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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"

4254 results found.

  1. GRB 230205A: Swift detection of a burst
  2. GRB 230204B: MAXI/GSC detection
  3. IceCube-230201A: Upper limits from a search for additional neutrino events in IceCube
  4. ZTF23aabmzlp/AT2023azs: Lulin 1m LOT optical observations
  5. ZTF23aabmzlp/AT2023azs: AMI-LA radio upper limit
  6. ZTF23aabmzlp/AT2023azs: LCOGT Optical Detection
  7. ZTF23aabmzlp/AT2023azs: Mondy and AbAO optical observations
  8. GRB 230129A: AstroSat CZTI detection
  9. GRB 230129A: Fermi GBM Final Real-time Localization
  10. GRB 230116D: 3.6m DOT optical upper limit
  11. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-221229A
  12. GRB 230111A: MAXI/GSC detection
  13. IceCube-221223A: JCMT/SCUBA2 observations
  14. Fermi Gamma-ray Burst Monitor trigger 694043024/221229905 is not a GRB
  15. GRB 221231A: 3.6m DOT optical upper limit
  16. Subject: IceCube-Cascade 221229A: Upper limits from a search for additional neutrino events in IceCube
  17. IceCube-221229A: Upper limits from a search for additional neutrino events in IceCube
  18. Fermi-LAT gamma-ray observations of IceCube-221229A
  19. IceCube-221229A: BOOTES-2/TELMA Optical Upper Limit
  20. IceCube-221229A - IceCube observation of a high-energy neutrino candidate track-like event
  21. Fermi GRB 221226A: Global MASTER-Net observations report
  22. GRB 221218A: 3.6m DOT optical upper limit
  23. Fermi trigger No 692713692: Global MASTER-Net observations report
  24. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 December 13
  25. Fermi GRB 221211A: Global MASTER-Net observations report
  26. IceCube Alert 221210.36: Global MASTER-Net observations report
  27. GRB 221202A: VLT/FORS2 Afterglow Discovery
  28. GRB 221201A: Fermi GBM observation
  29. GRB 221126A: AGILE detection
  30. IceCube-221124A: BOOTES-4/MET and BOOTES-2/TELMA optical upper limit
  31. GRB 221126A: Swift/BAT-GUANO detection outside the coded FOV
  32. GRB 221126A: Fermi GBM Final Real-time Localization
  33. GRB 221120A: Detection by VZLUSAT-2
  34. IPN triangulation of GRB 221121A (long)
  35. GRB 221120A: Fermi GBM observation
  36. GRB 221120A: Swift detection of a likely short burst
  37. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 November 9
  38. GRB 221110A: COATLI Afterglow detection
  39. GRB 221110A: Swift detection of a burst with an optical counterpart
  40. Swift GRB221110.10: Global MASTER-Net OT detection
  41. Swift GRB221110.10: Global MASTER-Net observations report
  42. Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
  43. GRB 221029A: CALET Gamma-Ray Burst Monitor detection
  44. GRB 221029A: Fermi GBM observation
  45. GRB 221029A: Fermi GBM Final Localization
  46. GRB 221029A: Detection by GRBAlpha
  47. GRB 221028A: COATLI Upper Limits
  48. Konus-Wind detection of GRB 221017A
  49. GRB 221027A: Fermi GBM detection
  50. GRB 221024A: Mondy optical observations
  51. IPN triangulation of GRB 221022C (short)
  52. SGR 1935+2154: AstroSat CZTI Detections
  53. GRB 221009A: SARA-RM 1m Optical Afterglow Detection
  54. Fermi Gamma-ray Burst Monitor detections of SGR 1935+2154
  55. SGR 1935+21542: VZLUSAT-2 and GRBAlpha joint detection
  56. GRB 221017A: CALET Gamma-Ray Burst Monitor detection
  57. AGILE detection of a burst from SGR J1935+2154 reported by VZLUSAT-2
  58. GRB 221009A: Continued LDT Afterglow Monitoring
  59. SGR 1935+2154: Bursting activity detected by VZLUSAT-2
  60. AGILE detection of the 2022 October 17 burst from SGR J1935+2154 reported by Konus-Wind
  61. SGR 1935+2154: Detection by GRBAlpha
  62. The probability of observing GRB 221009A at z = 0.151
  63. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 October 17
  64. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  65. IPN triangulation of GRB 221017A (long)
  66. Konus-Wind detection of a short burst coincident with a bright radio burst from SGR 1935+2154
  67. GRB 221009A: continued Assy optical afterglow observations, possible SN evidence
  68. Konus-Wind observation of the recent SGR 1935+2154 activity
  69. Fermi Gamma-ray Burst Monitor detections of SGR 1935+2154
  70. GRB 221014A: Fermi GBM Final Real-time Localization
  71. Fermi Gamma-ray Burst Monitor continues to detect SGR 1935+2154
  72. Fermi trigger No 687345829: Global MASTER-Net observations report
  73. Fermi trigger No 687344475: Global MASTER-Net observations report
  74. Fermi trigger No 687340841: Global MASTER-Net observations report
  75. Fermi trigger No 687337536: Global MASTER-Net observations report
  76. Integral GRB221013.00: Global MASTER-Net observations report
  77. Afterglow limits of GRB 221006A from OHP
  78. Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
  79. INTEGRAL shows increasing activity in SGR J1935+2154
  80. Fermi trigger No 687205006: Global MASTER-Net observations report
  81. INTEGRAL detection of a burst from SGR J1935+2154
  82. GRB 220829A: Detection by GRBAlpha
  83. INTEGRAL detection of a burst from SGR J1935+2154
  84. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  85. GRB 221009A (Swift J1913.1+1946): MeerLICHT observations
  86. GRB 221006A: Swift-XRT observations
  87. GRB 221006A: MAXI/GSC detection
  88. Fermi GBM trigger 686350260/221001869 is not a GRB
  89. Fermi trigger No 686403226: Global MASTER-Net observations report
  90. Fermi trigger No 686350260: Global MASTER-Net observations report
  91. IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube
  92. Fermi GRB 220925A: Global MASTER-Net observations report
  93. Fermi trigger No 685748699: Global MASTER-Net observations report
  94. GRB 220921A: MeerLICHT afterglow observations
  95. Fermi trigger No 685452089: Global MASTER-Net observations report
  96. Fermi trigger No 684894705: Global MASTER-Net observations report
  97. Konus-Wind detection of GRB 220910A
  98. Fermi GRB 220912A: Global MASTER-Net observations report
  99. IPN triangulation of GRB 220905A
  100. Fermi GRB 220905A: Global MASTER-Net observations report

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