NuSTAR Target of Opportunity (ToO) or Directors Discretionary Time (DDT) observation request

NuSTAR observatory operations will continue during the COVID-19 pandemic including all approved ToO programs.

NuSTAR ToO and DDT observation requests will in general not be considered for events or sources that could have been predicted and proposed for in General Observer (GO) programs. This restriction is being adopted as a result of guidance from NASA's 2019 Senior Review.

In particular, requests for observations of the following types of sources and events require special justification describing why the requested observation type could not have been proposed as a GO target:

Known or candidate black hole systems

Known or candidate pulsar or magnetar systems

Candidate counterparts of gravitational wave or astrophysical neutrino detections

Nova or Supernova events

Luminosity variations from known or candidate AGN (including blazars and Tidal Disruption Events)

Observations of the Sun or other Solar system objects

Observations of events with specific time constraints

Observations coordinated with other observatories that could have been proposed for to joint GO programs

As a specific example, binary systems where periastron intervals are known can be proposed to the GO program, with observations triggered from monitoring of activity by other observatories. Observations that are simultaneous with ground or space based activities can also be proposed to the GO program, even if the exact dates for the coordinated observations are not known at the time of the proposal.

We encourage the community to propose to the various peer reviewed GO programs for NuSTAR ToO observations. Observations of all selected GO ToO observations automatically have the highest priority for scheduling.

Active ToO/DDT observations

GRS 1915+105 25 ks coordianted with Chandra and NICER observations PI Neilsen

V4641 Sgr 5x20 ks coordinated with 5x10 ks NICER observations for joint NICER / NuSTAR GO program 7113 PI Neilsen

GX 339-4 3x20 ks coordinated with NICER for NICER GO program 4152 PI Sridhar

4U 1820+30 3 x 20 ks coordinated with NICER for the NICER GO ToO program 4163 PI Homan

Last updated: 2021-10-14 1700 UT

Active ToO/DDT observations
GRS 1915+105	25 ks coordianted with Chandra and NICER observations	PI Neilsen
V4641 Sgr	5x20 ks coordinated with 5x10 ks NICER observations for joint NICER / NuSTAR GO program 7113	PI Neilsen
GX 339-4	3x20 ks coordinated with NICER for NICER GO program 4152	PI Sridhar
4U 1820+30	3 x 20 ks coordinated with NICER for the NICER GO ToO program 4163	PI Homan

Please review the NuSTAR schedules for details of upcoming observations and the table of approved ToO programs from the NuSTAR GO program and joint GO programs with Chandra, XMM-Newton, INTEGRAL, and the Neil Gehrels Swift Observatory.

Principal requester
Name:
Institute:
Primary Email address: (additional email address can be supplied in Remarks section below)
Best way to reach me:
24 hr Contact info:	Phone numbers etc
Scientific Justification
Object type:
Triggering an approved GO program:	If yes, then give mission and GO proposal number:
Scientific Justification:	Please limit to 2000 characters.
Relevant URLs	one per line
Justification for this particular target:	Please limit to 1000 characters.
Likelihood of detection, duration, and recurrence of transient behavior:	Please limit to 400 characters.
Response time requested:	Examples: < 24 hours , < 48 hours , within 1 week , at directors discretion (DDT) Note that the majority of approved ToOs have response times within 1 week
Justification for requested response time:	Please limit to 1000 characters.
Target details
Target Name
RA (J2000 decimal degrees from 0.0 to 360.0)
Dec (J2000 decimal degrees from -90.0 to 90.0)	from until Date/time format options are described here. Default is UTC, unless you specify another time zone.
Observing time (kiloseconds)
Justification for observing time (Give details of any source modeling, particularly for exposure time requests above 50 ks)	Please limit to 1000 characters.
Expected NuSTAR count rate (predicted instrument count rate for both modules using 50% PSF extraction with no dead time)	HEASARC WebPIMMS (set "Into:" field to 'NUSTAR') here.
Maximum expected NuSTAR count rate (in case of flaring, bursts, etc)
Approximate expected spectrum
Source morphology
Coordination with other observatories?:	Please limit to 1000 characters.
Remarks	Please limit to 1000 characters.
Clicking the Submit button sends emails and text messages to the NuSTAR operations team. A confirmation email will be sent to the 'Email:' field at the time of submission. The request will be reviewed by the NuSTAR PI and the operations team and you will be contacted with a decision to approve or decline the request. NuSTAR data associated with ToO or DDT requests submitted outside of approved GO programs will have no exclusive use period and, when completed, will be available via the public NuSTAR archive. See heasarc.gsfc.nasa.gov/docs/nustar/nustar_archive.html for more information. A minimal set of data products for ToO/DDT observations performed within the last 14 days is also available as each observation progresses via the NuSTAR quicklook products webpage. Please carefully read the caveats on the use of this data detailed on the quicklook webpage. Please contact nustar-help at srl.caltech.edu if you have any questions.