The Joint ALMA Observatory (JAO) is now accepting observing proposals for Cycle 8 2021 that request to use the Atacama Compact Array (ACA) in stand-alone mode. Instructions on how to submit proposals can be found on the Cycle 8 2021 Supplemental Call web page.

Users of any nationality or affiliation are invited to submit proposals before the deadline of 15:00 UT on Wednesday 6 October 2021.

PI science observations have been continuing with the 12-m and Morita Arrays. As reported in the previous status update, there was a delay in the antenna configuration schedule due to the bad weather since May, in addition to the impact from the COVID-19 pandemic. There were no further delays since then, and the relocation to the hybrid C43-9/10 configuration was completed on 1 September, 2021.

The Cycle 8 Supplemental Call for Proposals is anticipated to open at 15:00 UT on September 8 with a proposal deadline of 15:00 UT on October 6. ALMA expects to allocate a minimum of 1500 h of observing time on the ACA in the Supplemental Call. Proposals are encouraged between a LST range of 20 to 10 h. Preliminary information is currently available. Complete details of the Supplemental Call will be posted on the ALMA Science Portal on September 8.

A detailed report on the outcome of the ALMA Cycle 8 2021 Proposal Review Process is now available. The report details the proposal review process, proposal statistics and regional distributions, as well as the proposal distribution across science categories and receiver bands. The highest priority Cycle 8 2021 projects are listed at this link.

ALMA has begun work on correcting some Cycle 7 interferometric datasets for a visibility amplitude calibration error that affects fields containing strong astronomical emission – details were described in this previous announcement. For all affected datasets with a >10% flux scale offset that have yet to be delivered, including those that will be observed in the remainder of Cycle 7 and in Cycle 8 2021, ALMA will apply a renormalization correction during data processing to correctly scale the amplitude calibration before being sent to PIs.

The ESO internal ALMA development study "ESO-ALLEGRO Phase RMS database" officially started in July 2021. Since site testing studies conducted over two-decades ago there have been no statistical studies, nor material presented to explore the atmospheric variations (phase RMS) of the thousands of accrued ALMA observations. The Phase RMS study will remedy this.

Cycle 7 PI science observations have been continuing, although with some significant interruption due to snowstorms at the end of May and in mid-June. Combined with pandemic conditions affecting maximum staffing levels at the site, this led to a delay in reaching the 12-m Array C43-7 configuration (completed on 12 July). Unfortunately, the delay has an impact on the configuration schedule for the remainder of Cycle 7.

A visibility amplitude calibration error that affects fields containing strong line emission has been discovered in ALMA interferometer observations up to and including Cycle 7.