The JCMT operates on a two-semester basis for PI time. Semester A running from February 1st to July 31st and Semester B running from August 1st to January 31st. The deadline for Semester A proposals is typically mid September. The deadline for Semester B proposals is typically mid March. The Call for Proposals usually open one month before the deadline.
In addition to the biannual semesters of the “Regular” queue, an “Urgent” queue, specifically for science proposals of an urgent nature, remains open for submissions throughout the year.
The East Asian Observatory is opening a 25B semester supplemental call for proposals that request observing time with heterodyne instruments at the James Clerk Maxwell Telescope (JCMT). This special call requests observations to be carried out in the remainder of the ongoing 25B semester, until January 31st 2025, and is being opened due to expected SCUBA-2 unavailability for the rest of this semester.
Heterodyne only Supplemental Call for Proposals – Semester 25B
The JCMT welcomes proposals that utilize the range of RAs observable from October 2025 to January 2026 during night time operations, roughly 18:00 to 06:00 HST.
We particularly welcome proposals in weather bands 1, 2, and 3, where we have significant available time. Please note in the current queue we have significant pressure at approximately 6 hours RA for weather band 1, the rest of the observable RA range has less pressure in band 1 to 3. The approximate observable RA ranges with less pressure are:
- For weather band 1: from 0 to 5, 7 to 13 hours and 19 to 23 hours.
- For weather bands 2 and 3: from 0 to 13 hours and 19 to 23 hours.
- For weather band 4: from 0 to 6 hours, 8 to 13 hours, and 20 to 23 hours.
- For weather band 5: from 0 to 6 hours, 8 to 11 hours, and 20 to 23 hours.
The time to be allocated in this call for proposal is around 350 hours across weather bands.
Large programs can propose supplemental observations, provided that the PI meets the eligibility requirements and the time requested is under the 150-hour maximum. This is not, however, a call for new Large Programs.
Proposal submission is via the JCMT proposal handling system, Hedwig. For full details, and for proposal submission, please see:
https://proposals.eaobservatory.org/jcmt/semester/27/supplement
The announced call for proposal closes on October 4rd, 01:00 UTC.
PI eligibility for this Call has the same criteria as for the 25B PI call for proposals, please see:
https://www.eaobservatory.org/jcmt/proposals/eao_eligibility/
If this is your first time using Hedwig, you should use the ‘Log in’ button to generate an account. There is a Hedwig ‘Help’ facility at the upper right corner of each page, and individual Help tags in many other places. Note that Hedwig also allows a user to create copies of their previous approved proposals that were not completed (‘Continuation Request’), in order to simplify the process of proposal resubmission.
Please contact us at helpdesk@eaobservatory.org if you have any questions.
Thailand Call for Proposals – Semester 25B
The East Asian Observatory is now accepting proposals from Principal Investigators (PIs), affiliated with a Thailand institution only, for a special Supplementary Call for Proposals for Semester 25B, at the James Clerk Maxwell Telescope (JCMT). Proposals should be submitted via the JCMT proposal handling system, Hedwig. For complete details and to submit your proposal, please visit:
https://proposals.eaobservatory.org
This Call for proposals closes on July 27, 2025, 01:00 UTC. The Hedwig system permits the submission (and editing) of proposals until this deadline.
There are 24.5 hours available for this call, and proposals for weather band 4 are especially welcome. Please note the pressure plot below: weather bands 1 and 2 have no remaining time at the popular R.A.
If this is your first time using Hedwig, you should ‘Log in’ and generate an account. There is a Hedwig ‘Help’ facility at the upper right corner of each page, and individual Help tags in many other places. Note that Hedwig also allows a user to create copies of their preexisting proposals, in order to simplify the process of proposal re-submission.
Please contact us at helpdesk@eaobservatory.org if you have questions about the Call for Proposals.
- Check the JCMT Science Archive to see if data already exists!
- Check if data already exists on your object:
- use the new general clash tool to check if the data already exists on your target (looks through all publicly available data).
- Are you eligible to submit as PI ? – check your nationality / affiliation here
- JCMT Proposal Collaboration rules are described here
- Proposal Submission
- Preparing justification files
- Submissions Checklist
- Closed calls for proposals
or – – if you are ready to go: login to Hedwig. Good Luck!