NuSTAR Bringing the High Energy Universe into Focus


NuSTAR Users' Committee

The NuSTAR Users' Committee (NUC) is a group of 5-10 astrophysicists representing a wide range of community interests who provide the NuSTAR project with broad-based input about the needs and priorities of the NuSTAR user community during the extended operational mission phase.

The NUC is the primary interface between the NuSTAR community and the NuSTAR project and NASA headquarters and assists the NuSTAR Principal Investigator and Project Scientist during NuSTAR's operational phase and in preparation for future Senior Reviews.

The NUC nominally meets twice a year. NUC meetings are a forum for the NuSTAR Guest Investigator (GI) community to provide feedback to ensure the interests of the community are served by the NuSTAR Science Operations Center (NSOC) in planning for and executing NuSTAR operations.

Key areas that the NUC examines are:

If you have a matter you would like raised at a NUC meeting,  please  email:  

nuc-chair _at_

NUC Documents


Minutes and presentations from NUC meetings and telecons

2018-04-19 2018-07-17 2018-08-18 2019-01-08 2019-09-27 2020-01-05
2020-08-19 2021-01-20 2021-12-14 2022-10-14 2023-06-09 2024-04-23



April 19th, 2018

  • The first NUC meeting was held as a telecon (PDF minutes).
  • Summary
    1. Not a lot of enthusiasm for changing the general GO data right policy.
    2. Recommendation is to write a specific policy for DDT data rights and announce it widley to NuSTAR users.
    3. The NUC is happy to see progress on cross-calibration.
    4. The COSPAR is looking like a good option for the face-to-face meeting of the NUC.

July 17th, 2018

  • The NUC met in the Cahill center for Astronomy and Astrophysics on the Caltech campus (PDF minutes).
  • Summary
    1. Data from DDT observations: The project has made a change to respond to the NUC's recommendation, and it seems likely that it will address the issue. See SOC Quicklook webpage.
    2. Senior review proposal planning: NUC members will indicate how they would like to be involved in the senior review proposal process. The SOC and GOF will compile data on whether there is pressure for large proposals. A follow-up telecon will be organized to discuss time allocation (Legacy, GO, GO-large, ToO/DDT) for the senior review proposal and possible adjustments in time for GO cycle-5.
    3. Outreach: The project will send an email to PIs of GO proposals encouraging web or press releases and describing how the process works.
    4. Minumim exposure time: This should be discussed further on a follow-up telecon.
    5. nuskybgd: GOF will discuss how this software package (for producing simulated NuSTAR background) can be made useable by a larger number of NuSTAR observers.

August 18th, 2018

  • The NUC was held as a telecon (PDF minutes).
  • Summary
    1. Legacy time and Large proposals: The NUC recommends moving Legacy time to: Required Observations (these will be written into the Senior Review proposal and examples are given in the minutes); and a new category of Large GO proposals. Some current Legacy programs (such as the Swift/BAT AGN snapshots) should be continued, and these can either go into the Required Observations or be rebranded in some way. For AO-5, the NUC recommends that the uncertainty about the number of high-quality Large proposals be addressed by indicating a fairly large range of time that will be allocated. A suggestion would be a range of 1-2 Ms. If large proposals are required to be at least 400 ks, then this would still allow for 3-4 Large proposals to be accepted in AO-5. If the Large programs are successful, then the range can be reduced (1.5-2 Ms?) or eliminated (2 Ms?) in future AOs.
    2. DDT time: If the number of requests for DDT Target of Opportunity observations increases, then the NUC recommends that a Transient Advisory Committee is formed to assist with evaluating the DDT requests. The NUC also suggests that the project consider whether such a committee is needed sooner to estimate how many transients are likely to need NuSTAR observations.

January 8th, 2019

  • The NUC met in the exhibit hall at the 223rd meeting of the AAS in Seattle, WA (PDF minutes).
  • Summary
    1. Topics from the project side:
      • Discussions about NuSTAR GO cycle-5
      • Increasing number of ToO observations
      • NuSTAR science meeting.
    2. New or  outstanding items from the NUC:
      • Concern about GO proposals not approved because targets are in the NuSTAR legacy survey
      • Clarification about rules for ToOs on targets from multiple proposals (e.g. gravitational wave followup observations)
      • Calibration improvements for Swift and impact on cross-calibration with NuSTAR
      • Implementation of nuskybgd as an FTOOL or python script
      • Timing artifacts in NuSTAR power spectra
      • Stray light checks.
    3. 2019 Senior review proposal:
      • Draft comments from the NUC have been sent to the NuSTAR PI
        • Possibly adjust limit on ToO allocation
  • Actionable Items from the NUC have been sent to the NuSTAR PI (see PDF minutes).

September 27th, 2019

  • The NUC met via a telecon (PDF minutes).
  • Summary
    1. NuSTAR GO cycle-6 topics:
      • Implementation of dual-anonymous proposal review
      • Allowing multi-cycle proposals
      • Reducing minimum exposure time requirement for proposed observations
      • Direct funding of Co-I's for selected proposals
      • Page limit for large proposal category
  • Recommendations from the NUC have been sent to the NuSTAR PI and GOF (see PDF minutes).

January 5th, 2020

  • The NUC met at the AAS meeting in Honolulu, HI (PDF minutes).
  • Summary
    • Balancing selections in a dual-anonymous proposal review
    • NuSTAR conference in Sardinia, June 2020
    • Direct funding for NuSTAR GO proposal Co-I's
    • Rotation of NUC membership
    • Communication of actions taken in response to 2019 Senior Review report
    • NuSTAR calibration update

August 19th, 2020

  • The NUC met via a telecon (PDF minutes).
  • Summary
    • Outcomes of cycle 6 and discussion about cycle 7
    • Optimizing communication between the NuSTAR project and the astrophysics community
    • Calibration activities and discussion of priorities
    • Plan for rotating NUC membership

January 20th, 2021

  • The NUC met via a telecon (PDF minutes).
  • Summary
    • NuSTAR's policy on exclusive use periods

December 14th, 2021

  • The NUC met via a telecon (PDF minutes).
  • Summary
    • Mission update / status
    • Senior Review proposal discussion

October 14th, 2022

  • The NUC met via a telecon (PDF minutes).
  • Summary
    • Mission update / status
    • XRISM PV-phase support
    • NUC logistics and rotations
    • Inclusion plans in GO proposals
    • AOB

June 9th, 2023

  • The NUC met via a telecon (PDF minutes).
  • Summary
    • Mission update / status (2.9MB PDF file)
    • AO9 results, including XRISM PV coordination plans
    • cross calibration updates (esp. XMM)
    • NUC rotations & logistics
    • AOB

April 23rd, 2024

  • The NUC met via a telecon (PDF minutes).
  • Summary
    • Mission update / status (3.7MB PDF file)
    • AO10 results, including XRISM PV coordination status
    • AO exchanges of time with other missions 
    • Project response to previous NUC requests:  gain offset
    • Estimating NuSTAR gain with BAT AGN
    • Preparing for the 2025 Senior Review
    • AOB
    • NUC discussions - rotations & logistics

Current Users' Committee Members:



Daniel Wik  The University of Utah
              email:   nuc-chair _at_



Marco Ajello   Clemson University
Enrico Bozzo   University of Geneva
Joel Coley   Howard University
Stephanie LaMassa   Space Telescope Science Institute
Anne Lohfink   Montana State University
Raffaella Margutti   CIERA, Northwestern University
Andrea Marinucci   ASI - Agenzia Spaziale Italiana
Aarran Shaw   University of Nevada, Reno
Jack Steiner   MIT Kavli Institute


Ex-Officio Members

Fiona Harrison NuSTAR Principal Investigator
Daniel Stern NuSTAR Project Scientist
Hashima Hasan NASA HQ NuSTAR Program Scientist


The NUC consists of 5-10 members of the NuSTAR science community, who are chosen by the NuSTAR Principal Investigator, NASA HQ Program Scientist and the NUC Chair, in concurrence. The chair is appointed by the NuSTAR Principal Investigator in concurrence with the NASA HQ Program Scientist. The members represent a wide range of community interests and exhibit general knowledge of the NuSTAR mission to enable the NUC to provide the project with broad-based input about the needs and priorities of the NuSTAR user community during the NuSTAR extended operational mission phase.


Last updated: 2024-04-24