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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"

36397 results found.

  1. GRB 240513A: Swift ToO observations
  2. GRB 240517A: Fermi GBM Final Real-time Localization
  3. Konus-Wind detection of GRB 240513A
  4. GRB 240516A: AstroSat CZTI detection
  5. GRB 240516A: Swift-XRT refined Analysis
  6. GRB 240514E: A possible candidate BD-21 1074
  7. GRB 240516A: Fermi GBM Observation
  8. GRB 240511A: Observations from GTC/OSIRIS+
  9. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  10. GRB 240516A: GOTO optical upper limit
  11. LIGO/Virgo/KAGRA S240422ed: GRID non-detection and upper limits
  12. GRB 240516A: Swift detection of a burst
  13. GRB 240514B: AT2024ixa/GOTO24bph is not consistent with the Fermi localisation
  14. GRB 240511A: radio detection of afterglow candidate
  15. GRB 240514B: GOTO candidate optical counterpart
  16. Fermi Gamma-ray Burst Monitor list of triggers that are not a GRB
  17. GRB 240514E: MAXI/GSC detection of a probable afterglow
  18. GRB 240514B: GRBAlpha detection
  19. GRB 240514B: Fermi GBM Detection
  20. GRB 240513A: Fermi GBM observation
  21. GRB 240513A: Swift-XRT observations
  22. GRB 240514D: AstroSat CZTI detection
  23. GRB 240514C: Fermi GBM Final Real-time Localization
  24. Fermi GRB 240514B: Global MASTER-Net observations report
  25. GRB 240514B: Fermi GBM Final Real-time Localization
  26. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  27. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  28. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  29. GRB 240514A: Fermi GBM Final Real-time Localization
  30. GRB 240513A: Tiled Swift observations
  31. GRB 240513A: Fermi-LAT detection
  32. GRB 240511A: Fermi GBM Observation
  33. GRB 240511A: Swift-BAT refined analysis
  34. Fermi GRB 240513B: Global MASTER-Net observations report
  35. GRB 240513B: Fermi GBM Final Real-time Localization
  36. GRB 240513A: AstroSat CZTI detection
  37. GRB 240511A: J-band observations with WINTER
  38. GRB 240511A: Enhanced Swift-XRT position
  39. GRB 240511A : MITSuME Akeno optical upper limits
  40. GRB 240511A: Swift-XRT refined Analysis
  41. GRB 240511A: optical afterglow detection from the NOT
  42. Fermi Gamma-ray Burst Monitor trigger 737102480/240511279 is not a GRB
  43. Fermi Gamma-ray Burst Monitor trigger 737111207/240511380 is not a GRB
  44. Fermi GBM trigger 737105243/240511311 is not a GRB
  45. Fermi GRB 240511A: Global MASTER-Net observations report
  46. Swift GRB 240511A: Global MASTER-Net observations report
  47. Fermi Gamma-ray Burst Monitor trigger 737133200/240511634 is not a GRB
  48. GRB 240511A: Prompt enhanced Swift-XRT position
  49. GRB 240511A: Swift detection of a burst
  50. GRB 240511A: Fermi GBM Final Real-time Localization
  51. Fermi Gamma-ray Burst Monitor trigger 737076431/240510977 is not a GRB
  52. Fermi Gamma-ray Burst Monitor trigger 230925241/717313591 is not a GRB
  53. EP240506a: CrAO ZTSH optical upper limit
  54. GRB 240504A: Fermi GBM Observation
  55. Fermi Gamma-ray Burst Monitor trigger 736837160/240508208 is not a GRB
  56. IPN triangulation of GRB 240504A
  57. GRB 240502A: 1.3m DFOT Optical upper limit
  58. GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  59. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  60. IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
  61. Fermi GRB 240504A: Global MASTER-Net observations report
  62. GRB 240503A: AstroSat CZTI detection
  63. GRB 240504A: BALROG localization (Fermi Trigger 736492377 / GRB 240504217)
  64. GRB 240504A: Fermi GBM Final Real-time Localization
  65. LXT 240402A / GRB 240402B: VLT X-shooter redshift of host
  66. GRB 240502A: GOTO optical upper limit
  67. GRB 240502A: Fermi GBM Observation
  68. GRB 240415A 1.3m DFOT Optical upper limit
  69. GRB 240502C: GOTO possible optical counterpart candidates
  70. Fermi GRB 240502B: Global MASTER-Net observations report
  71. GRB 240502C: Fermi GBM Final Localization
  72. Fermi GRB 240502A: Global MASTER-Net observations report
  73. GRB 240501B: GRBAlpha detection
  74. GRB 240430A: GRBAlpha detection
  75. GRB 240502B: Fermi GBM Final Real-time Localization
  76. GRB 240502A long GRB detected by INTEGRAL
  77. GRB 240502A: Fermi GBM Final Real-time Localization
  78. Fermi GRB 240501A: Global MASTER-Net observations report
  79. GRB 240426A: VZLUSAT-2 detection
  80. GRB 240425A: VZLUSAT-2 detection
  81. GRB240430A: Fermi GBM Final Localization
  82. GRB 240501B: AstroSat CZTI detection
  83. GRB 240501A: Fermi GBM Final Real-time Localization
  84. GRB 240408B: VZLUSAT-2 detection
  85. GRB 240407A: VZLUSAT-2 detection
  86. X-ray transient EP240414a: Detection of associated supernova
  87. GRB 240425A: GRBAlpha detection
  88. GRB 240429A: Fermi GBM Final Real-time Localization
  89. Fermi GRB 240428A: Global MASTER-Net observations report
  90. GRB 240428A: Fermi GBM Final Real-time Localization
  91. GRB 240426A: AstroSat CZTI detection
  92. EP240426a: YAHPT optical upper limit
  93. GRB 240414A: NOEMA detection
  94. IceCube-240424A: Upper limits from a search for additional neutrino events in IceCube
  95. LIGO/Virgo/KAGRA S240422ed: Upper limits from GECAM Observations
  96. GRB 240425A: Fermi GBM Final Real-time Localization
  97. GRB 240419B: Swift-BAT refined analysis
  98. GRB 240421B: Swift-BAT refined analysis
  99. GRB 240422A: Glowbug gamma-ray detection
  100. IceCube-240424A - IceCube observation of a high-energy neutrino candidate track-like event

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