Week 30 of the Early Operations system optimization period
Colder temperatures and clouds are becoming more frequent as winter approaches. The Simonyi Survey Telescope was closed on 15 May and 20 May due to clouds, and the team turned to in-dome calibrations, taking filter scans using the collimated beam projector (CBP) as well as monochromatic flats.
Nearly all on-sky observations during the week were part of the on-going pre-LSST survey. Per-night median PSF FWHM ranged from 0.8 to 1.2 arcseconds, correlated with estimates of atmosphere seeing. Per-night median estimated instrument contribution to the delivered image quality ranged from 0.4 to 0.5 arcseconds. Per-night median ellipticity ranged from 0.07 to 0.08. The overall trending of delivered image quality has been similar to recent weeks since mid-April.
The team deployed griz templates for Alert Production from the wide-area component of the commissioning-era Science Validation (SV) surveys, increasing the currently deployed template area coverage by approximately a factor of 10. More information, including visualizations for the currently deployed template coverage, is available here. General documentation on Prompt Products is available at https://prompt-products.lsst.io.
The team deployed an update for the telescope pointing to account for closed loop corrections of the Active Optics System (AOS).
The currently installed filter set is ugriz. A filter swap to remove u and install the y filter is planned for 26 May such that the new filter set would be grizy.