The RKSTAR Concert: A RECONS Survey of the 5000 Nearest K Dwarfs

The RKSTAR (RECONS K Stars) Project targets the 5000 nearest K dwarfs, all within 50 parsecs of the Sun. This is a critical sample for astrophysical studies and exoplanet searches, addressing science questions from the star formation history in the Milky Way to potential locations for life-bearing worlds. To paint a complete portrait of the sample, RECONS (REsearch Consortium On Nearby Stars, www.recons.org) is conducting four systematic surveys of these K dwarfs.

• Characterization Survey ⏤ utilizes the CHIRON high-resolution spectrograph on the SMARTS 1.5m at CTIO. The spectra provide accurate temperatures, metallicities, and measurements of activity indices that are used to estimate ages.

• Wide Field Survey ⏤ targets stellar companions at separations larger than ~1 arcsecond, revealed using Gaia results and cataloged companions from the Washington Double Stars Catalog.  Nearly 500 stellar companions, ~80 of which are new discoveries, have been identified out to ~4000AU.

• Speckle Survey ⏤ reveals stellar companions from 0.5-100 AU using speckle cameras on 4 to 8m class telescopes. More than 160 stellar companions, ~90 of which are new discoveries, have been found so far, and most orbit within 15 AU of the K dwarfs.

• Radial Velocity Survey ⏤ utilizes CHIRON on the SMARTS 1.5m to reveal stars, brown dwarfs, and jovian exoplanets orbiting the K dwarfs within 3 AU. Dozens of stellar companions and several new planets have already been discovered.

  The four surveys will provide an unprecedented dataset describing the characteristics and

  companions to the stars that make up 12% of all stars in the solar neighborhood.