THE KEPLER FOLLOW-UP OBSERVATION PROGRAM. I. A CATALOG OF COMPANIONS TO KEPLER STARS FROM HIGH-RESOLUTION IMAGING

By E. Furlan, D. Ciardi, M. Everett, M. Saylors, J. Teske, Elliott Horch, S. B. Howell, G. V. Belle, L. Hirsch, T. Gautier and 9 more. 2016

187 citations recorded by the source corpus.

We present results from high-resolution, optical to near-IR imaging of host stars of Kepler Objects of Interest (KOIs), identified in the original Kepler field. Part of the data were obtained under the Kepler imaging follow-up observation program over six years (2009–2015). Almost 90% of stars that are hosts to planet candidates or confirmed planets were observed. We combine measurements of companions to KOI host stars from different bands to create a comprehensive catalog of projected separations, position angles, and magnitude differences for all detected companion stars (some of which may not be bound). Our compilation includes 2297 companions around 1903 primary stars. From high-resolution imaging, we find that ∼10% (∼30%) of the observed stars have at least one companion detected within 1″ (4″). The true fraction of systems with close (≲4″) companions is larger than the observed one due to the limited sensitivities of the imaging data. We derive correction factors for planet radii caused by the dilution of the transit depth: assuming that planets orbit the primary stars or the brightest companion stars, the average correction factors are 1.06 and 3.09, respectively. The true effect of transit dilution lies in between these two cases and varies with each system. Applying these factors to planet radii decreases the number of KOI planets with radii smaller than 2 by ∼2%–23% and thus affects planet occurrence rates. This effect will also be important for the yield of small planets from future transit missions such as TESS.

Subfields: Astronomy and Astrophysics, Spectroscopy

View Paper: https://www.semanticscholar.org/paper/1347f4ad16eedf11b38284313b3d496ab4749b93

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. J. Owen
2. Timothy Morton
3. E. Petigura
4. B. Fulton
5. Andrew W. Howard
6. J. Johnson
7. G. Marcy
8. Andrew Vanderburg

In Spectroscopy

1. J. Owen
2. A. Cumming
3. G. Marcy
4. I. Snellen

Citations in the corpus

• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets (2017, methodology): “Furlan et al. (2017) compiled a catalog of KOI host stars that were observed using a collection of highresolution imaging facilities (Lillo-Box et al. 2012, 2014; Horch et al. 2012, 2014; Everett et al. 2015; Gilliland et al. 2015; Cartier et al. 2015; Wang et al. 2015a,b; Adams et al. 2012, 2013;…”
• The California-Kepler Survey. VII. Precise Planet Radii Leveraging Gaia DR2 Reveal the Stellar Mass Dependence of the Planet Radius Gap (2018, methodology): “When a nearby star is detected, Furlan et al. (2017) computed a radius correction factor (RCF), which accounts for dilution assuming the planet transits the brightest star.”
• The California-Kepler Survey. V. Peas in a Pod: Planets in a Kepler Multi-planet System Are Similar in Size and Regularly Spaced (2017, methodology): “We then discarded stars that were diluted by at least 5% by a second star in the Kepler aperture (as determined in the stellar companion catalog of Furlan et al. 2017), removing 30 stars hosting 69 planet candidates.”
• Identifying Exoplanets with Deep Learning: A Five-planet Resonant Chain around Kepler-80 and an Eighth Planet around Kepler-90 (2017, background): “…companion to Kepler-534, however, is apparently close enough to the target star that it a) contributed light to the Keck HIRES spectrograph’s slit, and b) was not detected with Robo-AO and Palomar Observatory adaptive optics imaging (Ziegler et al. 2017; Wang et al. 2015a; Furlan et al. 2017).”
• An asteroseismic view of the radius valley: stripped cores, not born rocky (2017, background): “The stars are cross-checked for contamination from nearby stars from high-resolution imaging (e.g. Furlan et al. 2017).”
• The California-Kepler Survey. I. High-resolution Spectroscopy of 1305 Stars Hosting Kepler Transiting Planets (2017, background): “…many facilities operated by dozens of astronomers.16 These observations included direct imaging (Adams et al. 2012, 2013; Baranec et al. 2016; Ziegler et al. 2017; Furlan et al. 2017) as well as high-resolution spectroscopy (Gautier et al. 2012; Everett et al. 2013; Buchhave et al. 2012, 2014).”
• The California-Kepler Survey. IV. Metal-rich Stars Host a Greater Diversity of Planets (2017, background): “Furlan et al. (2017) compiled high-resolution imaging observations performed by several groups.2 When a nearby star is detected, Furlan et al. (2017) computed a radius correction factor (RCF) which accounts for dilution assuming the planet transits the brightest star.”