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Title: Detection of stars within ∼0.8 in of Kepler objects of interest

We present an algorithm to search for the faint spectrum of a second star mixed with the spectrum of a brighter star in high resolution spectra. We model optical stellar spectra as the sum of two input spectra drawn from a vast library of stars throughout the H-R diagram. From typical spectra having a resolution of R = 60,000, we are able to detect companions as faint as 1% relative to the primary star in approximately the V and R bandpasses of photometry. We are also able to find evidence for triple and quadruple systems, given that any additional companions are sufficiently bright. The precise threshold percentage depends on the signal-to-noise of the spectrum and the properties of the two stars. For cases of non-detection, we place a limit on the brightness of any potential companions. This algorithm is useful for detecting faint orbiting companions and background stars that are angularly close to a foreground target star. The size of the entrance slit to the spectrometer, 0.87 × 3 arcsec (typically), sets the angular domain within which the second star can be detected. We analyzed Keck-HIRES spectra of 1160 California Kepler Survey objects of interest (KOI) searching for the secondarymore » spectra, with the two goals of alerting the community to two possible host stars of the transiting planet and to dilution of the light curve. We report 63 California KOI showing spectroscopic evidence of a secondary star.« less
Authors:
; ;  [1] ;  [2]
  1. University of California, Berkeley, CA 94720 (United States)
  2. Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States)
Publication Date:
OSTI Identifier:
22342095
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (New York, N.Y. Online); Journal Volume: 149; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALGORITHMS; APPROXIMATIONS; BRIGHTNESS; DETECTION; DILUTION; HERTZSPRUNG-RUSSELL DIAGRAM; NOISE; OPTICAL MODELS; PHOTOMETRY; PLANETS; RADIAL VELOCITY; RESOLUTION; SPECTRA; SPECTROMETERS; STARS; VISIBLE RADIATION