Queued Service Observations with ESPaDOnS

Phase 1 Proposal Submission Instructions

Updated Aug 18, 2016

Table of Contents

A - Introduction

B - 2017A-specific information and news

C - NorthStar

D - Applicants

E - Justifications

F - Observing Requests

G - Target list

H - Additional issues

Z - Check list

A - Introduction [Back to Table of Content]

ESPaDOnS, the QSO mode, and the QSO SNR mode

ESPaDOnS is a high-resolution échelle spectrograph/spectropolarimeter fiber-fed from a Cassegrain module including calibration and guiding facilities, as well as an optional polarization analyzer. This instrument offers a complete optical spectrum (from 370 to 1,050 nm) in a single exposure with a resolving power of about 68,000 (by using a slicer in a 3-slice configuration, in spectropolarimetric and 'object+sky' spectroscopic mode) and up to 80,000 (by using the slicer in a 6-slice configuration, in 'object only' spectroscopic mode).

Observers can use the following modes:

For details about that instrument, please see its webpage. For additional questions, please contact Nadine Manset (manset -=at=-

ESPaDOnS is offered under the Queued Service Observing (QSO) mode only. The main concept behind the QSO scheme is to perform observing programs only during sky conditions or time constraints required to meet their science goals, as defined by the investigators. This can only be achieved if the programs are all grouped together in a database and are selected appropriately according to a set of constraints, rules and sky conditions. Programs are then carried out by a well trained, local team of observers in a service mode (i.e. investigators are not present at the observatory).

Before submitting a CFHT proposal, please read the short tutorial How QSO works at CFHT. [Keywords: QSO, Regular/TOO/Snapshot programs, Deadlines, NorthStar, Exposure Time Calculators, Technical Evaluations, TAC, Ranking, QSO grade, C programs, Snapshot programs, PH2, Observations, Sky conditions, Calibrations, Night Reports, Data reduction and distribution, Proprietary period, QSO rules, Contact information.]

Starting in 2017A, the QSO SNR mode is used by default for all programs except non-sidereal observations, short exposures (<30s), or observations that require precise timing. To opt out of the SNR mode, include a justification in your proposal.

NorthStar Phase 1 Tool

CFHT is using the NorthStar Phase 1 tool. NorthStar is used by Principal Investigators (PIs) to submit their proposal(s). All new PIs must register as new NorthStar users; the registration page offers a Help file if assistance is needed. The login information from NorthStar is NOT transferred to PH2. After login in, Help on how to use NorthStar is available on each page.

For technical information regarding ESPaDOnS, please see the ESPaDOnS page.

B - 2017A-specific information and news [Back to Table of Content]

Pressure from Large Programs

Please note that during the semester 2017A, Large Programs are using the following RA ranges:

Following a SAC 2014 recommendation: "Beginning with the proposals submitted in the March 2010 round, when CFHT performs its technical evaluation (which is then communicated to the TACs), CFHT will flag any proposal which has conflicts in RA and observing conditions with an existing LP. During their ranking process, the national TACs which are participating in both the conflicting PI programs and LP(s) will provide information to CFHT on the relation and priority of each of those, although agency balancing will continue to be the first decision point for CFHT" (see SAC recommendation #12 from Nov 2009).

QSO SNR mode

Starting in 2017A, the QSO SNR mode is used by default for all programs except non-sidereal observations, short exposures (<30s), or observations that require precise timing. To opt out of the SNR mode, include a justification in your proposal.

Your proposal (and later PH2) must include the SNR needed per pixel and per exposure. This information is needed for the technical evaluations.

Mandatory ETC calculations

PH1 mandatory field
The PH1 system has been changed to have users include the values of the exposure time calculators into their proposals. Proposals cannot be submitted if this field is not filled. This is not counted toward the page charge. Here is how to proceed:

Effect of (normal) mirror coating degradation on exposure times

Due to (normal) mirror coating degradation, there is a loss of flux of about 20%. The figure below shows the flux as a function of wavelength for the same star (the standard HR 3454), observed in Dec 2014 and Feb 2016 under the same conditions (photometric sky and IQ~0.7"). The spectrum of the flux ratio is normalized on the plot (because it is very sensitive to seeing), so it is not an absolute zero point loss.

The figure shows that the coating degradation is chromatic. Exposure times should be modified from those of the ETC accordingly.

Snapshot programs

All agencies are invited to encourage their community to submit snapshot programs. These programs must be able to accept an Image Quality worse than 1.2" or significant levels of extinction. Snapshot programs are used not only during bad weather conditions but also to fill gaps in the queues when no A, B or C program are available or suitable. Snapshot programs are not counted toward an agency's allocation.


During 2009B, ESPaDOnS has been upgraded with a new triplet lens and a new Atmospheric Disperson Corrector, which brought the overall crosstalk below 1%.

Non-sidereal observations

IMPORTANT NOTE : The non sidereal tracking option (i.e., following a target with non-sidereal rates, but without guiding on stars) is offered, but the telescope shows drifts on exposures of 2-3min or longer. If you have questions or concerns related to this option for your proposal, please do not hesitate to contact the QSO Team (qsoteam -=at=-

Page limit for Canadian proposals

For Canadian proposals: the Science justification is now limited to 2 pages, and the Technical justification to 1 page. For all other agencies, the page limits are 3 pages and 2 pages respectively.

For more information about the submission of your ESPaDOnS QSO proposal(s), contact the QSO Team qsoteam -=at=-

C - NorthStar [Back to Table of Content]

NorthStar is the Phase 1 tool to submit proposals. This tool does not use Latex. The scientific and technical justifications, along with references and figures, are uploaded as PDF files, which may be prepared by the PIs on any software they may wish to use. Figures and references may be included with the Scientific and/or the Technical justifications.

Also note the following regarding the list of targets:

D - Applicants [Back to Table of Content]

For each proposal, there can only be one submitter. However, co-I may be invited to view and edit the proposal too. The PI may also be different than the proposer (contact author). Note that if a proposal is accepted, it will get registered in PH2 under the PI's name, not the name of the contact author or the submitter! Each program belongs to its PI and requires the PI's login information in PH2.

E - Justifications [Back to Table of Content]

The Scientific and Technical justifications must be uploaded as PDF files, and have a limit of 2 and 1 page respectively for Canadian proposals, and 3 and 2 pages respectively for all other agencies.

Please use the CFHT ESPaDOnS + Olapa exposure time calculator to calculate the exposure time for each of your target and justify the total integration time requested. Do not use the original ETC from the Toulouse website, because it has not been updated for the new detector Olapa. In your technical justification, please mention your required signal-to-noise ratio per pixel, per exposure, in the intensity spectrum, and the corresponding wavelength. This will remove any ambiguity on your quantitative goal, show consistency with the ETC, help the feasibility review, and potentially prepare your work for the next phase.

Starting in 2017A, the QSO SNR mode is used by default for all programs except non-sidereal observations, short exposures (<30s), or observations that require precise timing. To opt out of the SNR mode, include a justification in your pr oposal.

F - Observing Requests [Back to Table of Content]

For ESPaDOnS, you may select QSO Regular programs or QSO Snapshot program. QSO Regular programs include all of the normal QSO programs, with fixed or Solar System objects. Target-of-opportunity (TOO) programs submitted at the same time as all other CFHT proposals may simply be submitted as a QSO regular program. Snapshot Programs must request bad sky conditions and accept a low completion level.

The definition of a snapshot program for ESPaDOnS is the following:

  1. A snapshot program describes valuable science to be obtained on targets observed only in the worse sky conditions (seeing larger than 1.5", and/or high extinction above 2mag)
  2. A snapshot program will be scientifically useful even if the completion is low
  3. A snapshot program preferably requests simple observations (i.e. sidereal tracking, no monitoring)
  4. A snapshot program should preferably include short blocks of observations
  5. The time allocated for such programs is not accounted for in the statistics of time spent for the different Agencies
  6. The proprietary time for the data is 3 months following the end of the semester.
Note that the chance of such programs to be executed, even partially, during a semester can be quite high.

For ESPaDOnS, the seeing is not a fundamental constraint, although it plays an important role in the amount of light that can get into the entrance fiber. The exposure time calculator gives a clear idea on the effect of the seeing on the S/N obtained on a given target. The table below describes the seeing statistics on Mauna Kea. These data are for the R-band and were taken with FOCAM at CFHT between 1993-1995 (more recent statistics confirm these values).

Image Quality (IQ) Frequency
IQ 1.0" 80%
1.0" < IQ 1.5" 15%
IQ > 1.5" 5%

For your information, the table below gives the average weather statistics for Mauna Kea. Note that the "A" semester is usually more affected by bad weather; time lost during the first few months of the winter can be as high as 50% and even more.

Sky Conditions Frequency
Usable Nights ~70%
Lost to Weather ~20-30%
Usable Photometric Nights ~50%

In queue mode, the time requested is in HOURS.

  1. If the total time of your program is fractional (e.g. 32.4 hr.), please indicate so (.4 hr in a queue mode is possible).
  2. In your calculation of integration time, only the exposure time and overheads should be included. The overheads depend on the readout speed selected (no binning is offered) for each exposure and additional operational overheads: fast (40 sec), normal (60 sec), slow (85 sec). Of course, to acquire one Stokes parameter in polarimetry mode, 4 exposures are needed; calculation should be done accordingly.
  3. Slewing and acquisition SHOULD NOT be accounted for in your calculations.
  4. CFHT provides instrumental calibrations (biases, flats, comparison exposures) but does not provide any on-sky calibration, such as spectrophotometric standard stars, twilight spectra, or radial velocity standard stars. Those MUST be included in the proposal and in the time requested. The "Calibration Requirements" box may be used to present those calibrations.

Bright stars can saturate the detector. Please use the exposure time calculator and make sure you do not get any Saturation warning!

For various reasons (QSO internal constraints, cosmic rays, overall strategy, scheduling flexibility), single polarimetric exposures + their overheads cannot exceed 1800s, and single spectroscopic exposures should not exceed 1h.

Any time constraint or scheduling constraint must be indicated in the proposal: the need for a certain number of consecutive nights, the need for long blocks of time (for example, 8 hours) per night, the need to coordinate CFHT observations with observations taken by another telescope, etc.

By default, the proprietary period of QSO data extends to 1 year + 1 month starting at the end of the QSO semester. If an extension is requested and approved by TAC, a new date will be set for this program through the QSO system. The release date for the data is indicated in the fits headers by the keyword REL_DATE. For snapshot programs, the proprietary time is 3 months following the end of the semester.

G - Target list [Back to Table of Content]

Besides a list of targets with coordinates, ESPaDOnS proposals must include the Magnitude of each target. This information will be used to evaluate the technical feasibility of each proposal.

H - Additional issues [Back to Table of Content]

The Additional issues tab is used to link various proposals together, if need be.

Z - Check list [Back to Table of Content]

Before submitting your proposal, please make sure that:

Need More Information?
Contact the QSO Team at
qsoteam -=at=-