A Catalog of Kepler Habitable Zone Exoplanet Candidates

Abstract

The NASA Kepler mission has discovered thousands of new planetary candidates, many of which have been confirmed through follow-up observations. A primary goal of the mission is to determine the occurrance rate of terrestrial-size planets within the Habitable Zone (HZ) of their host stars. Here we provide a list of HZ exoplanet candidates from the Kepler Data Release 24 Q1-Q17 data vetting process. This work was undertaken as part of the Kepler Habitable Zone Working Group. We use a variety of criteria regarding HZ boundaries and planetary sizes to produce complete lists of HZ candidates, including a catalog of 104 candidates within the optimistic HZ and 20 candidates with radii less than two Earth radii within the conservative HZ. We cross-match our HZ candidates with the Data Release 25 stellar properties and confirmed planet properties to provide robust stellar parameters and candidate dispositions. We also include false positive probabilities recently calculated by Morton et al. (2016) for each of the candidates within our catalogs to aid in their validation. Finally, we performed dynamical analysis simulations for multi-planet systems that contain candidates with radii less than two Earth radii as a step toward validation of those systems.

Habitable Moist Atmospheres on Terrestrial Planets near the Inner Edge of the Habitable Zone around M Dwarfs

“…Discoveries of terrestrial planets in the habitable zone (HZ) by both the Kepler mission and ground-based surveys (Kane et al 2016;Anglada-Escudé et al 2016;Gillon et al 2017) have shown that potentially habitable planets are common in our galaxy (Petigura et al 2013;Foreman-Mackey et a. 2014;Silburt et al 2015;Dressing & Charbonneau 2015).…”

Validation of Small Kepler Transiting Planet Candidates in or near the Habitable Zone

“…The source of our target list is an early version of the catalog of small HZ candidates published by Kane et al (2016), which in turn is the product of the efforts by the Kepler HZ Working Group to evaluate the full set of candidates observed during the mission's quarters 1 through 17 (Q1-Q17). This catalog describes the various definitions used by different authors for the HZ and chose to consider both an "optimistic" (larger) HZ and a "conservative" (smaller) HZ, based on the assumptions of Kopparapu et al (2014) informed by estimates of how long Venus and Mars may have been able to retain liquid water on their surfaces.…”

“…A number of the candidates presented by Kane et al (2016) have been validated by others and have subsequently received official Kepler planet designations. However, in most cases, those validation studies have only been concerned with demonstrating the presence of a planet associated with the target but not necessarily orbiting it.…”

“…KOIs with long orbital periods (P) are even more challenging as the radial-velocity amplitudes fall off as -P 1 3 , resulting in Doppler signals that are often of the order of 1 m s −1 or less, which is at the limit of the detection capabilities of present instrumentation and techniques. Kane et al (2016) recently published a catalog of transiting HZ candidates from Kepler based on the best available set of planetary and stellar parameters available to them. Many of these candidates are nominally smaller than 2 R ⊕ and have relatively long orbital periods up to several hundred days.…”

Probing the Deep End of the Milky Way with New Oscillating Kepler Giants

“…[e.g. [3][4][5] the excellent quality of the photometric data has enabled us to make tremendous progress on the understanding of stellar evolution and dynamics [6][7][8][9][10][11][12][13]. In particular, the mission showed the power of asteroseismology to better constrain the fundamental properties of planet host stars (such as radius and age) needed to characterize planetary systems but also to probe the structure and rotation in deeper layers of stars.…”