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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"

14820 results found.

  1. IPN triangulation of GRB 240615A (short)
  2. X-ray transient EP240618a: Fermi/GBM non-detection
  3. GRB 240619A: GRBAlpha detection
  4. EP240618a: Swift/XRT upper limit
  5. EP240617a: tentative Swift/XRT detection of the afterglow
  6. GRB 240619A: Swift-XRT probable afterglow detection
  7. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  8. GRB 240619C: NuSTAR automated detection of the GRB
  9. Fermi GBM Sub-Threshold Detection of GRB 240619C
  10. GRB 240619A: GOTO candidate optical afterglow
  11. GRB 240615A: NOT optical observations
  12. GRB 240619C: AstroSat CZTI detection
  13. GRB 240615A: possible transient detection from Wendelstein observations
  14. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  15. EP240618a: BOOTES-6/DPRT optical upper limit
  16. GRB 240619B: Fermi GBM Final Real-time Localization
  17. GRB 240619A: Fermi GBM Final Real-time Localization
  18. EP240617a: BOOTES-6/DPRT optical upper limit
  19. EP240617a is likely a GRB event
  20. EP240617a: EP-WXT detection of a fast X-ray transient
  21. EP240618a: EP-WXT detection of a fast X-ray transient and EP-FXT quick follow-up
  22. GRB 240615A: GECAM detection
  23. Konus-Wind detection of GRB 240615A (short/hard)
  24. GRB 240616A: Fermi GBM Final Real-time Localization
  25. GRB 240615A: Fermi GBM Final Real-time Localization
  26. GRB 240603A: VZLUSAT-2 detection
  27. GRB 240612A: GRBAlpha detection
  28. GRB 240613A: Fermi GBM Final Real-time Localization
  29. GRB 240612B: Fermi GBM Final Real-time Localization
  30. GRB 240612A: Fermi GBM Final Real-time Localization
  31. GRB 240607A: GECAM detection of a bright long burst
  32. Konus-Wind detection of GRB 240607A
  33. GRB 240611A: Fermi GBM Final Real-time Localization
  34. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  35. GRB 240529A: LBT optical detection and late temporal decay
  36. GRB 240529A : MITSuME Akeno optical afterglow detection
  37. Trigger 1236151: Swift detection of EXO 0748-676
  38. GRB 240610A: Fermi GBM Final Real-time Localization
  39. IPN triangulation of GRB 240607A
  40. Konus-Wind detection of GRB 240606B
  41. GRB 240608A: Fermi GBM Final Real-time Localization
  42. GRB 240529A: NOEMA detection
  43. GRB 240607A: AstroSat CZTI detection of bright long burst
  44. GRB 240607A: Fermi GBM detection of a very bright burst
  45. GRB 240529A: radio detection with AMI-LA
  46. GRB 240607A: Fermi GBM Final Real-time Localization
  47. GRB 240606B: GECAM-B detection a long burst
  48. GRB 240606B: Swift-XRT afterglow detection
  49. Konus-Wind detection of GRB 240603A
  50. IPN triangulation of GRB 240531A (short)
  51. GRB 240605C: Fermi GBM Final Real-time Localization
  52. IPN triangulation of GRB 240603A
  53. GRB 240605B: Fermi GBM Final Real-time Localization
  54. GRB 240604A: Fermi GBM Final Localization
  55. GRB 240605A: Fermi GBM Final Real-time Localization
  56. GRB 240604A: GECAM detection of a long burst
  57. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  58. GRB 240603A: Fermi GBM Final Localization
  59. GRB 240603C: Fermi GBM Final Real-time Localization
  60. GRB 240603B: Swift detection of a possible burst
  61. GRB 240529A: MASTER prompt OT detection
  62. GRB 240603A: GECAM detection of a short burst
  63. GRB 240529A: OSN optical detection
  64. The EP-WXT source triggered on June 1st is likely a flaring star
  65. GRB 240602A: Fermi GBM Final Real-time Localization
  66. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  67. LXT 240528A: GSP optical upper limit
  68. GRB 240529A: 1.3m DFOT Optical observations
  69. GRB 240531A: AstroSat CZTI detection of a short burst
  70. Konus-Wind detection of GRB 240529A
  71. IPN triangulation of the initial episode of GRB 240529A
  72. GRB 240529A: MAAO 0.7m telescope optical afterglow detection
  73. GRB 240529A: Insight-HXMT/HE detection
  74. GRB 240529A: optical photometry from Konkoly
  75. GRB 240529A: GROWTH-India optical follow-up
  76. GRB 240529A: T193/MISTRAL observations
  77. GRB 240529A: AKO Optical Afterglow Detection
  78. LXT 240528A: LEIA detection of a fast X-ray transient
  79. GRB240529A: BOOTES-6/DPRT optical detection
  80. GRB 240529A: Swift/UVOT Detection
  81. GRB 240529A: AstroSat CZTI detection
  82. GRB 240529A: GOTO optical afterglow detection
  83. GRB 240527B: Swift-XRT afterglow detection
  84. GRB 240529A: Swift detection of a burst with an optical counterpart
  85. GRB 240527B: Fermi-LAT detection
  86. GRB 240527B: Fermi GBM Final Localization
  87. GRB 240527A: Fermi GBM Final Real-time Localization
  88. GRB 240523A: Swift detection of a burst
  89. Fermi GBM Sub-Threshold Detection of GRB 240516B
  90. GRB 240513A: Swift-XRT afterglow detection
  91. EP240518a: GSP optical upper limit
  92. GRB 240521A: GECAM-B detection of a long burst
  93. GRB 240516B: AstroSat CZTI detection
  94. GRB 240514B: VZLUSAT-2 detection
  95. GRB 240504A: VZLUSAT-2 detection
  96. GRB 240502A: VZLUSAT-2 detection
  97. GRB 240519A: GRBAlpha detection
  98. GRB 240519A: AstroSat CZTI detection
  99. EP240518a: possibly identified with a flare star by EP-FXT
  100. EP240518a: EP-WXT detection of a new X-ray transient

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