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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"

39464 results found.

  1. GRB 220101A: GMG observation (2nd epoch)
  2. GRB 211231A: AstroSat CZTI detection
  3. GRB 220101A: OASDG optical observations
  4. GRB 220101A : Eiso equals the maximum isotropic GRB energy
  5. GRB 220101A: GMG observation
  6. GRB 220101A: Asiago spectroscopic and photometric detection
  7. Fermi trigger No 662768315: Global MASTER-Net observations report
  8. GRB 220101A: Fermi GBM Detection
  9. GRB 220101A: NOT redshift confirmation
  10. GRB 220101A: CAHA 2.2m/CAFOS detection
  11. GRB 220101A: Liverpool telescope imaging of a high-redshift afterglow
  12. GRB 220101A: THO optical observations
  13. GRB 220101A: Swift-XRT refined Analysis
  14. GRB 220101A: AGILE detection
  15. GRB 220101A: Xinglong-2.16m photometry and spectroscopy
  16. Swift GRB220101.22: Global MASTER-Net observations report
  17. GRB 220101: Swift/UVOT Detection
  18. GRB 220101A: Fermi-LAT detection
  19. GRB 220101A: Enhanced Swift-XRT position
  20. GRB 220101A: Correction to GCN 31347
  21. GRB 220101A: Swift detection of a burst with a bright optical counterpart
  22. IPN triangulation of GRB 211219A
  23. GRB 211231A: GECAM detection
  24. GRB 211229B: AGILE detection
  25. GRB 211231A: Fermi GBM Final Real-time Localization
  26. GRB 211229A: Swift-XRT and UVOT observations
  27. GRB 211227A: Deep early CAHA 2.2m/CAFOS observation
  28. GRB 211229A: Fermi GBM observation
  29. GRB 211229B: GECAM detection
  30. GRB 211229C: Swift/BAT-GUANO detection likely outside the coded FOV
  31. Fermi GRB 211229B: Global MASTER-Net observations report
  32. GRB 211229B: Fermi GBM Final Real-time Localization
  33. GRB 211229A: Swift ToO observations
  34. GRB 211229A: Swift/BAT-GUANO arcminute localization
  35. GRB 211227A: CALET Gamma-Ray Burst Monitor detection
  36. GRB 211225B: CALET Gamma-Ray Burst Monitor detection
  37. GRB 211229A: GECAM detection
  38. Fermi GRB 211229A: Global MASTER-Net observations report
  39. GRB 211229A: Fermi GBM Final Real-time Localization
  40. GRB 211227A: Swift/UVOT Upper Limits
  41. GRB 211227A: Swift-XRT refined Analysis
  42. GRB 211227A: Swift-BAT refined analysis
  43. GRB 211227A: A possible short GRB with extended emission at z = 0.228?
  44. GRB 211227A: Liverpool Telescope upper limits
  45. GRB 211227A: Enhanced Swift-XRT position
  46. GRB 211227A: LCO Optical Observations
  47. GRB 211227A: Nanshan/NEXT optical observations and host galaxy candidate
  48. GRB 211227A: MAXI/GSC detection
  49. GRB 211227A: BOOTES-2/TELMA optical upper limit
  50. GRB 211221A: Swift/UVOT Upper Limits
  51. GRB 211227A: Swift detection of a burst
  52. Swift GRB211227.98: Global MASTER-Net observations report
  53. IceCube-20211216B: observations of SN2021gpw in the errorbox of the neutrino trigger
  54. GRB 211226A: Swift/BAT-GUANO detection outside the coded FOV
  55. GRB 211225B: Swift-BAT refined analysis
  56. Fermi trigger No 662216114: Global MASTER-Net observations report
  57. GRB 211225A: MITSuME Akeno optical upper limits
  58. GRB 211226A: AGILE/MCAL detection of a burst
  59. Swift GRB 211225B: Global MASTER-Net observations report
  60. Fermi GRB 211225C: Global MASTER-Net observations report
  61. GRB 211225C: Fermi GBM Final Real-time Localization
  62. GRB 211225B: Swift detection of a burst
  63. MAXI GRB211225.14: Global MASTER-Net observations report
  64. GRB 211225A/MAXI J0827-071: MAXI/GSC detection
  65. Fermi trigger No 662084433: Global MASTER-Net observations report
  66. GRB 211224A: Fermi GBM Final Real-time Localization
  67. GRB 211106A: Third HST Observation
  68. GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
  69. Fermi trigger No 662010159: Global MASTER-Net observations report
  70. GRB 211223C: Swift-BAT refined analysis
  71. GRB 211223C: BOOTES-4/MET optical upper limit
  72. Swift GRB 211223C: Global MASTER-Net observations report
  73. GRB 211223A: Insight-HXMT/HE detection
  74. Fermi GRB 211223B: Global MASTER-Net observations report
  75. Fermi GBM Sub-Threshold Detection of GRB 211221A
  76. Fermi GBM Sub-Threshold Detection of GRB 211207A
  77. GRB 211221A: Swift-BAT refined analysis
  78. GRB 211223C: Swift detection of a burst
  79. GRB 211223B: Fermi GBM Final Real-time Localization
  80. GRB 211223A: GECAM detection
  81. GRB 211221A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  82. GRB 211219B: AstroSat CZTI detection
  83. GRB 211219A: AstroSat CZTI detection
  84. Fermi GRB 211222A: Global MASTER-Net observations report
  85. GRB 211221A: Swift-XRT refined Analysis
  86. GRB 211222A: Fermi GBM Final Real-time Localization
  87. GRB 211221A: BOOTES-4/MET optical upper limit
  88. GRB 211218A: MITSuME Akeno optical upper limits
  89. GRB 211221A: MeerLICHT optical limits
  90. GRB 211221A: NOT optical limits
  91. GRB 211221A: Enhanced Swift-XRT position
  92. Swift GRB 211221A: Global MASTER-Net observations report
  93. GRB 211221A: Swift detection of a burst
  94. GRB 211219A: AGILE detection
  95. GRB 211219A: Swift/BAT-GUANO detection outside the coded FOV
  96. Fermi GRB 211219B: Global MASTER-Net observations report
  97. GRB 211219B: Fermi GBM Final Real-time Localization
  98. Fermi GRB 211219A: Global MASTER-Net observations report
  99. GRB 211219A: Fermi GBM Final Real-time Localization
  100. GRB 211211A: MMT/MMIRS Observations Indicate Fading of K-band Source

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