Las Campanas Swope Raw Data Collection Overview Data Abstract ============= We obtained images of the (65803) Didymos system and supporting calibration images with the Swope 4K CCD on the Swope 1m Telescope at the Las Campanas Observatory (LCO). These images were taken in order to determine the orbit period of Dimorphos, the satellite of Didymos. This collection consists of the Las Campanas Swope raw images, which include Didymos images and flat field images. Data Set Overview ================= Swope 4K CCD is the visible-wavelength, direct-imaging CCD for the Swope 1m Telescope at Las Campanas Observatory. The camera images a 29.7 x 29.8 arc minute field of view at 0.435"/pixel spatial resolution for unbinned 15 micron pixels. The detector is normally read out in a quad amplifier mode writing to four separate FITS files. Readout time is 37s for the unbinned 4 amplifier mode. Facility filters include Harris BVRI and Sloan griz, with the Sloan r’ adopted for this observing campaign. FITS images obtained with the Swope 4K CCD are written as individual frames for each of the 4 detector amplifiers that are read out. Raw image data include Didymos images and flat fields of the twilight sky, with an overscan region on images used for bias-level subtraction. Dark current is typically very low when imaging with the 4K CCD (especially considering the short exposures adopted for this campaign) so dark frames are not used. Sidereal tracking was used and Didymos was allowed to move across the field. Naming Convention ================= Raw images consist of a single fits file containing the raw image and an associated XML file. They are named according to the following convention. ccd_a_. where: ccd is the camera reference, referring to the Swope 4K CCD is a four-digit image counter for observing session starting at 0001, reset for each night of observation a is the readout amplifier number (1-4) is the UTC year, month, day of observation is the file extension. “.fits” for FITS file format, ".xml" for the PDS4 XML label Ex. ccd1001_a1_220822.fits is a raw Swope image corresponding to readout amplifier 1 from the night of 2022-08-22. It is in the 1001st image set generated on that UT date.