent data releases call for similarly rapid candidate identification and efficient follow-up.