A New Home for an Old Hand: The Differential Speckle Survey Instrument Goes to Apache Point

The Differential Speckle Survey Instrument (DSSI) was built in 2008 and in its first 14 years saw substantial use in diffraction-limited imaging projects at the WIYN Telescope, Gemini-N and Gemini-S, and the Lowell Discovery Telescope. However, the completion and commissioning of the QWSSI speckle camera at Lowell Observatory has recently created the opportunity to move DSSI to the ARC 3.5-m Telescope at Apache Point Observatory (APO) in New Mexico. We report here on the commissioning of DSSI at APO and discuss some of the early science results, which represent the first diffraction-limited images in the visible range ever obtained at the ARC Telescope. Our initial observations appear to be comparable to DSSI's earlier use at WIYN in that we can obtain 0.05-arcsecond resolution at 692 nm for stars as faint as 12th magnitude in five minutes of observing or less, and we can detect companions with magnitude differences of 4 to 5 relative to their primary stars. In the near term, the instrument will be used (1) to supplement observations for the RECONS K Stars project to survey nearby K dwarfs for companions and (2) to obtain follow-up observations of binaries identified by Kepler, TESS, APOGEE, and other sources. It will also provide a testbed for simultaneous visible and infrared speckle imaging and speckle imaging through coherent fiber bundles. The potential advantages of these two innovations include better photometry in the diffraction-limited regime and higher-quality image reconstructions overall. We gratefully acknowledge support from National Science Foundation grants AST-1909560 and AST-1910130, as well as a SEED grant from the Research Corporation for Science Advancement, in the completion of this work.

Conference Name: American Astronomical Society Meeting Abstracts ADS Bibcode: 2023AAS...24130506H