2. Observing cycles

In this fourth AO cycle, 65% of observing time is available for Indian AO proposals and 20% of observing time is for International AO proposals.  5% time is allotted for Targets of Opportunity (ToO).  Rest of the 10% time in this cycle is allotted for collaborators and calibration.

2.1   AO cycle

AstroSat is operated in a pre-planned manner i.e proposers are not present at Mission Operations Complex during the execution of their observations.  Thus, all observations must be specified in full details in advance.

  • The percentage of observing time for executing AO proposals during October 2018 – September 2019 is 85% and is termed as fourth AO cycle.
  • Out of 85%, 65% time is exclusive for Indian proposers as Principal Investigators (PIs) to utilise AstroSat observatory time. They could be interested  researchers, scientists and astronomy community at large, involved in scientific research in the field of astronomy and are equipped to submit proposals as Principal Investigators (PIs) for specific target observations with necessary scientific and technical justification and can analyse the data, if the target is observed based on approvals. In addition, 20% of the time is for international proposers from the global astronomy community. 
  • All the selected AO proposals will be inserted into the observing schedule.  However, few observations approved in this AO cycle may be scheduled outside of the above period, in case there is operations requirement, which will be provided by AstroSat Mission.
  • Proposers are requested not to duplicate any of the planned observations and should carefully justify duplications if any, with performed observations. Proposers have to check the list of objects and instrument parameters for observations already/ being carried out using AstroSat. A Red book containing these targets will be made available in the ISSDC website. Proposers wishing to observe any of these targets should justify why it is important to do so and what additional information will come from the proposed observations. See also section 4.
  • Checks for duplications will be performed by ATAC while processing the proposals during the scientific review.

2.2  Targets of Opportunity (ToO) cycle

  • Proposals that require observation of phenomenon like outburst of a supernova or nova, observation of a new transient source or X-ray nova or study of characteristics of a source when it makes transition to a different state etc. and for which one cannot predict in advance the time of occurrence, must be submitted as ToO proposal and they will be reviewed by a separate ToO Committee.
  • A ToO cycle is always open for submitting proposals at present for any proposer. A provision of 5% observing time is reserved for ToO proposals. 
  • Data of observations made using a ToO proposal during the allotted ToO time will be made public immediately. 
  • If this time is not fully subscribed, it may be added to the time for the AO proposals.
  • Anticipated ToOs are ToOs whose source position is known but time of observation is not known or unpredictable.  The proposal for anticipated ToOs can also be submitted through APPS, which will be reviewed by ATAC committee.  The scientific justification needs to be really strong to clear the proposal and also has to get priority “A” for acceptance (refer APPS proposer's guide available in ASC website for details on anticipated ToOs and priority ranking for proposals).  However  when  the event occurs,  a  ToO  trigger  proposal  by  the PI  of  the original proposal has  to be  submitted under ToO  cycle to schedule the proposal. The data rights are same as that for AO proposals.
  • ToO and Anticipated ToOs under UVIT safety check for targets in fields not covered by GALEX is now included in this cycle.  For further details, check section (16) of AstroSat proposer's guide v1.2.