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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"

3838 results found.

  1. IceCube-221229A: Upper limits from a search for additional neutrino events in IceCube
  2. Fermi-LAT gamma-ray observations of IceCube-221229A
  3. IceCube-221229A: BOOTES-2/TELMA Optical Upper Limit
  4. IceCube-221229A - IceCube observation of a high-energy neutrino candidate track-like event
  5. Fermi GRB 221226A: Global MASTER-Net observations report
  6. GRB 221218A: 3.6m DOT optical upper limit
  7. Fermi trigger No 692713692: Global MASTER-Net observations report
  8. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 December 13
  9. Fermi GRB 221211A: Global MASTER-Net observations report
  10. IceCube Alert 221210.36: Global MASTER-Net observations report
  11. GRB 221202A: VLT/FORS2 Afterglow Discovery
  12. GRB 221201A: Fermi GBM observation
  13. GRB 221126A: AGILE detection
  14. IceCube-221124A: BOOTES-4/MET and BOOTES-2/TELMA optical upper limit
  15. GRB 221126A: Swift/BAT-GUANO detection outside the coded FOV
  16. GRB 221126A: Fermi GBM Final Real-time Localization
  17. GRB 221120A: Detection by VZLUSAT-2
  18. IPN triangulation of GRB 221121A (long)
  19. GRB 221120A: Fermi GBM observation
  20. GRB 221120A: Swift detection of a likely short burst
  21. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 November 9
  22. GRB 221110A: COATLI Afterglow detection
  23. GRB 221110A: Swift detection of a burst with an optical counterpart
  24. Swift GRB221110.10: Global MASTER-Net OT detection
  25. Swift GRB221110.10: Global MASTER-Net observations report
  26. Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
  27. GRB 221029A: CALET Gamma-Ray Burst Monitor detection
  28. GRB 221029A: Fermi GBM observation
  29. GRB 221029A: Fermi GBM Final Localization
  30. GRB 221029A: Detection by GRBAlpha
  31. GRB 221028A: COATLI Upper Limits
  32. Konus-Wind detection of GRB 221017A
  33. GRB 221027A: Fermi GBM detection
  34. GRB 221024A: Mondy optical observations
  35. IPN triangulation of GRB 221022C (short)
  36. SGR 1935+2154: AstroSat CZTI Detections
  37. GRB 221009A: SARA-RM 1m Optical Afterglow Detection
  38. Fermi Gamma-ray Burst Monitor detections of SGR 1935+2154
  39. SGR 1935+21542: VZLUSAT-2 and GRBAlpha joint detection
  40. GRB 221017A: CALET Gamma-Ray Burst Monitor detection
  41. AGILE detection of a burst from SGR J1935+2154 reported by VZLUSAT-2
  42. GRB 221009A: Continued LDT Afterglow Monitoring
  43. SGR 1935+2154: Bursting activity detected by VZLUSAT-2
  44. AGILE detection of the 2022 October 17 burst from SGR J1935+2154 reported by Konus-Wind
  45. SGR 1935+2154: Detection by GRBAlpha
  46. The probability of observing GRB 221009A at z = 0.151
  47. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 October 17
  48. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  49. IPN triangulation of GRB 221017A (long)
  50. Konus-Wind detection of a short burst coincident with a bright radio burst from SGR 1935+2154
  51. GRB 221009A: continued Assy optical afterglow observations, possible SN evidence
  52. Konus-Wind observation of the recent SGR 1935+2154 activity
  53. Fermi Gamma-ray Burst Monitor detections of SGR 1935+2154
  54. GRB 221014A: Fermi GBM Final Real-time Localization
  55. Fermi Gamma-ray Burst Monitor continues to detect SGR 1935+2154
  56. Fermi trigger No 687345829: Global MASTER-Net observations report
  57. Fermi trigger No 687344475: Global MASTER-Net observations report
  58. Fermi trigger No 687340841: Global MASTER-Net observations report
  59. Fermi trigger No 687337536: Global MASTER-Net observations report
  60. Integral GRB221013.00: Global MASTER-Net observations report
  61. Afterglow limits of GRB 221006A from OHP
  62. Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
  63. INTEGRAL shows increasing activity in SGR J1935+2154
  64. Fermi trigger No 687205006: Global MASTER-Net observations report
  65. INTEGRAL detection of a burst from SGR J1935+2154
  66. GRB 220829A: Detection by GRBAlpha
  67. INTEGRAL detection of a burst from SGR J1935+2154
  68. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  69. GRB 221009A (Swift J1913.1+1946): MeerLICHT observations
  70. GRB 221006A: Swift-XRT observations
  71. GRB 221006A: MAXI/GSC detection
  72. Fermi GBM trigger 686350260/221001869 is not a GRB
  73. Fermi trigger No 686403226: Global MASTER-Net observations report
  74. Fermi trigger No 686350260: Global MASTER-Net observations report
  75. IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube
  76. Fermi GRB 220925A: Global MASTER-Net observations report
  77. Fermi trigger No 685748699: Global MASTER-Net observations report
  78. GRB 220921A: MeerLICHT afterglow observations
  79. Fermi trigger No 685452089: Global MASTER-Net observations report
  80. Fermi trigger No 684894705: Global MASTER-Net observations report
  81. Konus-Wind detection of GRB 220910A
  82. Fermi GRB 220912A: Global MASTER-Net observations report
  83. IPN triangulation of GRB 220905A
  84. Fermi GRB 220905A: Global MASTER-Net observations report
  85. Fermi GRB 220902A: Global MASTER-Net observations report
  86. Fermi trigger No 683654200: Global MASTER-Net observations report
  87. IceCube-Cascade 220826A: Upper limits from a search for additional neutrino events in IceCube
  88. Fermi trigger No 683202084: Global MASTER-Net observations report
  89. Fermi trigger No 683183601: Global MASTER-Net observations report
  90. Fermi trigger No 683152759: Global MASTER-Net observations report
  91. Fermi trigger No 682918137: Global MASTER-Net observations report
  92. IceCube Alert 220822.85: Global MASTER-Net observations report
  93. GRB 220730A: Swift-BAT refined analysis
  94. GRB 220730A: Swift-XRT afterglow detection
  95. GRB 220730A: Swift-XRT observations
  96. GRB 220729A: AstroSat CZTI detection
  97. GRB 220730A: Swift detection of a short hard burst
  98. Fermi trigger No 680782656: Global MASTER-Net observations report
  99. Fermi GRB 220728A: Global MASTER-Net observations report
  100. Fermi GRB 220721A: Global MASTER-Net observations report

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