A NEARBY M STAR WITH THREE TRANSITING SUPER-EARTHS DISCOVERED BY K2

By I. Crossfield, E. Petigura, J. Schlieder, Andrew W. Howard, B. Fulton, K. Aller, D. Ciardi, S. Lépine, T. Barclay, I. Pater and 17 more. 2015

126 citations recorded by the source corpus.

Small, cool planets represent the typical end-products of planetary formation. Studying the architectures of these systems, measuring planet masses and radii, and observing these planets’ atmospheres during transit directly informs theories of planet assembly, migration, and evolution. Here we report the discovery of three small planets orbiting a bright (Ks = 8.6 mag) M0 dwarf using data collected as part of K2, the new ecliptic survey using the re-purposed Kepler spacecraft. Stellar spectroscopy and K2 photometry indicate that the system hosts three transiting planets with radii 1.5–2.1 R ⨁ ?> , straddling the transition region between rocky and increasingly volatile-dominated compositions. With orbital periods of 10–45 days the planets receive just 1.5–10× the flux incident on Earth, making these some of the coolest small planets known orbiting a nearby star; planet d is located near the inner edge of the system’s habitable zone. The bright, low-mass star makes this system an excellent laboratory to determine the planets’ masses via Doppler spectroscopy and to constrain their atmospheric compositions via transit spectroscopy. This discovery demonstrates the ability of K2 and future space-based transit searches to find many fascinating objects of interest.

Subfields: Astronomy and Astrophysics

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Citations in the corpus

STELLAR AND PLANETARY PROPERTIES OF K2 CAMPAIGN 1 CANDIDATES AND VALIDATION OF 17 PLANETS, INCLUDING A PLANET RECEIVING EARTH-LIKE INSOLATION (2015, background): “Of our planet candidate hosts, only K2-3 (originally discovered by Crossfield et al. 2015) is brighter in K-band.”
A SYSTEMATIC SEARCH FOR TRANSITING PLANETS IN THE K2 DATA (2015, methodology): “Following Vanderburg & Johnson (2014), we choose the aperture size with the minimum CDPP (Christiansen et al. 2012) with a 6 hour window.3 All previous methods for analyzing K2 data involve some sort of “correction” or “de- trending” step based on measurements of the pointing of the spacecraft (Vand”
One of the closest exoplanet pairs to the 3:2 mean motion resonance: K2-19b and c (2015, background): “A number of interesting systems have already come to light (Crossfield et al. 2015; Vanderburg et al. 2014; Foreman-Mackey et al. 2015).”
SPITZER OBSERVATIONS CONFIRM AND RESCUE THE HABITABLE-ZONE SUPER-EARTH K2-18b FOR FUTURE CHARACTERIZATION (2016, methodology): “Following the procedure described in Crossfield et al. (2015), Petigura et al. (2015), and Schlieder et al. (2016), we obtain stellar properties that are consistent with the stellar properties reported by Montet et al. (2015) (Table 2).”
THE K2 ECLIPTIC PLANE INPUT CATALOG (EPIC) AND STELLAR CLASSIFICATIONS OF 138,600 TARGETS IN CAMPAIGNS 1–8 (2015, background): “…have a bimodal distribution as a result of programs targeting bright FGK dwarfs and red giants for transiting planet searches and galactic archeology (e.g. Vanderburg et al. 2015; Stello et al. 2015), while M dwarf exoplanet surveys (e.g. Crossfield et al. 2015) typically propose fainter targets.”
The CARMENES Search for Exoplanets around M Dwarfs: A Low-mass Planet in the Temperate Zone of the Nearby K2-18 (2018, background): “…discoveries of Earth-like low-mass planets orbiting in the habitable zones of M stars have demonstrated the importance of these targets (e.g., Crossfield et al. 2015; Gillon et al. 2017; Dittmann et al. 2017; Bonfils et al. 2017), with perhaps the most exciting discovery being the detection…”
PLANETARY CANDIDATES FROM THE FIRST YEAR OF THE K2 MISSION (2015, background): “Soon thereafter, K2 began successfully detecting new exoplanets (Vanderburg et al. 2015b; Crossfield et al. 2015).”
EVEREST: PIXEL LEVEL DECORRELATION OF K2 LIGHT CURVES (2016, methodology): “Though other pipelines exist (e.g., Lund et al. 2015; Huang et al. 2015; Crossfield et al. 2015), here we focus on those that are also available for download at the MAST HLSP K2 archive.7 For each of the pipelines, we download all available de-trended light curves and compute the CDPP as 7…”
K2 Variable Catalogue: Variable Stars and Eclipsing Binaries in K2 Campaigns 1 and 0 (2015, background): “Already the K2 mission has been used to identify new candidate eclipsing binaries (Conroy et al. 2014), and produced new interesting planetary systems (Crossfield et al. 2015; Vanderburg et al. 2015).”
DISCOVERY AND VALIDATION OF Kepler-452b: A 1.6 R⨁ SUPER EARTH EXOPLANET IN THE HABITABLE ZONE OF A G2 STAR (2015, background): “The repurposed Kepler Mission, dubbed K2, has also added a small planet on the inside edge of its habitable zone: K2-3d (aka EPIC 201367065d; Crossfield et al. 2015).”
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).”
The Habitability of Planets Orbiting M-dwarf Stars (2016, background): “In the last few years, many systems of multiple planets orbiting M-dwarf stars have been discovered (AngladaEscudé et al., 2013; Quintana et al., 2014; Rowe et al., 2014; Torres et al., 2015; Crossfield et al., 2015; Barclay et al., 2015).”
197 CANDIDATES AND 104 VALIDATED PLANETS IN K2's FIRST FIVE FIELDS (2016, methodology): “…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).”