Discovering New Stellar, Brown Dwarf, and Planetary Companions Orbiting 472 of the Nearest K Dwarfs
Abstract
The K-KIDS project is a comprehensive study of the multiplicity of ~5000 K dwarfs within 50 pc. K-KIDS aims to search for stellar, substellar, and planetary companions using three observational techniques to cover separations from 10 000 AU to 0.1 AU. Our search differs from previous efforts because it is systematic — ALL stars are included so that comprehensive demographics can be determined for various types of companions. In this work, we present the first wave of results of our companion search for K dwarfs using the radial velocity technique. Of the 472 K dwarfs within 33 pc and between DEC +30º and -30º, a surprisingly large sample of 300 K dwarfs did not have high precision radial velocity measurements before, and this sample is the focus of our effort to make this portion of the survey volume-complete.Now in the third year of the survey using the CHIRON Spectrograph at the CTIO/SMARTS 1.5m, we have achieved precisions down to 5 m/s for K dwarfs with V magnitudes between 7.0-11.5. Among the 300 stars we have found 88 radial velocity perturbations consistent with companions, of which 44 are stellar nature, 15 are likely brown dwarfs, and 24 are likely planet candidates. Among these 88 perturbations, 66 are first detections. We have solved Keplerian orbits for 17 systems and combined the results from known companions to paint a detailed portrait of K dwarf systems and their orbital architectures. Ultimately, by using a careful defined sample, a multi-technique systematic search, and the combination of previous studies, the K-KIDS project will provide key insights for understanding star and planet formation processes for decades to come.This effort has been supported by the NSF through grant AST-1910130 via observations made possible by the SMARTS Consortium.
- Publication:
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American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23537403P