STELLAR AND PLANETARY PROPERTIES OF K2 CAMPAIGN 1 CANDIDATES AND VALIDATION OF 17 PLANETS, INCLUDING A PLANET RECEIVING EARTH-LIKE INSOLATION

By B. Montet, Timothy Morton, Daniel Foreman-Mackey, J. Johnson, David W. Hogg, B. Bowler, D. Latham, A. Bieryla, A. Mann. 2015

116 citations recorded by the source corpus.

The extended Kepler mission, K2, is now providing photometry of new fields every three months in a search for transiting planets. In a recent study, Foreman-Mackey and collaborators presented a list of 36 planet candidates orbiting 31 stars in K2 Campaign 1. In this contribution, we present stellar and planetary properties for all systems. We combine ground-based seeing-limited survey data and adaptive optics imaging with an automated transit analysis scheme to validate 21 candidates as planets, 17 for the first time, and identify 6 candidates as likely false positives. Of particular interest is K2-18 (EPIC 201912552), a bright (K = 8.9) M2.8 dwarf hosting a 2.23 ± 0.25 R ⨁ ?> planet with T eq = 272 ± 15 ?> K and an orbital period of 33 days. We also present two new open-source software packages which enable this analysis. The first, isochrones, is a flexible tool for fitting theoretical stellar models to observational data to determine stellar properties using a nested sampling scheme to capture the multimodal nature of the posterior distributions of the physical parameters of stars that may plausibly be evolved. The second is vespa, a new general-purpose procedure to calculate false positive probabilities and statistically validate transiting exoplanets.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics, AI for Physical Sciences

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Citations in the corpus

Toward Causal Representation Learning (2021, background): “The application of [218] leads to the discovery of 36 planet candidates [71], of which 21 were subsequently validated as bona fide exoplanets [172].”
Towards Causal Representation Learning (2021, neutral): “subsequently validated as bona fide exoplanets [172].”
Causality for Machine Learning (2019, methodology): “et transits and an efﬁcient way to search light curves, leading to the discovery of 36 planet candidates (Foreman-Mackey et al., 2015), of which 21 were subsequently validated as bona ﬁde exoplanets (Montet et al., 2015). Four years later, astronomers found traces of water in the atmosphere of the e”
197 CANDIDATES AND 104 VALIDATED PLANETS IN K2's FIRST FIVE FIELDS (2016, background): “…of planet candidates (Foreman-Mackey et al. 2015; Adams et al. 2016; Vanderburg et al. 2016), and a growing sample of validated and/or confirmed planets (e.g., Vanderburg & Johnson 2014; Crossfield et al. 2015; Huang et al. 2015; Montet et al. 2015; Sanchis-Ojeda et al. 2015; Sinukoff et al. 2016).”
The CARMENES Search for Exoplanets around M Dwarfs: A Low-mass Planet in the Temperate Zone of the Nearby K2-18 (2018, methodology): “Second, the planet transits (Montet et al. 2015; Benneke et al. 2017) and, therefore, we expect another signal in the data close to the orbital period of the planet.”
WASP-47: A HOT JUPITER SYSTEM WITH TWO ADDITIONAL PLANETS DISCOVERED BY K2 (2015, background): “Following Montet et al. (2015), we define a conservative radius inside of which background sources could cause the transits.”
They are small worlds after all: revised properties of Kepler M dwarf stars and their planets (2015, background): “Several candidate planets orbiting M dwarfs have already been reported (Crossfield et al. 2015; Montet et al. 2015; Mann et al. 2015b).”
Characterization of the K2-18 multi-planetary system with HARPS: A habitable zone super-Earth and discovery of a second, warm super-Earth on a non-coplanar orbit (2017, methodology): “Models shown include a suite of rp,c values including its upper limit derived from MCMC (0.52 R⊕), 0.75 R⊕, 1 R⊕, and the radius of K2-18b (2.38 R⊕) which is detected at the 10σ level in the K2 photometry (Montet et al. 2015).”
FALSE POSITIVE PROBABILITIES FOR ALL KEPLER OBJECTS OF INTEREST: 1284 NEWLY VALIDATED PLANETS AND 428 LIKELY FALSE POSITIVES (2016, methodology): “E P] 1 0 M ay 2 01 6 applied to a number of candidates found by the K2 mission (Montet et al. 2015; Becker et al. 2015).”
SPITZER OBSERVATIONS CONFIRM AND RESCUE THE HABITABLE-ZONE SUPER-EARTH K2-18b FOR FUTURE CHARACTERIZATION (2016, methodology): “The transit of K2-18b appears 7σ (1.85 hours) before the predicted transit time from Montet et al. 2015 (vertical black line).”
EVEREST: PIXEL LEVEL DECORRELATION OF K2 LIGHT CURVES (2016, methodology): “We note that our method is similar to that of Foreman-Mackey et al. (2015) and Montet et al. (2015), who use the principal components of the variability among the full set of K2 campaign 1 light curves as “eigen light curve” regressors.”
THE K2 ECLIPTIC PLANE INPUT CATALOG (EPIC) AND STELLAR CLASSIFICATIONS OF 138,600 TARGETS IN CAMPAIGNS 1–8 (2015, result): “Conversely, K2-6 (EPIC201384232) was classified as a sun-like dwarf by Montet et al. (2015) (Teff = 5850 +79 −98K, R = 0.96 +0.14 −0.09R⊙), consistent with high-resolution spectroscopy by Vanderburg et al. (2016), while our results (based on a spectroscopic classification from RAVE) favor a…”
PLANETARY CANDIDATES FROM THE FIRST YEAR OF THE K2 MISSION (2015, methodology): “…then, a variety of new K2 data analysis techniques and planet detections have been presented (Aigrain et al. 2015; Armstrong et al. 2015a,b; LaCourse et al. 2015; Foreman-Mackey et al. 2015; Montet et al. 2015; Sanchis-Ojeda et al. 2015; Huang et al. 2015a,b; Angus et al. 2015; Lund et al. 2015).”