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Activation of Target of Opportunity Observations
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Scheduling ToO Observations
Gemini North and South are accepting triggers for approved
"Target of Opportunity" or ToO programs as described in the Call for Proposals. We
recognize that many ToO programs require follow-up observations on
various timescales. Every effort will be made to complete these
observations but due to schedule (and weather) constraints this cannot
be guaranteed.
ToO Trigger Types:
- "Standard" triggers:
observations that, once triggered, can be executed more than 24 hours in the future. This is essentially identical to the
normal queue mode except that the targets are not known in
advance. Thus, observations will be placed in the queue based on
science rank and observing conditions constraints. If you want a
triggered observation to be considered under this mode, please specify
the "standing" period and the minimum/maximum length of the
interruption when triggering and fill in the timing constraints in the
Observing Conditions component. The PI will be notified if the
telescope is not available within that time frame, and will be given
the option to change his/her trigger.
- "Rapid response"
triggers: observations
that need to be done within the next 24 hours. The minimum
response time is about 20 minutes and these triggers can interrupt
ongoing observations. Each semester only a few
programs are allocated "Rapid Response" status by the ITAC. Details of
this mechanism are given below. Rapid response observations are only
executed during multi-instrument queue nights. The Gemini
North and South schedules show the science and engineering blocks
available; the schedule is subject to change at short or no notice.
Daily information about instrument availabilities and
configuration can also be found on the schedules page. Please
contact your program's Contact Scientist or the Instrument Scientist
if you need more detailed information on the availability of the
telescope during a specific period.
All
types of ToO observations can be prepared and submitted using the
standard fetch/store operations of the Observing Tool (OT). It is also possible to trigger
observations by sending a Uniform Resource Locator (URL) with all the
observation information to secure web sockets on the observing database
machines. Template observations in the programs are copied,
populated with the target and guide star information, and then
triggered.
Phase II Preparation
The
basics of ToO Phase II preparation
are the same as for regular queue programs. However, in this case
the PI needs to define template observations that will be used once the
targets are known. For programs with standard triggers that
require a limited set of instrument modes, PIs should prepare
templates similar to normal Phase II preparation. Programs that
observe more transient objects (e.g. SNe, GRBs) often use many
instrument modes so have to have more triggering options. For
these programs the contact scientist will often copy a set of standard
templates into the program. Please ask your contact scientist for
additional instructions.
Template observations should be made for each
instrument configuration that will be needed and should be stored in a
folder called Templates. This template observations should include:
- Science target acquistion (with matching PA and FPU-long slit or
IFU-for the Science observation)
- ToO type (only possible for programs with Rapid ToO status, see below)
- Science target (dummy) <-- can leave as (0,0)
- Guide star (dummy) <-- also could be left as (0,0)
- Complete instrument configuration
- Offset or instrument sequences as needed
- Observes
- interspersed GCAL flats and arcs as necessary
After being checked by NGO and Gemini
staff, trigger template observations will have their status set to
"On Hold" and the priorities set to the usual High, Medium, or
Low. PIs should FETCH their
programs and wait for the triggering event.
In
the 2008A OT the ToO observation priority was removed. Each program now
has a ToO status based on the option ("None", "Standard", or "Rapid")
approved during Phase I. The status is given at the main program level.

The
TOO status is also shown at the observation level for programs that are
allowed to trigger TOO observations. Programs with Standard TOO status
can only trigger Standard TOOs while programs with Rapid TOO status can
trigger either kind.
Standard TOO program

Rapid TOO program

Only one
unique template for each configuration should be defined even if
more than one observation with a given configuration may be triggered
on a given night. If the URL-based triggering mechanism
described below is not going to be
used then an Observing Tool "Note" should be used to ask
the Gemini contact scientist to make a number of copies of each
template and leave them all at On Hold.
Triggering an
Observation
Prepare
observation
In most cases these steps are carried
out using the Observing Tool. If URL-triggering is used then much of the preparation is done in software
external to the OT that formats a URL string with all the required
information. Scripts for automatically finding guide stars, formatting
the URL, and submitting it are under development and the PIs for TOO programs can obtain them by contacting Bryan Miller
(bmiller
gemini.edu).
- Prepare a finding chart
- Check Gemini web pages for available instruments and
configurations
- Fetch program if not using the URL-based rapid response
triggering
- Select observation template(s)
- The template(s) must have status "On hold"
- If not using URL triggering - NEW
- Copy the template(s) to a new folder. The new observations will have status "On hold".
- Edit the new observations according to the guidelines below.
- Update target component
- Fill in target name and coordinates
- Update instrument component
- Exposure time
- Central wavelength (if appropriate)
- Position angle (if needed)
- Update timing constraints if necessary. If
no constraints are entered then Rapid ToOs will be given a 24 hour
timing window and Standard ToOs will be given a 1 week timing window
from the time of the trigger. - NEW
- Prepare note with extra details of the observation. For Rapid Response triggers the notes should include:
- Time of slew (UT), either
- Slew immediately
- Slew when convenient within the next M minutes
- Slew as close to HH:MM UT as possible
- Slew within T hours after obsid [N] complete
- Slew before time (UT) up until when the observation should be
active
- Designated contact information
- Name of contact person
- Phone number
- Video IP (if available)
- e-mail address
- Acquisition information
- URL of finding chart if not submitted as a File Attachment
- Weather caveats and other information
Submit observation
- OT triggering
- Change the status of the observations to be triggered from
"On hold" to "Ready."
- Store the program to the Gemini database.
- Fetch
the program. Any default timing windows may not appear until the
program is fetched again. We recommend fetching the program after each
store to avoid overwriting the timing windows. - NEW
- URL triggering
- The PI software sends the URL string to the appropriate web
socket.
Data Collection and Packaging
For Standard triggers the observations will be scheduled at the appropriate time
in the queue. For Rapid Response triggers, the observers are
notified of the triggers immediately and respond according to the
timing instructions given. If the observers have any questions
about the observtion then they may get clarification from the PI
contact given in the note. If the observation cannot be done then
the reasons will be added to the note.
Raw data files usually arrive
at the Gemini Science Archive within a few minutes of being taken and
are accessible by the PIs. For Rapid Response programs the
observer will send an e-mail to the PI contact announcing that data is
available.
Last update January 2, 2008; Bryan Miller and Kathy Roth