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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"

27776 results found.

  1. GRB 240603A: VZLUSAT-2 detection
  2. GRB 240612A: GRBAlpha detection
  3. GRB 240613A: Fermi GBM Final Real-time Localization
  4. GRB 240612B: Fermi GBM Final Real-time Localization
  5. GRB 240612A: Fermi GBM Final Real-time Localization
  6. GRB 240607A: GECAM detection of a bright long burst
  7. Konus-Wind detection of GRB 240607A
  8. GRB 240611A: Fermi GBM Final Real-time Localization
  9. EXO 0748-676: Swift-BAT refined analysis
  10. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  11. GRB 240529A: LBT optical detection and late temporal decay
  12. GRB 240529A : MITSuME Akeno optical afterglow detection
  13. Trigger 1236151: Swift detection of EXO 0748-676
  14. GRB 240610A: Fermi GBM Final Real-time Localization
  15. IPN triangulation of GRB 240607A
  16. Konus-Wind detection of GRB 240606B
  17. GRB 240608A: Fermi GBM Final Real-time Localization
  18. GRB 240529A: NOEMA detection
  19. GRB 240606B: Fermi GBM Observation
  20. Swift Trigger 1235109: consistent with noise and not astrophysical
  21. GRB 240607A: AstroSat CZTI detection of bright long burst
  22. GRB 240607A: Fermi GBM detection of a very bright burst
  23. GRB 240529A: radio detection with AMI-LA
  24. GRB 240607A: Fermi GBM Final Real-time Localization
  25. GRB 240606B: GECAM-B detection a long burst
  26. GRB 240606B: Swift-XRT afterglow detection
  27. Swift GRB240606.15: Global MASTER-Net observations report
  28. GRB 240606B: Swift ToO observations
  29. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  30. Konus-Wind detection of GRB 240603A
  31. Swift Trigger 1235109: a possible GRB 240606A
  32. IPN triangulation of GRB 240531A (short)
  33. GRB 240605C: Fermi GBM Final Real-time Localization
  34. IPN triangulation of GRB 240603A
  35. GRB 240605B: Fermi GBM Final Real-time Localization
  36. GRB 240604A: Fermi GBM Final Localization
  37. GRB 240605A: Fermi GBM Final Real-time Localization
  38. GRB 240604A: GECAM detection of a long burst
  39. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  40. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  41. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  42. GRB 240603A: Fermi GBM Final Localization
  43. GRB 240603C: Fermi GBM Final Real-time Localization
  44. Swift Trigger 1232465: consistent with noise
  45. GRB 240603B: Swift detection of a possible burst
  46. GRB 240529A: MASTER prompt OT detection
  47. GRB 240603A: GECAM detection of a short burst
  48. GRB 240529A: OSN optical detection
  49. The EP-WXT source triggered on June 1st is likely a flaring star
  50. GRB 240602A: Fermi GBM Final Real-time Localization
  51. Swift Trigger 1232465 is not a GRB
  52. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  53. LXT 240528A: GSP optical upper limit
  54. GRB 240529A: 1.3m DFOT Optical observations
  55. GRB 240531A: AstroSat CZTI detection of a short burst
  56. Konus-Wind detection of GRB 240529A
  57. IPN triangulation of the initial episode of GRB 240529A
  58. GRB 240529A: MAAO 0.7m telescope optical afterglow detection
  59. GRB 240529A: Insight-HXMT/HE detection
  60. GRB 240529A: optical photometry from Konkoly
  61. GRB 240529A: GROWTH-India optical follow-up
  62. GRB 240529A: T193/MISTRAL observations
  63. GRB 240529A: AKO Optical Afterglow Detection
  64. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  65. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  66. GRB 240529A: Skynet Optical Observations
  67. LXT 240528A: LEIA detection of a fast X-ray transient
  68. GRB 240529A: Swift-BAT refined analysis
  69. GRB 240529A: Swift-XRT refined Analysis
  70. GRB240529A: BOOTES-6/DPRT optical detection
  71. GRB 240529A: Swift/UVOT Detection
  72. GRB 240529A: NOT optical observations
  73. GRB 240529A: AstroSat CZTI detection
  74. GRB 240529A: GOTO optical afterglow detection
  75. GRB 240527B: Swift-XRT afterglow detection
  76. GRB 240529A: Enhanced Swift-XRT position
  77. GRB 240529A: Swift detection of a burst with an optical counterpart
  78. Swift GRB240529.12: Global MASTER-Net observations report
  79. GRB 240527B: Fermi-LAT detection
  80. GRB 240527B: Fermi GBM Final Localization
  81. GRB 240527A: Fermi GBM Final Real-time Localization
  82. GRB 240523A: Swift-BAT refined analysis
  83. GRB 240523A: Swift-XRT refined Analysis
  84. GRB 240523A: Enhanced Swift-XRT position
  85. GRB 240523A: Swift detection of a burst
  86. GRB 240521B: Fermi GBM Observation
  87. Fermi GBM Sub-Threshold Detection of GRB 240516B
  88. GRB 240513A: Swift-XRT afterglow detection
  89. GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
  90. EP240518a: GSP optical upper limit
  91. GRB 240521A: GECAM-B detection of a long burst
  92. GRB 240516B: AstroSat CZTI detection
  93. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  94. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  95. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  96. GRB 240514B: VZLUSAT-2 detection
  97. GRB 240504A: VZLUSAT-2 detection
  98. GRB 240502A: VZLUSAT-2 detection
  99. GRB 240519A: GRBAlpha detection
  100. GRB 240516A: Swift/UVOT Upper Limits

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