The Cycle 13 Call for Proposals will open on March 19, 2026, inviting astronomers from around the world to submit observations proposals for ALMA’s next scientific cycle.

Observations will begin in October 2026 and will run for 12 months. A total of 4,300 hours of observation time will be offered using the 12-meter Array and the Morita Array (Atacama Compact Array – ACA). This time will enable studies of a wide range of astrophysical topics, from the formation of stars and planets to the evolution of galaxies over cosmic time.

Proposal preparation: new web tool

For this cycle, proposals will be prepared using a web version of the ALMA Observing Tool, replacing the desktop application previously used.

The new tool preserves the familiar workflow for proposals preparation while allowing users to create and manage their projects directly from a web browser.

Astronomers planning to submit proposals are encouraged to begin preparing their observing programs in advance.Documentation will be available on the ALMA Science Portal when the Call for Proposals is released on March 19.

Expected capabilities for Cycle 13

Observations during this cycle will use the standard 12-meter Array configurations from C-1 to C-10, enabling baselines ranging from 0.16 km to 16 km.

Cycle 13 will also mark the introduction of Band 2 (67–116 GHz) in the 12-meter array. This new capability expands ALMA’s frequency coverage and enables the observation of key molecular transitions that trace cold gas – the raw material for star formation – in the interstellar medium of nearby and distant galaxies.