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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"

27298 results found.

  1. GRB 231111A: Swift-XRT refined Analysis
  2. GRB 231111A: GECAM-C detection of a long burst (correction)
  3. GRB 231110A: GECAM-B detection (correction)
  4. GRB 231111A: GECAM-C detection of a long burst
  5. GRB 231110A: GECAM detection
  6. GRB 231110A: GOTO optical upper limits
  7. GRB231111A: GIT confirmation of the optical afterglow
  8. GRB 231111A: MASTER OT earlier detection
  9. GRB 231111A: Nanshan/HMT optical observations
  10. GRB 231111A: Swift detection of a burst with an optical counterpart
  11. Swift GRB231111.60: Global MASTER-Net observations report
  12. Swift GRB231110.89: Global MASTER-Net observations report
  13. GRB 231110A: Swift detection of a burst
  14. GRB 231109A: Fermi GBM Final Localization
  15. Fermi trigger No 721204446: Global MASTER-Net observations report
  16. Fermi GRB 231108A: Global MASTER-Net observations report
  17. GRB 231108A: Fermi GBM Final Real-time Localization
  18. GRB 231106A: CALET Gamma-Ray Burst Monitor detection
  19. GRB 231104A: Swift-BAT refined analysis
  20. Fermi trigger No 721006392: Global MASTER-Net observations report
  21. Fermi Gamma-ray Burst Monitor trigger 231107654 / 721064512 is not a GRB
  22. GRB 231104A: FRAM-ORM optical limit
  23. LIGO/Virgo/KAGRA S231102w: Upper limits from Swift/BAT-GUANO
  24. Fermi GRB 231106A: Global MASTER-Net observations report
  25. GRB 231104A: Wendelstein Optical/Infrared Observations
  26. GRB 231104A: NuSTAR Observation of the prompt emission
  27. GRB 231106A: Fermi GBM Final Real-time Localization
  28. LIGO/Virgo/KAGRA S231106y: one counterpart neutrino candidate from IceCube neutrino searches
  29. GRB 231104A: NOT upper limit
  30. GRB 231104A: Fermi GBM Observation
  31. GRB 231104B: Fermi GBM Final Real-time Localization
  32. Fermi GRB 231103A: Global MASTER-Net observations report
  33. GRB 231104A: AKO Upper Limit
  34. GRB 231104A: Swift-XRT refined Analysis
  35. GRB 231104A: Fermi-LAT detection
  36. GRB 231104A: Swift/UVOT Upper Limits
  37. GRB231104A: LCOGT Optical Upper Limits
  38. GRB 231104A: Swift detection of a bright burst
  39. GRB 231104A: Fermi GBM Final Real-time Localization
  40. Swift GRB231104.07: Global MASTER-Net observations report
  41. IceCube Alert 231103.39: Global MASTER-Net observations report
  42. GRB 231103A: Fermi GBM Final Real-time Localization
  43. LIGO/Virgo/KAGRA S231102i: Global MASTER-Net observations report
  44. Fermi trigger No 720498201: Global MASTER-Net observations report
  45. GRB 231101A: Fermi GBM Final Real-time Localization
  46. GRB 231028B: VZLUSAT-2 detection
  47. Fermi trigger No 720415645: Global MASTER-Net observations report
  48. GRB 231030B: Fermi GBM Detection
  49. Fermi GRB 231030B: Global MASTER-Net observations report
  50. IPN triangulation of GRB 231020A
  51. GRB 231030B: BALROG localization (Fermi Trigger 720388704 / GRB 231030832)
  52. GRB 231030B: Fermi GBM Final Real-time Localization
  53. GRB 231028A: Swift-BAT refined analysis
  54. LIGO/Virgo/KAGRA S231029y: Upper limits from Swift/BAT-GUANO
  55. LIGO/Virgo/KAGRA S231030av: Retraction of GW compact binary merger candidate
  56. GRB 231024A: AKO Optical Counterpart Candidate
  57. GRB 231028A: CALET Gamma-Ray Burst Monitor detection
  58. Fermi GRB 231030A: Global MASTER-Net observations report
  59. GRB 231030A: Fermi GBM Final Real-time Localization
  60. LIGO/Virgo/KAGRA S231029y: One counterpart neutrino candidate from IceCube neutrino searches
  61. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  62. GRID detection of GRB 231020A
  63. LIGO/Virgo/KAGRA S231029k: Global MASTER-Net observations report
  64. GRB 231028A: Fermi GBM Detection
  65. Fermi trigger No 720224759: Global MASTER-Net observations report
  66. Swift GRB 231028A: Global MASTER-Net observations report
  67. GRB 231028A: Swift detection of a burst
  68. GRB 231028A: Fermi GBM Final Real-time Localization
  69. IceCube Alert 231027.18: Global MASTER-Net observations report
  70. LIGO/Virgo/KAGRA S231025t: Global MASTER-Net observations report
  71. LIGO/Virgo/KAGRA S231025a: Global MASTER-Net observations report
  72. GRB 231025A: Fermi GBM Observation
  73. GRB 231024A: Fermi GBM Observation
  74. GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
  75. GRB 231025A: Fermi GBM Final Localization
  76. GRB 231024A: GOTO optical counterpart candidate
  77. LIGO/Virgo/KAGRA S231025a: two counterpart neutrino candidates from IceCube neutrino searches
  78. GRB 231024A: Fermi GBM Final Localization
  79. Fermi trigger No 719846439: Global MASTER-Net observations report
  80. GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  81. LIGO/Virgo/KAGRA S231020bw: Upper limits from Swift/BAT-GUANO
  82. LIGO/Virgo/KAGRA S231021az: Coverage and upper limits from MAXI/GSC observations
  83. GRB 231020A: Fermi GBM Detection
  84. GRID detection of GRB 231004A
  85. GRB 231020B: BALROG localization (Fermi Trigger 719530557 / GRB 231020900)
  86. GRB 231020B: Fermi GBM Final Real-time Localization
  87. GRB 231020A: BALROG localization (Fermi Trigger / GRB 231020790)
  88. LIGO/Virgo/KAGRA S231020ba: Upper limits from Fermi-GBM Observations
  89. GRB 231015A: NuSTAR Detection of Prompt Emission
  90. Fermi GRB 231020A: Global MASTER-Net observations report
  91. GRB 231020A: Fermi GBM Final Real-time Localization
  92. GRB 231012A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
  93. LIGO/Virgo/KAGRA S231020ba: Coverage and upper limits from MAXI/GSC observations
  94. GRB 231017A: 1.3m DFOT Optical upper limit
  95. IceCube-231004A: Upper limits from Fermi-GBM Observations
  96. GRB 231018A: CALET Gamma-Ray Burst Monitor detection
  97. Fermi GRB 231019A: Global MASTER-Net observations report
  98. IPN triangulation of GRB 231018A
  99. GRB 231017A: Swift/UVOT Upper Limit
  100. GRB 231019A: Fermi GBM Final Real-time Localization

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