RV Variability in Kepler


Suvrath Mahadevan
Penn State
suvrath -at- astro.psu.edu

Other contacts

Chad Bender, Rohit Deshpande, Scott Fleming, Robert Marchwinski, David Nidever


Probing Binarity, Elemental Abundances, and False Positives Among the Kepler Planet Hosts

Finding Targets

An object whose APOGEE_TARGET2 value includes one or more of the bitmasks in the following table was targeted for spectroscopy as part of this ancillary target program. See SDSS bitmasks to learn how to use these values to identify objects in this ancillary target program.

Program (bit name) Bit number Target Description
APOGEE_RV_MONITOR_KEPLER 19 Kepler planet host or binary monitored for RV variability


This ancillary project has observed 159 Kepler Objects of Interest (KOI), identified from the Q1-Q16 data, in Kepler module 18 at high cadence (~21 observations) over a period of 8 months to study binarity, abundances, and false positives in the planet host sample. With APOGEE’s RV precision, this project will detect stellar companions and brown dwarfs to Kepler host stars, identify false positives, provide detailed abundances for several elements, and put planet formation in context with binarity. This project also includes 23 M dwarfs and 25 eclipsing binaries. See Fleming et al. (2015) for the first published results.

Target Selection Details

KOI: The KOI selection tag is attached to any object with periodic photometric behavior that could be caused by transiting planets. The NExScI archive curates and manages the list of KOIs, and we used the active list current on August 15, 2013. The KOIs are further split into categories Confirmed, Candidate, Not Dispositioned, and False Positive. Our selection criteria was to select KOI host stars with H < 14 mag (Vega), not listed as False Positive, that lie within the 3 degree SDSS plate field of view.

Eclipsing Binaries: We use selection criteria of H < 13 mag, with orbital period > 5 days, and classified as having a “detached morphology” as listed in the catalogs of Prša et al. (2011) and Slawson et al. (2011). Two eclipsing binaries that also have asteroseismic detections are drawn from Gaulme et al. (2013).

M Dwarfs: A sample of M dwarfs were drawn from the catalog of Dressing & Charbonneau (2013) with Teff < 3500 K and H < 14 mag. This sample represents some of the coolest (and lowest mass) M dwarf stars observed by Kepler, typically of spectral types M3 and later.


Dressing, C. D. & Charbonneau D. 2013, ApJ, 767, 95
Fleming, S. W. et al. 2015, AJ, 149, 143
Gaulme et al. 2013, ApJL, 767L, 82
Prša, A. et al. 2011, AJ, 141, 83
Slawson, R., Prša, A., Welsh, W. F. et al. 2011, AJ, 142, 160
Stello et al. 2013, ApJ, 765L, 41S