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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"

36111 results found.

  1. GRB 211225B: Swift detection of a burst
  2. GRB 211225A/MAXI J0827-071: MAXI/GSC detection
  3. GRB 211224A: Fermi GBM Final Real-time Localization
  4. GRB 211106A: Third HST Observation
  5. GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
  6. GRB 211223C: Swift-BAT refined analysis
  7. GRB 211223C: BOOTES-4/MET optical upper limit
  8. Swift GRB 211223C: Global MASTER-Net observations report
  9. GRB 211223A: Insight-HXMT/HE detection
  10. Fermi GRB 211223B: Global MASTER-Net observations report
  11. Fermi GBM Sub-Threshold Detection of GRB 211221A
  12. Fermi GBM Sub-Threshold Detection of GRB 211207A
  13. GRB 211221A: Swift-BAT refined analysis
  14. GRB 211223C: Swift detection of a burst
  15. GRB 211223B: Fermi GBM Final Real-time Localization
  16. GRB 211223A: GECAM detection
  17. GRB 211221A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  18. GRB 211219B: AstroSat CZTI detection
  19. GRB 211219A: AstroSat CZTI detection
  20. Fermi GRB 211222A: Global MASTER-Net observations report
  21. GRB 211221A: Swift-XRT refined Analysis
  22. GRB 211222A: Fermi GBM Final Real-time Localization
  23. GRB 211221A: BOOTES-4/MET optical upper limit
  24. GRB 211218A: MITSuME Akeno optical upper limits
  25. GRB 211221A: MeerLICHT optical limits
  26. GRB 211221A: NOT optical limits
  27. GRB 211221A: Enhanced Swift-XRT position
  28. Swift GRB 211221A: Global MASTER-Net observations report
  29. GRB 211221A: Swift detection of a burst
  30. GRB 211219A: AGILE detection
  31. GRB 211219A: Swift/BAT-GUANO detection outside the coded FOV
  32. Fermi GRB 211219B: Global MASTER-Net observations report
  33. GRB 211219B: Fermi GBM Final Real-time Localization
  34. Fermi GRB 211219A: Global MASTER-Net observations report
  35. GRB 211219A: Fermi GBM Final Real-time Localization
  36. GRB 211211A: MMT/MMIRS Observations Indicate Fading of K-band Source
  37. GRB 211216A: Fermi GBM observation
  38. GRB 211218A, MAXI J0909-041: MAXI/GSC detection
  39. GRB 211106A: XMM-Newton monitoring campaign detections
  40. IceCube-211216B: Upper limits from Fermi-GBM Observations
  41. IceCube-211216A: Upper limits from Fermi-GBM Observations
  42. GRB 211217A: GECAM detection
  43. GRB 211216A: Swift/BAT-GUANO detection outside the coded FOV
  44. Fermi GRB 211216B: Global MASTER-Net observations report
  45. GRB 211216B: GECAM detection
  46. GRB 211216B: Fermi GBM Final Real-time Localization
  47. IceCube-211216A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  48. GRB 211211A: TNG NIR observations
  49. GRB 211216A: GECAM detection
  50. GRB 211216A: BALROG localization (Fermi Trigger 661329957 / GRB 211216282)
  51. Fermi GRB 211216A: Global MASTER-Net observations report
  52. GRB 211216A: Fermi GBM Final Real-time Localization
  53. GRB 211211A: Insight-HXMT/HE detection
  54. GRB 211211A - Gemini K-band detection
  55. GRB 211211A: SAO RAS optical observations
  56. GRB 211211A: AbAO optical observations
  57. GRB 211211A: GMG upper limit
  58. GRB 211211A: redshift estimation and SPI-ACS/INTEGRAL detection
  59. GRB 211211A: Very fast decay observed from CAFOS/2.2mCAHA
  60. GRB 211211A: Further observations from CAFOS/2.2m CAHA
  61. GRB 211211A: HCT and GIT optical follow up observations
  62. GRB 211211A: CALET Gamma-Ray Burst Monitor detection
  63. Fermi GRB 211212A: Global MASTER-Net observations report
  64. GRB 211211A: incorrect E_iso value in GCN 31221
  65. GRB 211211A: Swift/UVOT detection
  66. GRB 211211A: NOT optical spectroscopy
  67. GRB 211211B: GECAM detection
  68. Fermi GRB 211212B: Global MASTER-Net observations report
  69. GRB 211211A: Afterglow detection from CAFOS/2.2m CAHA
  70. GRB 211211A: MITSuME Akeno optical observation
  71. Swift GRB 211211A: Global MASTER-Net observations report
  72. GRB 211212B: Fermi GBM Final Real-time Localization
  73. GRB 211211A: LCO Optical Observations
  74. GRB 211211A: Nanshan/NEXT optical observations
  75. GRB 211211A: Swift-XRT refined Analysis
  76. GRB 211212A: Fermi GBM Final Real-time Localization
  77. GRB 211211A: Fermi GBM observation
  78. GRB 211211A: Swift-BAT refined analysis
  79. Fermi GRB 211211B: Global MASTER-Net observations report
  80. GRB 211211B: Fermi GBM Final Real-time Localization
  81. Fermi GRB 211211A: Global MASTER-Net observations report
  82. GRB 211211A: Enhanced Swift-XRT position
  83. GRB 211207A: Swift/UVOT Detection
  84. GRB 211211A: KAIT Optical Afterglow Candidate
  85. GRB 211211A: Swift detection of a bright burst
  86. GRB 211211A: Fermi GBM Final Real-time Localization
  87. GRB 211130A: MeerLICHT identification of possible afterglow candidate
  88. IceCube-211208A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  89. GRB 211207A: Swift-BAT refined analysis
  90. GRB 211207A: VLT/X-shooter redshift
  91. GRB 211204C: Fermi GBM detection
  92. GRB 211207A: Swift-XRT refined Analysis
  93. GRB 211207A: Enhanced Swift-XRT position
  94. Swift GRB 211207A: Global MASTER-Net observations report
  95. GRB 211207A: Swift detection of a burst with an optical counterpart
  96. GRB 211206A: Not observable by Fermi-GBM
  97. GRB 211206A: AstroSat CZTI detection
  98. GRB 211206B: AstroSat CZTI detection
  99. GRB 211204C: AstroSat CZTI detection
  100. IPN triangulation of GRB 211204C

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