NuSTAR Bringing the High Energy Universe into Focus


For Proposers

NuSTAR has been approved to continue operations through 2025 based on the outcome of the 2022 NASA Astrophysics Senior Review of Operating Missions (the report pdf file is available here) and includes a General Observer (GO) Program.
Last updated:   2023-11-09
Opportunities to propose for NuSTAR observing time




NuSTAR  cycle-10

Up to 6500 ks of NuSTAR observing time for standard proposals (< 500 ks) and 2000 ks of NuSTAR observing time for large proposals (> 500 ks) is available.

Joint observing time is available for XMM-Newton (up to 1500 ks), Gehrels-Swift (up to 300 ks), and NICER (up to 250 ks) is also available in the NuSTAR AO program.

Proposal due date:   Thursday January 25th, 2024   4:30pm EST

for observations beginning June, 2024.

Submit proposals using HEASARC/ARK 


Chandra  cycle-26

Up to 500 ks of NuSTAR observing time is available.

Proposal due date:   mid-March, 2024

for observations beginning January, 2025


The NuSTAR GO program

The total amount of time allocated to GO observations is 11.3 Ms (~70% of the total observing time per year) including up to 8.5 Ms of observing time awarded to selected NuSTAR GO program investigations. It is anticipated that approximately 80 investigations will be selected for implementation in each NuSTAR GO cycle.
Of the remaining time (~ 2.8 Ms):
  • up to 1.5 Ms of NuSTAR observing time is expected to be awarded to joint NuSTAR/XMM-Newton proposals submitted to annual XMM-Newton Call for Proposals with proposals due in October each year. The list of accepted proposals for cycle-22 is available on the XMM-Newton OTAC results website.
  • up to 500 ks of NuSTAR observing time for joint NuSTAR / Chandra observing projects submitted to the Chandra  Call for Proposals. Note that an additional 500 ks may also be allocated for Chandra V/LP programs. See CXC website for cycle-24 peer review recommended programs. The annual due date for Chandra proposals is usually in March.
  • up to 100 ks of NuSTAR observing time for joint NuSTAR / INTEGRAL observing proposals submitted to the INTEGRAL cycle-20 announcement of opportunity .The deadline for INTEGRAL AO-20 proposals is expected in April each year. A list of approved programmes for cycle-19 can be found on the INTEGRAL website.
  • up to 300 ks of NuSTAR observing time for joint NuSTAR / Swift proposals is expected to be available in Swift cycle-20, with proposals due in September 2023. A list of proposals selected for cycle-19 is available on the Swift website.
    • Note that 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).
  • up to 400 ks of NuSTAR observing time for joint NuSTAR / NICER proposals is expected to be available in NICER cycle-6, with proposals due in September, 2023. The list of accepted proposals for cycle-5 is available on the NICER GO website.
For the most complete list of planned and observed targets, as well as any ToOs that may be triggered before the beginning of cycle 6 observations on June 1st 2020, please refer to the NuSTAR  Master Catalog at the HEASARC, which may be queried using either Browse or Xamin. The full list of approved NuSTAR  ToO programs is available on the NuSTAR  SOC website.
The remaining 30% of the observing time will be allocated through the NuSTAR  project as follows:
  • NuSTAR  legacy survey observations (~ 3% of the total observing time)
  • NuSTAR  PI discretionary time, including unanticipated ToO observations open to the scientific community (~ 17%)
  • 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.