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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"

14951 results found.

  1. GRB 191024A: Swift detection of a burst
  2. GRB 191023A: Fermi GBM Final Real-time Localization
  3. GRB 191019B: AstroSat CZTI detection
  4. GRB 191022B: Fermi GBM Final Real-time Localization
  5. GRB 191022A: Fermi GBM Final Real-time Localization
  6. Swift GRB191020.89: Global MASTER-Net OT detection
  7. GRB 191019A: Swift/UVOT Detection
  8. HAWC-191019A: No Neutrino Counterpart detected with ANTARES
  9. Swift GRB191020.81: Global MASTER-Net OT detection
  10. GRB 191019B: Fermi GBM Final Real-time Localization
  11. GRB 191019A: NOT optical observations
  12. GRB 191019A: Swift detection of a burst
  13. GRB 191016A: Swift-XRT afterglow detection
  14. GRB 191016A: Swift/UVOT Detection
  15. GRB 191017C: Fermi GBM Final Real-time Localization
  16. GRB 191017B: Swift detection of a burst
  17. GRB 191017A: Fermi GBM Final Localization
  18. GRB 191016A: AZT-20 (Assy observatory) optical photometry
  19. GRB 191016A: early time BOOTES Network and follow-up 1.5m OSN optical observations
  20. GRB 191016A: Optical limit by Ondrejov D50
  21. GRB 191016A: COATLI Optical Observations and Detection of the Afterglow
  22. GRB 191016A: Swift detection of a burst
  23. GRB 191009A: AstroSat CZTI detection
  24. GRB 191011A: Swift/UVOT Detection
  25. GRB 19011A: Optical Afterglow Detection with LCO
  26. GRB 191009A: Insight-HXMT/HE detection
  27. GRB 191011A: GROND Detection of the Optical/NIR afterglow
  28. GRB 191011A: VLT X-shooter redshift from RRM Observations
  29. Swift GRB191011.19: Global MASTER-Net OT detection
  30. GRB 191011A: Swift detection of a burst with an optical counterpart
  31. GRB 191011A: Fermi GBM Final Real-time Localization
  32. GRB 191009A: Fermi GBM Final Real-time Localization
  33. TESS Detection of the Optical Emission from the Possible Untriggered GRB Associated with ZTF19abvizsw
  34. GRB 191004A: CALET Gamma-Ray Burst Monitor detection
  35. GRB 191008A: Fermi GBM Final Real-time Localization
  36. GRB 191004B: Swift/UVOT Detection
  37. Konus-Wind observation of GRB 191004B
  38. Konus-Wind observation of GRB 191004A
  39. GRB 191004A: Swift/UVOT Detection
  40. GRB 191004A: Optical Detection with LCO
  41. GRB 190928A: AstroSat CZTI detection
  42. GRB 191004B: GROND Detection of the Optical/NIR Afterglow
  43. GRB 191004B: Optical Afterglow Detection with LCO
  44. Swift GRB191004.9: Global MASTER-Net OT detection
  45. GRB 191004B: Swift detection of a burst with an optical counterpart
  46. FACT follow-up of IceCube-191001A
  47. GRB 191004A: Swift detection of a burst with an optical detection
  48. Swift GRB191004.75: Global MASTER-Net OT detection
  49. LIGO/Virgo S190930t: AT2019rpn, AT2019rpj CrAO continued optical photometry
  50. GRB 190926A: Upper limit from CAHA 2.2m observation
  51. IceCube-191001A: HAWC follow-up
  52. GRB 190919A: AstroSat CZTI detection
  53. LIGO/Virgo S190930t: Upper limits from Insight-HXMT/HE observations
  54. LIGO/Virgo S190930s: Upper limits from Insight-HXMT/HE observations
  55. IPN triangulation of GRB 191001A
  56. GRB 191001A: KAIT Optical Upper Limit
  57. GRB 191001A: RATIR Optical and NIR Observations
  58. IceCube-191001A - IceCube observation of a high-energy neutrino candidate event
  59. LIGO/Virgo S190930t: Upper limits on the two of the ZTF/GROWTH candidates
  60. LIGO/Virgo S190923y: optical spectrum of MASTER detected transient
  61. GRB 191001B: Swift detection of a burst
  62. LIGO/Virgo S190930t: Transient found in Swift/UVOT counterpart search
  63. LIGO/Virgo S190930t and S190930s: MASTER PSN in unknown disk galaxy
  64. LIGO/Virgo S190930t: Candidates from the Zwicky Transient Facility
  65. LIGO/Virgo S190930t and S190930s: MASTER optical observation and optical transient
  66. GRB 191001A: Fermi GBM Final Real-time Localization
  67. LIGO/Virgo S190930t: Upper limits from Fermi-GBM Observations
  68. LIGO/Virgo S190930s: Upper limits from Fermi-GBM Observations
  69. LIGO/Virgo S190930t: No counterpart candidates in HAWC observations
  70. GRB 190928A: Insight-HXMT/HE detection
  71. Konus-Wind observation of GRB 190928A
  72. GRB 190928A: MASTER optical observations
  73. GRB 190930A: Fermi GBM Final Real-time Localization
  74. GRB 190928A: CALET Gamma-Ray Burst Monitor detection
  75. GRB 190926A: AbAO upper optical limit
  76. GRB 190928A: AGILE/MCAL detection of a burst
  77. GRB 190926A: Upper Limit from OSN T150 Observation
  78. LIGO/Virgo S190923y: MASTER OT outburst detection inside NSBH merger error-box
  79. GRB 190926A: Swift detection of a burst
  80. LIGO/Virgo S190924h: Upper limits from Fermi-GBM Observations
  81. IceCube-190922B - HAWC follow-up
  82. LIGO/Virgo S190923y: Upper limits from Fermi-GBM Observations
  83. LIGO/Virgo S190814bv: Chandra X-ray non-detection of ASKAP J005547-270433 / AT2019osy
  84. GRB 190923A: Fermi GBM Final Real-time Localization
  85. LIGO/Virgo S190923y: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  86. LIGO/Virgo S190923y: No counterpart candidates in HAWC observations
  87. IceCube-190922B - IceCube observation of a high-energy neutrino candidate event
  88. IceCube-190922A - IceCube observation of a high-energy neutrino candidate event
  89. GRB 190921A: Fermi GBM Final Real-time Localization
  90. GRB 190919B: LCO Optical Afterglow Detection
  91. GRB 190919B: FRAM-Auger optical detection
  92. GRB 190919B: MASTER OT early detection at GROND position
  93. GRB 190919B: GROND detection of the NIR afterglow
  94. GRB 190919A: Fermi GBM Final Real-time Localization
  95. HAWC-190916A: Upper limits from Insight-HXMT/HE observations
  96. GRB 190828B: AstroSat CZTI detection
  97. LIGO/Virgo S190915ak: Upper limits from Fermi-GBM Observations
  98. GRB 190916A: Fermi GBM Final Real-time Localization
  99. GRB 190915A: Insight-HXMT/HE detection
  100. GRB 190915A: Fermi GBM Final Real-time Localization

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