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Department of Space, Indian Space Research Organisation


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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