NuSTAR Bringing the High Energy Universe into Focus


For Proposers

NuSTAR has been approved to continue operations through 2020 (subject to review by the 2019 NASA Astrophysics Senior Review of Operating Missions) including a Guest Observer Program.
Opportunities to propose for NuSTAR observing time
2017-10-06 NuSTAR Guest Observer - cycle 4 (Propose here!)

Solicitation for proposals released.

Proposal due date is 4:30pm EST on January 19, 2018 via the NASA-HEASARC ARK/RPS system. For more information visit:


New in cycle 4: proposals for joint NuSTAR/Swift programs will be accepted up to a total of 300 ksec of Swift observing time. Proposers are strongly encouraged to carefully read the Swift/NuSTAR memorandum of understanding.

NuSTAR cycle 4 observations begin on 2018-06-01

The total amount of time allocated to Guest Observations is 9.5 Ms (~50% of the total observing time per year) including up to 6.5 Ms of observing time awarded to selected NuSTAR GO program investigations. It is anticipated that approximately 50 investigations will be selected for implementation in each NuSTAR GO cycle.
Of the remaining time (~ 3 Ms):
  • up to 1.5 Ms of NuSTAR observing time is expected to be awarded to joint NuSTAR/XMM-Newton proposals submitted to the XMM-Newton Cycle 17 Call for Proposals. The list of accepted proposals for cycle-16 is available on the XMM-Newton OTAC results website.
  • up to 1.0 Ms of NuSTAR observing time for joint NuSTAR / Chandra observing projects submitted to the Chandra Cycle 19 Call for Proposals. Note that this includes up to 0.5 Ms reserved for V/LP programs. See CXC website for Cycle-19 peer review recommended programs.
  • up to 100 ks of NuSTAR observing time for joint NuSTAR / INTEGRAL observing proposals submitted to the INTEGRAL Cycle 16 Call for proposals. The deadline for INTEGRAL AO-16 proposals will be in March, 2018.
  • up to 300 ks of NuSTAR observing time for joint NuSTAR/Swift proposals is expected to be available starting in Swift cycle-14, with proposals due on 2017 September 28th.
  • As a service to the community "snapshot" (1 - 2 ks) observations are performed by NASA’s Swift mission for most NuSTAR observations (including GO programs).
For the most complete list of planned and observed targets, as well as any ToOs that may be triggered before the beginning of Cycle 4 observations on June 1st 2018, please refer to the NuSTAR  Master Catalog at the HEASARC, which may be queried using either Browse or Xamin and the list of approved NuSTAR  ToO programs available on the NuSTAR  SOC website.
The remaining 50% of the observing time will be allocated through the NuSTAR  project as follows:
  • NuSTAR  legacy survey observations (~ 25% of the total observing time)
  • NuSTAR  PI discretionary time, including unanticipated ToO observations open to the scientific community (~ 15%)
  • Calibration observations, engineering tasks, and resolving operational issues (~ 10%).
Please see the NuSTAR  HEASARC Page for the latest information about NuSTAR. We've also provided useful links on the left including links to the NuSTAR observation constraint checker, the NuSTAR simulation toolkits, and details of the approved NuSTAR  legacy survey programs.