ALMA Cycle 4

Solar observing was offered for the first time during ALMA Cycle 4. On this page, we provided information regarding the preparation of proposals in 2015.  

Please note that all given information is to the best of our knowledge but without engagement. Please always check the specified documents and links (in particular the Proposer’s Guide). This page will be continuously updated until the proposal deadline.

Call for proposals

The call for proposals has been published on March 22nd, 2015, 15:00UT and can be found here:

ALMA proposals

Proposals have to be prepared using the ALMA Observing Tool (OT), which can be downloaded from the ALMA Science Portal ( Documentation is listed in the Proposer’s Guide (Sect. 5.6.1). The Proposer’s Guide can be downloaded here: (Or click here for a direct link to the PDF document.)

  • Important: Not only the PIs but also all CoIs should be registered on the ALMA Science Portal. Make sure that you and all of your Co-Is register as early as possible. Go to and click on "register" (top right).
  • The proposal title (as to be entered in the OT) may have up to 120 characters.
  • The abstract (as to be entered in the OT) may have up to 1200 characters.

You will also have to prepare a 4-page document for the Science Case (aka scientific justification), which has to be uploaded in the OT as PDF. It is recommended to use 2 pages for the text on the science case. Please use font size 12pt (or bigger). All figures needed for the proposal, including material for technical issues, have to be included in the remaining 2 pages. A latex template for this document is available:

See here for more hints and information regarding the preparation of proposals with the OT and the Science Case document.



Each ALMA Regional Center (ARC) provides services for their user communities including webpages with information and a helpdesk.

Direct link to helpdesk: (Login required. Please register on the ALMA Science Portal!) You can ask for help (by submitting a ticket) and also check the knowledgebase, which contains several very helpful entries.

We provide more hints and information regarding the preparation of proposals here.

Time contingents

The number of successful proposals is adjusted according to the share of the ALMA partners, i.e. 25% for EA and 37.5% for each of NA and ESO. The primary affiliation of a PI on a proposal determines, which time contingent is used. Based on our ALMA proposal poll, we expect that most (solar) proposals will be submitted from Europe. Consequently, competition for European (=ESO) time might be much higher than the for the NA or EA shares.

PIs with a primary affiliation in a non-partner country have to compete for “Open Time”, which is by far the smallest and consequently oversubscribed contingent. Competition will be though.  

Solar continuum observations are handled as a non-standard mode. Any solar observing proposal thus competes with all other non-standard proposals (e.g., VLBI etc.). A maximum of 20% of the available time (3000 hours of the 12-m Array) can be allocated to non-standard observing modes, including solar observing. In other words, solar proposals compete with all other non-standard proposals for a maximum of 600 hours of the 12-m Array.

Offered capabilities for solar observing in Cycle 4

The Proposer’s Guide contains detailed information about what is and what is not offered for solar observing in Cycle 4. This information is also repeated on this webpage. Some important points:

  • Only the three most compact configurations are offered: C40-1, C40-2, C40,3
  • Proposals requesting only total-power single-dish observations will not be accepted. Please team up with an interferometric proposal if you are mostly interested in single-dish scans. The latter will be produced as a default component of all selected solar observations.
  • Only continuum observations in Bands 3 and 6 are offered but they cannot be used simultaneously. A proposal can contain any sequence of Band 3 and 6 but each science goal can only include one band. You should therefore define a science goal for Band 3 and Band 6 each in your proposal if you want (consequent) observations in both bands.
  • From Sect. B.5: "ALMA observations are comprised of one or more executions of a Scheduling Block (SB). The total execution time of an SB cannot exceed 2 hours, which will include the time overheads for bandpass and flux calibration. These calibration overheads amount to about 25 mins." In other words, after max. 1.5 hours observing a break for calibration (~half hour) is mandatory but observing could continue afterwards.

Proprietary period

There is a proprietary period of one year for ALMA data, counting from the date the data has been provided to the PI. However, a PI can distribute the data to further collaborators already during this period.

Published Mar. 21, 2016 7:12 PM - Last modified May 16, 2018 11:02 PM