Targets of Opportunity

Welcome to the Neil Gehrels Swift Observatory Target of Opportunity Web Site.

Response Urgencies:

• A "Highest Urgency" ToO will immediately page the Swift PI and Science Operations team, even in the middle of the night.
• "High Urgency" ToO requests will page the PI and Science Operations team immediately during working hours.
• "Medium Urgency" requests will be handled during daylight hours.
• "Low Urgency" requests will be handled at the daily planning meeting which is 9-10am Eastern Time (USA) M-F.

• Galactic or local-group supernova
• High-probability gravitational wave event
• High-probability neutrino event
• Highly exceptional GRB or SGR

Normal Planning Timeline:

Below is the typical schedule for producing and submitting the observing schedules. Please give a few extra days for submitting ToOs around the holidays.

All times are in Eastern Time (USA).
*Schedules are submitted in the mornings.

GI Cycle:

As of April 1st, 2021, Swift Cycle 16 (AO16) is officially closed. GI ToO programs from AO16 and earlier can no longer be triggered. We are currently accepting triggers of accepted Swift Cycle 17 (AO17) ToO programs.

Pre-approved ToOs:

ToO requests satisfying the trigger criteria for programs approved through the Swift GI program must be identified by filling in the proposal number at the bottom of the ToO Request page. This is necessary to trigger funding of your proposal.

GRBs:

ToO requests may be made to follow up Gamma Ray Bursts detected by other satellites. We do receive the GCN notices of such events, but appreciate knowing of special circumstances for which immediate Swift followup is desirable.

Tiled Observations:

Swift's tiling capabilities are aimed at quickly localizing astrophysical transients, such as GRBs and other transients, with positional error circles that cannot be covered by a single XRT 23.6 arc-min diameter field of view. More information on our tiling capabilities can be found here.

ToO Evaluation Criteria

(revised Mar 18th, 2021):

ToOs are approved by the Swift PI using the evaluation criteria listed below.

• Does not impair Swift's capability for GRB detection and follow up.
• Requires fast turn-around observations (one day to one month).
• Produces high impact science (publication to follow).
• Makes good use of Swift data, i.e. Swift data are a major component of the results.
• Requires unique Swift capabilities (response time or UV).
• Makes use of more than one instrument.
• Constraints: The Swift spacecraft can point anywhere in the sky except within 46 degrees of the Sun, 21 degrees of the moon, and 6 degrees of the orbit pole, which precesses slowly. To check target visibility, please use the Long Term or Short Term target visibility calculators.
• Anti-Sun Pointing: ToO targets located between 8 and 4 hours in RA from the Sun are much less likely to be accepted. ToO targets in this range may be accepted for scientifically compelling reasons, but are scheduled for limited exposure times of typically <4 ks per day (with 2 ks per day a standard value). The purpose of this restriction for ToOs is to keep the observatory pointing as much as possible toward the night sky to optimize ground-based follow-up observations of GRBs.
• Requestors that have a high and rapid publication rate (ATELs and papers) will be given extra consideration.

Swift's primary mission is to detect Gamma Ray Bursts and observe their afterglow radiation. Swift's rapid response capabilities make it an ideal observatory for a variety of transient astrophysical sources. This site provides a simple form for requesting Target of Opportunity observations.

Registration:

Anyone may request a Target of Opportunity. Requestors are asked to complete a New User Account Form for informational purposes and to simplify entry of future requests. Completion of the ToO Request Form requires a basic understanding of astrophysical sources and the capabilities of Swift's instruments. Information on the latter is available from the links for the XRT, UVOT and BAT. If you are uncertain of the nature of a celestial phenomenon you have witnessed, please contact your local astronomical society or one of the many astronomical publications for assistance in determining if a Swift ToO should be requested. Contact information is provided by Sky & Telescope and other publishers on their Web sites.

Submitting ToO Request:

Requests are relatively simple to complete. Swift's Burst Alert Telescope selects observing modes autonomously. The X-ray Telescope normally selects observing modes autonomously, but a specific observing mode (either WT or PC) can be requested in the "Science Justification" section if required. The UV-Optical Telescope uses pre-defined observing sequences. You may request specific UVOT filters and modes, subject to a safety check, or leave the selection to the Science Operations Team. Unless otherwise specified, UVOT observations will be performed using the "Filter of the Day" (either U band or one of the 3 UV filters). Special UVOT filter requests can by made in the text box titled "UVOT Filter Justification."

After you submit your request, you will receive an automated acknowledgement within a few minutes, followed by our evaluation and observation plan within one business day (24 hours for time-critical observations).

You must submit (a) a scientific justification and (b) feasibility justification in the text box titled "Science Justification" to facilitate evaluation of your request. Clear statements about (a) the result(s) to come from this observation, and (b) a numerical calculation about the feasibility must be given (countrate * obs_time yields the significance needed to achieve the result). For coordinated observations, (a) click that button in the "Requested Observations" section and (b) include the date/time windows of observation in the "Science Justification" section. This justification can include links to figures if they are essential to support your request. Science justifications can be viewed only by the Swift PI and operations team - they are not made publicly available.

Swift Team Contacts:

You may be contacted by the Swift Observatory Duty Scientist (ODS) for further information needed to schedule your request. If you need to contact the ODS to provide supplemental information regarding your request, please use the swiftods@swift.psu.edu email address, since the ODS is a rotating position and the individual who contacts you may not be on duty when you reply.

You may also be contacted by the Swift team to inquire about collaboration if your ToO observation is related to ongoing team research. You are free to reply or not to such contacts at your preference.

Data Rights:

Unlike most astronomy satellites, the data from Swift are all public immediately. This means that there are no proprietary data rights to data resulting from ToO requests. We therefore encourage you to analyze and publish your results as rapidly as possible following the completion of Swift observations.

Other information

For further information on Swift Target of Opportunity requests, please contact the Observatory Duty Scientist at swiftods@swift.psu.edu. The Swift PI can be contacted by phone in extremely urgent cases (301-526-9288). Note that high urgency ToO requests result in the Swift Science Ops Team and the PI being notified of the request immediately, so phone contact should not be necessary in normal circumstances.