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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

11109 results found.

  1. GRB 240527B: Fermi-LAT detection
  2. Fermi GRB 240527B: Global MASTER-Net observations report
  3. GRB 240527B: Fermi GBM Final Localization
  4. GRB 240527B: BALROG localization (Fermi Trigger 738511436 / GRB 240527586)
  5. GRB 240527A: Fermi GBM Final Real-time Localization
  6. Fermi trigger No 738348224: Global MASTER-Net observations report
  7. Fermi trigger No 738330463: Global MASTER-Net observations report
  8. GRB 240521B: Fermi GBM Observation
  9. Fermi GBM Sub-Threshold Detection of GRB 240516B
  10. GRB 240513A: Swift-XRT afterglow detection
  11. GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
  12. Fermi trigger No 737996942: Global MASTER-Net observations report
  13. GRB 240516B: AstroSat CZTI detection
  14. GRB 240514B: VZLUSAT-2 detection
  15. GRB 240504A: VZLUSAT-2 detection
  16. GRB 240502A: VZLUSAT-2 detection
  17. GRB 240519A: GRBAlpha detection
  18. GRB 240519A: AstroSat CZTI detection
  19. Fermi trigger No 737788024: Global MASTER-Net observations report
  20. GRB 240519A: BALROG localization (Fermi Trigger 737788024 / GRB 240519213)
  21. Fermi GRB 240517A: Global MASTER-Net observations report
  22. GRB 240516A ATCA radio observations
  23. IPN triangulation of GRB 240514B (short)
  24. GRB 240513A: Swift ToO observations
  25. GRB 240517A: Fermi GBM Final Real-time Localization
  26. Konus-Wind detection of GRB 240513A
  27. GRB 240516A: AstroSat CZTI detection
  28. Fermi trigger No 737559855: Global MASTER-Net observations report
  29. GRB 240516A: Fermi GBM Observation
  30. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  31. GRB 240516A: GOTO optical upper limit
  32. Fermi trigger No 737523389: Global MASTER-Net observations report
  33. GRB 240514B: AT2024ixa/GOTO24bph is not consistent with the Fermi localisation
  34. Fermi trigger No 737476171: Global MASTER-Net observations report
  35. GRB 240514B: GOTO candidate optical counterpart
  36. Fermi Gamma-ray Burst Monitor list of triggers that are not a GRB
  37. GRB 240514B: GRBAlpha detection
  38. GRB 240514B: Fermi GBM Detection
  39. GRB 240513A: Fermi GBM observation
  40. GRB 240513A: Swift-XRT observations
  41. GRB 240514C: Fermi GBM Final Real-time Localization
  42. Fermi GRB 240514B: Global MASTER-Net observations report
  43. Fermi Gamma-ray Burst Monitor triggers 737345659/240514093 and GRB240514A are not GRBs
  44. GRB 240514B: Fermi GBM Final Real-time Localization
  45. GRB 240514A: Fermi GBM Final Real-time Localization
  46. GRB 240513A: Tiled Swift observations
  47. GRB 240513A: Fermi-LAT detection
  48. GRB 240511A: Fermi GBM Observation
  49. Fermi GRB 240513B: Global MASTER-Net observations report
  50. Fermi trigger No 737277727: Global MASTER-Net observations report
  51. GRB 240513B: Fermi GBM Final Real-time Localization
  52. GRB 240513A: AstroSat CZTI detection
  53. Fermi trigger No 737258655: Global MASTER-Net observations report
  54. GRB 240511A: J-band observations with WINTER
  55. Fermi trigger No 737247400: Global MASTER-Net observations report
  56. Fermi trigger No 737244199: Global MASTER-Net observations report
  57. Fermi trigger No 737218721: Global MASTER-Net observations report
  58. Fermi trigger No 737196587: Global MASTER-Net observations report
  59. Fermi trigger No 737168073: Global MASTER-Net observations report
  60. GRB 240511A : MITSuME Akeno optical upper limits
  61. GRB 240511A: optical afterglow detection from the NOT
  62. Fermi Gamma-ray Burst Monitor trigger 737102480/240511279 is not a GRB
  63. Fermi Gamma-ray Burst Monitor trigger 737111207/240511380 is not a GRB
  64. Fermi GBM trigger 737105243/240511311 is not a GRB
  65. Fermi trigger No 737173236: Global MASTER-Net observations report
  66. Fermi GRB 240511A: Global MASTER-Net observations report
  67. Fermi trigger No 737105243: Global MASTER-Net observations report
  68. Fermi Gamma-ray Burst Monitor trigger 737133200/240511634 is not a GRB
  69. Fermi trigger No 737152719: Global MASTER-Net observations report
  70. GRB 240511A: Fermi GBM Final Real-time Localization
  71. Fermi trigger No 737102480: Global MASTER-Net observations report
  72. Fermi trigger No 737111207: Global MASTER-Net observations report
  73. Fermi Gamma-ray Burst Monitor trigger 737076431/240510977 is not a GRB
  74. Fermi trigger No 736967879: Global MASTER-Net observations report
  75. Fermi Gamma-ray Burst Monitor trigger 230925241/717313591 is not a GRB
  76. GRB 240504A: Fermi GBM Observation
  77. Fermi Gamma-ray Burst Monitor trigger 736837160/240508208 is not a GRB
  78. Fermi trigger No 736733320: Global MASTER-Net observations report
  79. IPN triangulation of GRB 240504A
  80. GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  81. Fermi GBM triggers 736668287/240506253 and 736669277/240506265 are not GRBs
  82. Fermi trigger No 736564880: Global MASTER-Net observations report
  83. IceCube-240424A: GRANDMA Optical Upper Limit of Fermi J2151.3+0220
  84. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  85. Fermi trigger No 736461232: Global MASTER-Net observations report
  86. IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
  87. Fermi GRB 240504A: Global MASTER-Net observations report
  88. Fermi trigger No 736472503: Global MASTER-Net observations report
  89. GRB 240504A: BALROG localization (Fermi Trigger 736492377 / GRB 240504217)
  90. GRB 240504A: Fermi GBM Final Real-time Localization
  91. Fermi trigger No 736387941: Global MASTER-Net observations report
  92. GRB 240502A: GOTO optical upper limit
  93. Fermi trigger No 736379109: Global MASTER-Net observations report
  94. GRB 240502A: Fermi GBM Observation
  95. GRB 240502C: GOTO possible optical counterpart candidates
  96. Fermi GRB 240502B: Global MASTER-Net observations report
  97. GRB 240502C: Fermi GBM Final Localization
  98. Fermi GRB 240502A: Global MASTER-Net observations report
  99. GRB 240430A: GRBAlpha detection
  100. GRB 240502B: Fermi GBM Final Real-time Localization

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