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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"

39457 results found.

  1. GRB 220101A: Fermi GBM Detection
  2. GRB 220101A: NOT redshift confirmation
  3. GRB 220101A: CAHA 2.2m/CAFOS detection
  4. GRB 220101A: Liverpool telescope imaging of a high-redshift afterglow
  5. GRB 220101A: THO optical observations
  6. GRB 220101A: Swift-XRT refined Analysis
  7. GRB 220101A: AGILE detection
  8. GRB 220101A: Xinglong-2.16m photometry and spectroscopy
  9. Swift GRB220101.22: Global MASTER-Net observations report
  10. GRB 220101: Swift/UVOT Detection
  11. GRB 220101A: Fermi-LAT detection
  12. GRB 220101A: Enhanced Swift-XRT position
  13. GRB 220101A: Correction to GCN 31347
  14. GRB 220101A: Swift detection of a burst with a bright optical counterpart
  15. IPN triangulation of GRB 211219A
  16. GRB 211231A: GECAM detection
  17. GRB 211229B: AGILE detection
  18. GRB 211231A: Fermi GBM Final Real-time Localization
  19. GRB 211229A: Swift-XRT and UVOT observations
  20. GRB 211227A: Deep early CAHA 2.2m/CAFOS observation
  21. GRB 211229A: Fermi GBM observation
  22. GRB 211229B: GECAM detection
  23. GRB 211229C: Swift/BAT-GUANO detection likely outside the coded FOV
  24. Fermi GRB 211229B: Global MASTER-Net observations report
  25. GRB 211229B: Fermi GBM Final Real-time Localization
  26. GRB 211229A: Swift ToO observations
  27. GRB 211229A: Swift/BAT-GUANO arcminute localization
  28. GRB 211227A: CALET Gamma-Ray Burst Monitor detection
  29. GRB 211225B: CALET Gamma-Ray Burst Monitor detection
  30. GRB 211229A: GECAM detection
  31. Fermi GRB 211229A: Global MASTER-Net observations report
  32. GRB 211229A: Fermi GBM Final Real-time Localization
  33. GRB 211227A: Swift/UVOT Upper Limits
  34. GRB 211227A: Swift-XRT refined Analysis
  35. GRB 211227A: Swift-BAT refined analysis
  36. GRB 211227A: A possible short GRB with extended emission at z = 0.228?
  37. GRB 211227A: Liverpool Telescope upper limits
  38. GRB 211227A: Enhanced Swift-XRT position
  39. GRB 211227A: LCO Optical Observations
  40. GRB 211227A: Nanshan/NEXT optical observations and host galaxy candidate
  41. GRB 211227A: MAXI/GSC detection
  42. GRB 211227A: BOOTES-2/TELMA optical upper limit
  43. GRB 211221A: Swift/UVOT Upper Limits
  44. GRB 211227A: Swift detection of a burst
  45. Swift GRB211227.98: Global MASTER-Net observations report
  46. IceCube-20211216B: observations of SN2021gpw in the errorbox of the neutrino trigger
  47. GRB 211226A: Swift/BAT-GUANO detection outside the coded FOV
  48. GRB 211225B: Swift-BAT refined analysis
  49. Fermi trigger No 662216114: Global MASTER-Net observations report
  50. GRB 211225A: MITSuME Akeno optical upper limits
  51. GRB 211226A: AGILE/MCAL detection of a burst
  52. Swift GRB 211225B: Global MASTER-Net observations report
  53. Fermi GRB 211225C: Global MASTER-Net observations report
  54. GRB 211225C: Fermi GBM Final Real-time Localization
  55. GRB 211225B: Swift detection of a burst
  56. MAXI GRB211225.14: Global MASTER-Net observations report
  57. GRB 211225A/MAXI J0827-071: MAXI/GSC detection
  58. Fermi trigger No 662084433: Global MASTER-Net observations report
  59. GRB 211224A: Fermi GBM Final Real-time Localization
  60. GRB 211106A: Third HST Observation
  61. GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
  62. Fermi trigger No 662010159: Global MASTER-Net observations report
  63. GRB 211223C: Swift-BAT refined analysis
  64. GRB 211223C: BOOTES-4/MET optical upper limit
  65. Swift GRB 211223C: Global MASTER-Net observations report
  66. GRB 211223A: Insight-HXMT/HE detection
  67. Fermi GRB 211223B: Global MASTER-Net observations report
  68. Fermi GBM Sub-Threshold Detection of GRB 211221A
  69. Fermi GBM Sub-Threshold Detection of GRB 211207A
  70. GRB 211221A: Swift-BAT refined analysis
  71. GRB 211223C: Swift detection of a burst
  72. GRB 211223B: Fermi GBM Final Real-time Localization
  73. GRB 211223A: GECAM detection
  74. GRB 211221A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  75. GRB 211219B: AstroSat CZTI detection
  76. GRB 211219A: AstroSat CZTI detection
  77. Fermi GRB 211222A: Global MASTER-Net observations report
  78. GRB 211221A: Swift-XRT refined Analysis
  79. GRB 211222A: Fermi GBM Final Real-time Localization
  80. GRB 211221A: BOOTES-4/MET optical upper limit
  81. GRB 211218A: MITSuME Akeno optical upper limits
  82. GRB 211221A: MeerLICHT optical limits
  83. GRB 211221A: NOT optical limits
  84. GRB 211221A: Enhanced Swift-XRT position
  85. Swift GRB 211221A: Global MASTER-Net observations report
  86. GRB 211221A: Swift detection of a burst
  87. GRB 211219A: AGILE detection
  88. GRB 211219A: Swift/BAT-GUANO detection outside the coded FOV
  89. Fermi GRB 211219B: Global MASTER-Net observations report
  90. GRB 211219B: Fermi GBM Final Real-time Localization
  91. Fermi GRB 211219A: Global MASTER-Net observations report
  92. GRB 211219A: Fermi GBM Final Real-time Localization
  93. GRB 211211A: MMT/MMIRS Observations Indicate Fading of K-band Source
  94. GRB 211216A: Fermi GBM observation
  95. GRB 211218A, MAXI J0909-041: MAXI/GSC detection
  96. MAXI GRB211218.04: Global MASTER-Net observations report
  97. GRB 211106A: XMM-Newton monitoring campaign detections
  98. Fermi-LAT Gamma-ray Observations of IceCube-211216B
  99. Fermi-LAT Gamma-ray Observations of IceCube-211216A
  100. IceCube-211216B: Upper limits from Fermi-GBM Observations

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