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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"

27301 results found.

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

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