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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"

37767 results found.

  1. GRB 240516A ATCA radio observations
  2. IPN triangulation of GRB 240514B (short)
  3. GRB 240513A: Swift ToO observations
  4. GRB 240517A: Fermi GBM Final Real-time Localization
  5. Konus-Wind detection of GRB 240513A
  6. GRB 240516A: AstroSat CZTI detection
  7. GRB 240516A: Swift-XRT refined Analysis
  8. GRB 240514E: A possible candidate BD-21 1074
  9. Fermi trigger No 737559855: Global MASTER-Net observations report
  10. GRB 240516A: Fermi GBM Observation
  11. GRB 240511A: Observations from GTC/OSIRIS+
  12. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  13. GRB 240516A: GOTO optical upper limit
  14. LIGO/Virgo/KAGRA S240422ed: GRID non-detection and upper limits
  15. Fermi trigger No 737523389: Global MASTER-Net observations report
  16. GRB 240516A: Swift detection of a burst
  17. GRB 240514B: AT2024ixa/GOTO24bph is not consistent with the Fermi localisation
  18. Fermi trigger No 737476171: Global MASTER-Net observations report
  19. GRB 240511A: radio detection of afterglow candidate
  20. GRB 240514B: GOTO candidate optical counterpart
  21. Fermi Gamma-ray Burst Monitor list of triggers that are not a GRB
  22. GRB 240514E: MAXI/GSC detection of a probable afterglow
  23. GRB 240514B: GRBAlpha detection
  24. GRB 240514B: Fermi GBM Detection
  25. GRB 240513A: Fermi GBM observation
  26. GRB 240513A: Swift-XRT observations
  27. GRB 240514D: AstroSat CZTI detection
  28. GRB 240514C: Fermi GBM Final Real-time Localization
  29. Fermi GRB 240514B: Global MASTER-Net observations report
  30. Fermi Gamma-ray Burst Monitor triggers 737345659/240514093 and GRB240514A are not GRBs
  31. GRB 240514B: Fermi GBM Final Real-time Localization
  32. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  33. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  34. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  35. GRB 240514A: Fermi GBM Final Real-time Localization
  36. GRB 240513A: Tiled Swift observations
  37. GRB 240513A: Fermi-LAT detection
  38. GRB 240511A: Fermi GBM Observation
  39. GRB 240511A: Swift-BAT refined analysis
  40. Fermi GRB 240513B: Global MASTER-Net observations report
  41. Fermi trigger No 737277727: Global MASTER-Net observations report
  42. GRB 240513B: Fermi GBM Final Real-time Localization
  43. GRB 240513A: AstroSat CZTI detection
  44. Fermi trigger No 737258655: Global MASTER-Net observations report
  45. GRB 240511A: J-band observations with WINTER
  46. Fermi trigger No 737247400: Global MASTER-Net observations report
  47. Fermi trigger No 737244199: Global MASTER-Net observations report
  48. Fermi trigger No 737218721: Global MASTER-Net observations report
  49. Fermi trigger No 737196587: Global MASTER-Net observations report
  50. Fermi trigger No 737168073: Global MASTER-Net observations report
  51. GRB 240511A: Enhanced Swift-XRT position
  52. GRB 240511A : MITSuME Akeno optical upper limits
  53. GRB 240511A: Swift-XRT refined Analysis
  54. GRB 240511A: optical afterglow detection from the NOT
  55. Fermi Gamma-ray Burst Monitor trigger 737102480/240511279 is not a GRB
  56. Fermi Gamma-ray Burst Monitor trigger 737111207/240511380 is not a GRB
  57. Fermi GBM trigger 737105243/240511311 is not a GRB
  58. Fermi trigger No 737173236: Global MASTER-Net observations report
  59. Fermi GRB 240511A: Global MASTER-Net observations report
  60. Swift GRB 240511A: Global MASTER-Net observations report
  61. Fermi trigger No 737105243: Global MASTER-Net observations report
  62. Fermi Gamma-ray Burst Monitor trigger 737133200/240511634 is not a GRB
  63. Fermi trigger No 737152719: Global MASTER-Net observations report
  64. GRB 240511A: Prompt enhanced Swift-XRT position
  65. GRB 240511A: Swift detection of a burst
  66. GRB 240511A: Fermi GBM Final Real-time Localization
  67. Fermi trigger No 737102480: Global MASTER-Net observations report
  68. Fermi trigger No 737111207: Global MASTER-Net observations report
  69. Fermi Gamma-ray Burst Monitor trigger 737076431/240510977 is not a GRB
  70. Fermi trigger No 736967879: Global MASTER-Net observations report
  71. Fermi Gamma-ray Burst Monitor trigger 230925241/717313591 is not a GRB
  72. EP240506a: CrAO ZTSH optical upper limit
  73. GRB 240504A: Fermi GBM Observation
  74. Fermi Gamma-ray Burst Monitor trigger 736837160/240508208 is not a GRB
  75. Fermi trigger No 736733320: Global MASTER-Net observations report
  76. IPN triangulation of GRB 240504A
  77. GRB 240502A: 1.3m DFOT Optical upper limit
  78. GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  79. Fermi GBM triggers 736668287/240506253 and 736669277/240506265 are not GRBs
  80. Fermi trigger No 736564880: Global MASTER-Net observations report
  81. IceCube-240424A: GRANDMA Optical Upper Limit of Fermi J2151.3+0220
  82. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  83. Fermi trigger No 736461232: Global MASTER-Net observations report
  84. IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
  85. Fermi GRB 240504A: Global MASTER-Net observations report
  86. Fermi trigger No 736472503: Global MASTER-Net observations report
  87. GRB 240503A: AstroSat CZTI detection
  88. GRB 240504A: BALROG localization (Fermi Trigger 736492377 / GRB 240504217)
  89. GRB 240504A: Fermi GBM Final Real-time Localization
  90. Fermi trigger No 736387941: Global MASTER-Net observations report
  91. LXT 240402A / GRB 240402B: VLT X-shooter redshift of host
  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 240415A 1.3m DFOT Optical upper limit
  96. GRB 240502C: GOTO possible optical counterpart candidates
  97. Fermi GRB 240502B: Global MASTER-Net observations report
  98. GRB 240502C: Fermi GBM Final Localization
  99. Fermi GRB 240502A: Global MASTER-Net observations report
  100. GRB 240501B: GRBAlpha detection

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