Subaru Log HSC Queue Mode Title

Updated on 2016-08-08
Important Notice for S17A

  1. HSC queue mode is opened for Normal and Filler programs.
  2. Time critical program is supported for Normal Program in S17A.
  3. No cadence program is supported in S17A.
  4. HSC queue mode programs will be executed in queue observation nights and in dead time ('Sukima time') in HSC classical mode programs. For this purpose, no additional target request in HSC classical observation is allowed.


What is HSC queue mode?

Queue mode is non-visitor mode observation, i.e. the observations are carried out by observatory staffs without a direct involvement of investigators (PI or Co-Is). The observation will be performed based on the rank of the observation program, the priority of the target, observing conditions (seeing, transparency, moon phase, moon distance, airmass of target), telescope slewing time, current instrument configuration (filter etc.) Appropriate selection of science objects with proper observing conditions allows to increase the effectiveness of the observation and data quality for better scientific outcomes.

Program selection and preparation consist of two parts, namely, Phase 1 and Phase 2. Phase 1 is the submission of proposals. PI should describe the observing condition constraints such as acceptable range of seeing, transparency, moon phase etc. in their proposal. Phase 2 happens after the proposal's acceptance by TAC (Time Allocation Committee). The PI will be notified and asked to prepare and submit details of their observation plan (as a list of observing blocks) before the beginning of the observation semester.

Subaru Telescope will manage the scheduling and execution of queue programs. The obtained data will be delivered to PI after the quality assessment.

Below, we summarize each step of the queue-mode observation and provide useful references. For the datail, please see HSC Queue-Mode PI's Document (PDF, HTML).

Summary of Procedure

What should be done by PI
What should be done by the observatory
Phase 1

(CfP period)
Aug.-Sep. (A semesters)
Feb.-Mar. (B semesters)

Proposal submission.

The PI should submit a proposal via ProMS (Proposal Management System) as they do for classical programs. The observing condition constraints such as seeing, transparency etc. should be specified in the proposal.

  1. Announce Call for Proposals
  2. Receive proposals via ProMS
Phase 2

(After TAC)

Nov.-Dec. (A)
May-June (B)

Submit observing blocks (OBs).

OB is the smallest unit of observations in queue mode. Using tools Subaru Telescope provides, the PI should complete the OBs before the deadline.

  1. Request the preparation of OB list to PIs of the accepted programs.
  2. Assist PIs to complete OBs. Check submitted OBs and give feedback.
  3. Check the probability of the observation completions for the semester. Support astronomer (SA) may ask the PI to relax the observing condition constraints to increase the probability of obtaining the data.

Observation will be executed by observatory staff.

After the data acquisition the PI will be notified which OBs have been observed.

  1. Scheduling and execution of queue mode will be done by Subaru Telescope.
  2. SA will make an Initial Quality Assessment (IQA) during the observation.
  3. During the day-time, Final Quality Assessment (FQA) will be performed to make a decision whether the OB is completed or it should be returned to the queue.
  4. 4. Subaru Telescope will inform the PIs about the progress of their programs.
Data Delivery

When the data are ready, the PI will be notified with an instruction.

Subaru Telescope will provide the raw science data as well as associated calibration data and observation logs.


Phase 1

Proposal submission is made through the Proposal Management System (ProMS). ProMS has been updated to accommodate HSC queue mode. Please select 'HSC Queue' for Normal program or 'HSC Filler' for Filler program, then follow the instruction in ProMS.

Select 'HSC Queue' for Normal program or 'HSC Filler' for Filler program.

Important Policies

  1. Total observing time does not include any overhead time. PI does not need to consider any overhead - readout time, telescope slewing, standard field (SDSS field), etc - when he/she requests total observing time for HSC queue mode.
  2. The observing request time should be set in unit of nights with the conversion relation ( 0.14 night = 1 hour).
  3. Observation constraints in the proposal (item 13) should be the strictest value for each constraint : seeing (upper limit), transparency (T; lower limit), Moon phase (brightest allowable phase), Moon distance (lower limit), and airmass (upper limit). For example, if one target requires seeing ≤ 0.5" while the others can be made with seeing ∼ 1.0", PI needs to set the seeing constraint as ≤ 0.5 in item 13 of the ProMS. Moon distance from the target should be larger than 30 degrees. Note that the moon-target separation is automatically relaxed to 30 degrees in dark time.
  4. The default airmass constraint is 2.0. The PI can specify the upper limit between 2.0 and 3.0 if he/she wishes to allow observation in low elevation. The PI cannot specify the airmass constraint smaller than 2.0.
  5. Weather may change during observations, so a tolerance of 0.1" for seeing and 20% margin for transparency (T) will be applied. For example, if the PI set observational constraints as seeing ≤ 0.8" and T ≥ 0.90, then the OB will be executed only when seeing ≤ 0.8" and T ≥ 0.90. As a result of observation, however, if the observed frame has seeing ≤ 0.9" and T ≥ 0.72, it will be considered as acceptable.
  6. Time critical observations are supported in S17A for Normal program only. Please put "Time critical" in Comments in the Box 12, and provide sufficient information on the time constraint (i.e., acceptable time windows) in Box 13 of Application Form of the proposal for S17A. If different constraints apply to different targets/fields, please define the constraints in the list of targets, by adding comments in the "Magnitude" field. Multiple time windows are allowable. The time constraints of the windows should be clearly described, preferably in UT time. Note that the chance for the OBs to be observed becomes higher by specifying the time windows as relaxed as possible. The time windows are limited by the number of queue nights in the semester.
  7. Cadence observations, which need the regularly repeated series of the observations with a time interval, are not supported in S17A.
  8. In principle, filler programs will only be executed under poor conditions with either bad seeing (≥ 1.2") or bad transparency (≤ 50%) with cirrus clouds. Higher priority should be given to normal open-use programs (GRADE A, B, C) and Subaru Strategic Program (SSP). Only when there is no any other program to be executed in the time slot, filler programs may be selected and observed. [Filler Program Form]

Statistical Information for Observing Condition Constraints

Please set the observing condition constraints to achieve your scientific goal. In the ProMS, PI needs to set the strictest value for each observation constraint. The following information is provided as references to find the typical frequency of seeing and transparency conditions, based on the recent observations of HSC.

Cumulative probabilities of seeing and transparency

Seeing (in arcsecond)
<  0.616
<  0.736
<  0.924
Transparency (0 - 1; 0=worst, 1=best)
<  0.811
<  0.928
<  0.953
* Seeing was measured from Mar. 2014 to Jul. 2015 and transparency was measured for Jan. - Jul. 2015 based on HSC data.

  Image quality statistics for May 2000 - Sep. 2006 at the Subaru Telescope's foci
  Seeing statistics from Auto Guider for May 2000 - Nov. 2010

Estimation of Total Exposure Time

Please use HSC Exposure Time Calculator (ETC) to estimate the S/N and total exposure time for your targets.

Target Field Check

Please check your important target is not on bad CCDs or columns or gaps between CCDs.

SDSS Field Check

Please check whether your target field is covered by SDSS or not. If not, please find an SDSS field close to your target for the calibration of your science target. We recommand to avoid narrow strip pattern region in the maps below.

Phase 2

In Phase 2, for the accepted proposals, Subaru Telescope will ask the PIs to prepare and submit Observing Blocks (OBs).

  1. Please contact queue (at) if you have any questions. support astronomers (SAs) will help your preparations.
  2. The each OB is the minimum observation unit. The maximum length of on-source exposure time in OB is limited to 100 minutes. We recommend making length of each OB shorter, as a shorter OB has higher probability of being executed than a longer one.
  3. Subaru Telescope provides Phase 2 tool. In S17A it is a simple spread sheet file as linked below.
  4. Check OBs with Web check tool. If there is no error, submit the spreadsheet file of OB through Web check tool.
  5. Subaru Telescope will check the submitted OBs. Also, we will check probability of the observation completions for the semester. SAs may ask the PI to relax the observing condition constraints to increase the probability of obtaining the data. If the relaxation is allowable for your program, please re-submit your OB list with relaxed conditions.

The deadline of Phase 2 OB submission for S17A is 5pm on December 9th, 2016 (JST).

A plugin for the Ginga image viewer to visualize a field with a dither on the HSC CCD plane.

Important Policies for Phase 2

  1. Each OB must have on-source exposure time shorter than 100 minutes.
  2. Each observing condition constraint for an OB must not be better than that given in the original proposal (Phase 1).
  3. All targets must be listed in the original proposal. Neither change nor addition of targets is allowed in Phase 2.
  4. Each OB code must be unique. OB codes cannot be changed once the observing semester starts, even if the PI is asked to relax constraints.
  5. For a scientific target without SDSS imaging data, the PI needs to provide a SDSS field for the calibration.
  6. Although the amount of actual observing time for a program will be equal to or shorter than the time allocated by TAC, the PI may include OBs with the total observing time larger than the time allocated by TAC. Depending on the extra OBs included, this may improve the possibility of execution, but please note that the priority of the targets will not be always guaranteed and the program will be considered as 'completed' when the all of the allocated observing time by TAC is consumed.

Observation and Completion Status

  1. Observatory staffs will perform observations based on the observing condition constraints given by PIs, rank of the program, priority of targets, telescope slewing time, HSC filter, etc.
  2. SA will carry out Initial Quality Assessment (IQA) during the observation to check the quality of data.
  3. A Final Quality Assessment (FQA) will be made by SAs in the days following the observation of the OBs
  4. Subaru Telescope will inform the PIs about the progress of their programs.
  5. If the progress of a program is slow, Subaru Telescope may contact the PI for the relaxation of the original observing condition constraints in order to increase the selection probability of the program in queue scheduling.

Data Delivery

Please contact to if you have any questions.

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