NuSTAR ToO targets approved within the NuSTAR, Chandra, XMM-Newton, Swift, NICER, and INTEGRAL General Observer programs

    NuSTAR Target of Opportunity (ToO) observations may be proposed for in the NuSTAR, Chandra, XMM-Newton, Neil Gehrels Swift Observatory, NICER mission, and INTEGRAL General Observer (GO) programs.

    Last update: 2023-01-14

      Proposal title and abstracts are available here, or click on the Proposal number in the table below. Note that NuSTAR ToO and DDT observations may be requested at any time through the ToO/DDT observation request form which provides a list of currently active unanticipated ToO/DDT targets.

      Proposals will be marked with an orange background when they are triggered and a green background when they are completed. Targets that have yet to be identified have blank J2000 coordinates.

Coordinated with XMM-Newton
Coordinated with IXPE
NuSTAR GO ToO programs
ObsIDTarget Name
J2000 RA (deg)
J2000 Dec (deg)
Exposure (ks)
07221Somalwar80702614TC0052307.69720944.2252688663 x 20Coordinated with Swift
Triggered 2022-03-08
08003Mori80802325GC X-ray Transient 2x20
08033Ballhausen80801326RX J0440.9+443170.24720744.53034950Triggered 2023-01-02
08041Jiang80801327Black hole transient 30
08079Coughenour80801328AT2019wey68.846980 55.376190 50
Coordinated with NICER
Triggered 2022-12-12
08107Krucker80802200The SUN 2x25
08110Paliya80801629Swift-BAT blazar 1 20
08110Paliya80801630Swift-BAT blazar 2 20
08115Miller80801631Bright TDE 50
08121Mondal80801332FXT/VFXT 30
08125Jaisawal808013334U 1820-30275.91904-30.3612845
Coordinated with NICER
08131Krumpe80801634AGN flux drop 100
08136Sokolovsky80801335New Nova 60
08166Feng80802636B3 2247+381342.524 38.410 2x40Triggered 2022-09-24
Coordinated with Swift & VERITAS
08167Krumpe80801637AGN-ignition 1 50
08167Krumpe80801638AGN ignition 2 50
08171McBride80801639TXS 2320+343350.683393 34.603854 40Triggered 2022-12-26
08171McBride80801640ICECUBE 2 40
08201Shaw80801341GX 339-4255.70575-48.7897820Triggered 2022-09-06
Coordinated with JWST
08201Shaw80801342Generic Black Hole LMXB 20Coordinated with JWST
08211Arbet-Engels80801643BL Lac type transient 40
08219Draghis80802344XTE J2012+381303.1573 38.1837 2x30Triggered 2022-12-26
08219Draghis80802345Black hole transient 2 2x30
08219Draghis80802346Black hole transient 3 2x30
08226Pike80801347MAXI J0655-013103.7930 -1.5310 40Triggered 2022-06-19
08226Pike80802348Unknown MAXI source 2 2x20
08226Pike80802349Unknown MAXI source 3 2x20
08227Arbet-Engels808016501ES 2344+514 low state356.7701751.7049720triggered 2022-07-28 Coordinated with XMM and MAGIC
08227Arbet-Engels808016511ES 2344+514 high state356.7701751.7049720
08233Lawther80802652Mrk 59033.63992-0.7667520+20+60+50
Coordinated with XMM-Newton & NICER
08234Haemmerich80801653Flaring Blazar 50
Coordinated with Gehrels-Swift
08236Bonnoli80801654New VHE FSRQ 40
08246Jaodand80802755Binary NS merger afterglow 100+75+75
Joint NuSTAR/Chandra GO ToO programs
23400247Neilsen80802303Black Hole Transient 4 x 25
23500541Chornock80802504SN2012ap75.057167-3.3475602 x 50Triggered 2022-12-28
24400072Mori80902301GC transient 2x20
24400242Neilsen80902302Black Hole transient 4x25
24500203Brethauer80902503Interacting SN 2x50
24500280Matthews80902404AT2022tsd50.045282 8.748878 2x25,2x40Triggered 2022-10-07
Joint NuSTAR/XMM-Newton GO ToO programs
088008Norbert Schartel80701608RX J0128.1-184822.0280-18.80862550
Triggered 2022-11-29
Coordinated with SALT or HET
088008Norbert Schartel80701609AGN outburst 250
Coordinated with SALT or HET
088054Pierre-Olivier Petrucci80702310BH LMXB10x20
088218Nanda Rea80702311SGR J1935+2154293.732021.89672050+40+80Triggered 2022-10-17
088470Alessandro Papitto80701312SAX J1808.4-3658272.114750-36.978970120Triggered 2022-08-20
Coordinated with IXPE
090022Norbert Schartel80801601AGN Minimum 180Coordinated with HST
80801602AGN Minimum 280
090023Norbert Schartel80801603PG 0043+03911.4467924.17315660Coordinated with HST and HET/SALT
Triggered 2022-06-16
090067Adam Ingram80802309GRS 1915+105288.79812510.9457783x30Coordinated with IXPE
090245Missagh Mehdipour80801604AGN obscuration30Coordinated with HST
090251Daniel Stern80860601eROSITA-fader120
090284Javier Garcia80801305BH transient40
090332David Matthews80802406FBOT2x25+2x40
090357Sergio Campana80801507GW counterpart160Coordinated with HST and NRAO
80801508GW counterpart260
092118Raffaella Margutti80902505SNinteracting 2x50Cycle-22 begins on 2023-05-01
092270Elias Kammoun80902606SMSS J114447.77-430859.3176.199-43.149842x80Cycle-22 begins on 2023-05-01
092317Alessandro Papitto80901307Accreting ms pulsar 120Coordinated with IXPE
Cycle-22 begins on 2023-05-01
092331Missagh Mehdipour 80901608NGC 3516 166.69776372.5686960Coordinated with HST
Cycle-22 begins on 2023-05-01
092346Arianna Miraval Zanon80901309Transitional ms pulsar 60Coordinated with VLA
Cycle-22 begins on 2023-05-01
092410Erin Kara80902610Mrk 817219.0920085858.794276360Coordinated with HST
Cycle-22 begins on 2023-05-01
Joint NuSTAR/INTEGRAL GO ToO programs
1840002Thomas Siegert80701501NS merger100
1840005Zhaosheng Li80701302ms pulsar30Also coordinated with XMM-Newton, NICER, and HXMT
1840021Ingo Kreykenbohm80701303Accreting X-ray pulsar40
1940020Ingo Kreykenbohm80801301Transient accreting pulsar40
1940025Thomas Siegert80801502GW Neutron star merger100
Joint NuSTAR/Swift GO ToO programs
1821098Kirill Sokolovsky80801310New Nova40
1821161Maria-Carla Nicotra80801311FRB120
1821161Maria-Carla Nicotra80801312FRB220
Joint NuSTAR/NICER GO ToO programs
04163Jeroen Homan807023184U 1820-30 275.91904-30.3612783x20Triggered 2021-06-12
05001Fiamma Capitanio808023134U1630-47248.5067083-47.39302x30 + 20Triggered 2022-08-22
Coordinated with IXPE
05001Fiamma Capitanio80802314Transient XRB-22x30 + 20
Coordinated with IXPE
05001Fiamma Capitanio80802315Transient XRB-32x30 + 20
Coordinated with IXPE
05065Riley Connors80802316Transient BH Binary4x20
05076Teruaki Enoto80802317SGR J1935+2154293.732021.8967250+50Triggered 2022-10-12
Coordinated with DSN
05079Alice Borghese80801318Magnetar Outburst-120
05079Alice Borghese80801319Magnetar Outburst-220
05099Federico Garcia80802320GX 339-4255.705754-48.789753x20Triggered 2022-08-30
05106Filippo D'Ammando80801605Blazar40
05118Jingyi Wang80802321IGR J17091-3624257.2833-36.40673x20Triggered 2022-04-12
05131Joseph Neilsen80801322GRS 1915+105288.79816710.94580625
05140Guglielmo Mastroserio80801323BH transient50
05172Javier Garcia80801324IGR J17091-3624257.2833-36.4067100Triggered 2022-08-17
06039Teruaki Enoto 80902311Magnetar Outburst 20+30+50NICER cycle-5 begins on 2023-03-01
Coordinated with DSN
06057Fiamma Capitanio 80902312Transient BH XRB 30+30+20NICER cycle-5 begins on 2023-03-01
Coordinated with IXPE
06078Yuhan Yao 80901615Tidal Disruption Event50 NICER cycle-5 begins on 2023-03-01
06113Adam Ingram 80902316GRS 1915+105 288.79816710.9458063x20 NICER cycle-5 begins on 2023-03-01
06141Jingyi Wang 80902317Transient BH Binary3x20 NICER cycle-5 begins on 2023-03-01
06143James Steiner 80902318Cygnus X-1 299.59033335.2016113x20 NICER cycle-5 begins on 2023-03-01
Coordinated with IXPE
06197Joseph Neilsen 80901320GRS 1915+105 288.79816710.94580625 NICER cycle-5 begins on 2023-03-01
06203Paul Draghis 80901321BH transient #1 30 NICER cycle-5 begins on 2023-03-01
80901321BH transient #2 30

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