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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

14950 results found.

  1. GRB 191023A: Fermi GBM Final Real-time Localization
  2. GRB 191019B: AstroSat CZTI detection
  3. GRB 191022B: Fermi GBM Final Real-time Localization
  4. GRB 191022A: Fermi GBM Final Real-time Localization
  5. Swift GRB191020.89: Global MASTER-Net OT detection
  6. GRB 191019A: Swift/UVOT Detection
  7. HAWC-191019A: No Neutrino Counterpart detected with ANTARES
  8. Swift GRB191020.81: Global MASTER-Net OT detection
  9. GRB 191019B: Fermi GBM Final Real-time Localization
  10. GRB 191019A: NOT optical observations
  11. GRB 191019A: Swift detection of a burst
  12. GRB 191016A: Swift-XRT afterglow detection
  13. GRB 191016A: Swift/UVOT Detection
  14. GRB 191017C: Fermi GBM Final Real-time Localization
  15. GRB 191017B: Swift detection of a burst
  16. GRB 191017A: Fermi GBM Final Localization
  17. GRB 191016A: AZT-20 (Assy observatory) optical photometry
  18. GRB 191016A: early time BOOTES Network and follow-up 1.5m OSN optical observations
  19. GRB 191016A: Optical limit by Ondrejov D50
  20. GRB 191016A: COATLI Optical Observations and Detection of the Afterglow
  21. GRB 191016A: Swift detection of a burst
  22. GRB 191009A: AstroSat CZTI detection
  23. GRB 191011A: Swift/UVOT Detection
  24. GRB 19011A: Optical Afterglow Detection with LCO
  25. GRB 191009A: Insight-HXMT/HE detection
  26. GRB 191011A: GROND Detection of the Optical/NIR afterglow
  27. GRB 191011A: VLT X-shooter redshift from RRM Observations
  28. Swift GRB191011.19: Global MASTER-Net OT detection
  29. GRB 191011A: Swift detection of a burst with an optical counterpart
  30. GRB 191011A: Fermi GBM Final Real-time Localization
  31. GRB 191009A: Fermi GBM Final Real-time Localization
  32. TESS Detection of the Optical Emission from the Possible Untriggered GRB Associated with ZTF19abvizsw
  33. GRB 191004A: CALET Gamma-Ray Burst Monitor detection
  34. GRB 191008A: Fermi GBM Final Real-time Localization
  35. GRB 191004B: Swift/UVOT Detection
  36. Konus-Wind observation of GRB 191004B
  37. Konus-Wind observation of GRB 191004A
  38. GRB 191004A: Swift/UVOT Detection
  39. GRB 191004A: Optical Detection with LCO
  40. GRB 190928A: AstroSat CZTI detection
  41. GRB 191004B: GROND Detection of the Optical/NIR Afterglow
  42. GRB 191004B: Optical Afterglow Detection with LCO
  43. Swift GRB191004.9: Global MASTER-Net OT detection
  44. GRB 191004B: Swift detection of a burst with an optical counterpart
  45. FACT follow-up of IceCube-191001A
  46. GRB 191004A: Swift detection of a burst with an optical detection
  47. Swift GRB191004.75: Global MASTER-Net OT detection
  48. LIGO/Virgo S190930t: AT2019rpn, AT2019rpj CrAO continued optical photometry
  49. GRB 190926A: Upper limit from CAHA 2.2m observation
  50. IceCube-191001A: HAWC follow-up
  51. GRB 190919A: AstroSat CZTI detection
  52. LIGO/Virgo S190930t: Upper limits from Insight-HXMT/HE observations
  53. LIGO/Virgo S190930s: Upper limits from Insight-HXMT/HE observations
  54. IPN triangulation of GRB 191001A
  55. GRB 191001A: KAIT Optical Upper Limit
  56. GRB 191001A: RATIR Optical and NIR Observations
  57. IceCube-191001A - IceCube observation of a high-energy neutrino candidate event
  58. LIGO/Virgo S190930t: Upper limits on the two of the ZTF/GROWTH candidates
  59. LIGO/Virgo S190923y: optical spectrum of MASTER detected transient
  60. GRB 191001B: Swift detection of a burst
  61. LIGO/Virgo S190930t: Transient found in Swift/UVOT counterpart search
  62. LIGO/Virgo S190930t and S190930s: MASTER PSN in unknown disk galaxy
  63. LIGO/Virgo S190930t: Candidates from the Zwicky Transient Facility
  64. LIGO/Virgo S190930t and S190930s: MASTER optical observation and optical transient
  65. GRB 191001A: Fermi GBM Final Real-time Localization
  66. LIGO/Virgo S190930t: Upper limits from Fermi-GBM Observations
  67. LIGO/Virgo S190930s: Upper limits from Fermi-GBM Observations
  68. LIGO/Virgo S190930t: No counterpart candidates in HAWC observations
  69. GRB 190928A: Insight-HXMT/HE detection
  70. Konus-Wind observation of GRB 190928A
  71. GRB 190928A: MASTER optical observations
  72. GRB 190930A: Fermi GBM Final Real-time Localization
  73. GRB 190928A: CALET Gamma-Ray Burst Monitor detection
  74. GRB 190926A: AbAO upper optical limit
  75. GRB 190928A: AGILE/MCAL detection of a burst
  76. GRB 190926A: Upper Limit from OSN T150 Observation
  77. LIGO/Virgo S190923y: MASTER OT outburst detection inside NSBH merger error-box
  78. GRB 190926A: Swift detection of a burst
  79. LIGO/Virgo S190924h: Upper limits from Fermi-GBM Observations
  80. IceCube-190922B - HAWC follow-up
  81. LIGO/Virgo S190923y: Upper limits from Fermi-GBM Observations
  82. LIGO/Virgo S190814bv: Chandra X-ray non-detection of ASKAP J005547-270433 / AT2019osy
  83. GRB 190923A: Fermi GBM Final Real-time Localization
  84. LIGO/Virgo S190923y: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  85. LIGO/Virgo S190923y: No counterpart candidates in HAWC observations
  86. IceCube-190922B - IceCube observation of a high-energy neutrino candidate event
  87. IceCube-190922A - IceCube observation of a high-energy neutrino candidate event
  88. GRB 190921A: Fermi GBM Final Real-time Localization
  89. GRB 190919B: LCO Optical Afterglow Detection
  90. GRB 190919B: FRAM-Auger optical detection
  91. GRB 190919B: MASTER OT early detection at GROND position
  92. GRB 190919B: GROND detection of the NIR afterglow
  93. GRB 190919A: Fermi GBM Final Real-time Localization
  94. HAWC-190916A: Upper limits from Insight-HXMT/HE observations
  95. GRB 190828B: AstroSat CZTI detection
  96. LIGO/Virgo S190915ak: Upper limits from Fermi-GBM Observations
  97. GRB 190916A: Fermi GBM Final Real-time Localization
  98. GRB 190915A: Insight-HXMT/HE detection
  99. GRB 190915A: Fermi GBM Final Real-time Localization
  100. LIGO/Virgo S190814bv: No counterpart candidate after completion of GRAWITA VST-ESO PARANAL transient survey.

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