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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"

19725 results found.

  1. GRB 220527A: Swift ToO observations
  2. Fermi-LAT Gamma-ray Observations of IceCube-220524A
  3. IPN triangulation of GRB 220524A
  4. GRB 220521A: MITSuME Akeno optical upper limits
  5. GRB 220521A: REM optical/NIR upper limits
  6. GRB 220521A: RATIR Optical and NIR Observations
  7. GRB 220521A: Swift/UVOT Upper Limits
  8. GRB 220521A: SAO RAS optical observations
  9. GRB 220521A: Enhanced Swift-XRT position
  10. GRB 220521A: NOT optical afterglow detection
  11. GRB 220521A: Swift detection of a burst
  12. GRB 220514A: AstroSat CZTI detection
  13. Continued Chandra monitoring of GW170817 at ~4.8 yr post-merger
  14. GRB 220518A: Swift/UVOT Detection
  15. GRB 220518A: Enhanced Swift-XRT position
  16. GRB 220518A: Swift detection of a burst
  17. GRB 220514A: MITSuME Akeno optical observation
  18. GRB 220514A: GRANDMA Optical Afterglow Observations
  19. Fermi trigger No 674397342: Global MASTER-Net observations report
  20. GRB 220514B: Swift-XRT observations
  21. GRB 220511A: Swift-XRT afterglow detection
  22. Fermi-LAT Gamma-ray Observations of IceCube-220513A
  23. GRB 220514B: Tiled Swift observations
  24. IceCube-220513A: No significant detection in HAWC
  25. GRB 220514A: MeerLICHT optical afterglow candidate
  26. IceCube-220509A: No significant detection in HAWC
  27. GRB 220511A: Swift ToO observations
  28. Fermi-LAT Gamma-ray Observations of IceCube-220509A
  29. GRB 220506A: MITSuME Akeno optical upper limits
  30. GRB 220506A: GIT optical upper limit.
  31. GRB 220508A: Fermi GBM Final Real-time Localization
  32. GRB 220506A: Tiled Swift observations
  33. GRB 220430A: Nanshan/NEXT optical upper limit
  34. GRB 220430A: Nanshan/HMT optical upper limit
  35. GRB 220430A: GIT optical upper limits
  36. IPN triangulation of GRB 220423A
  37. Fermi-LAT Gamma-ray Observations of IceCube-220501A
  38. GRB 220427A: GRANDMA Early Optical Afterglow Detection
  39. GRB 220501A: GRANDMA/TJML Optical Observations
  40. GRB 220430A: Mondy and AbAO optical upper limits
  41. GRB 220430A: MeerLICHT optical upper limits
  42. GRB 220430A: Enhanced Swift-XRT position
  43. GRB 220430A: Swift detection of a burst or Swift J0630.4+0932
  44. GRB 220427A: Swift-BAT refined analysis
  45. GRB 220427A: VLT/X-shooter photometry
  46. GRB 220427A: Enhanced Swift-XRT position
  47. GRB 220426A: Tiled Swift observations
  48. GRB 220427A: Swift detection of a burst with an optical counterpart
  49. IPN triangulation of GRB 220426A
  50. Fermi-LAT Gamma-ray Observations of IceCube-220425A
  51. Correction to 31937: GRB 220421B: Detection by VZLUSAT-2
  52. Fermi-LAT Gamma-ray Observations of IceCube-220424A
  53. Fermi-LAT Gamma-ray Observations of IceCube-220421A
  54. GRB 220418B: Swift ToO observations
  55. GRB 220412B: Swift/UVOT Upper Limits
  56. GRB 220408B: Fermi GBM observation
  57. GRB 220412B: TNG optical observations
  58. GRB 220412A: GRANDMA observations
  59. GRB 220412A: Continued RATIR Observations and Steepening of the Light Curve
  60. GRB 220412A: RATIR Observations of the Fading Afterglow
  61. GRB 220412B: Swift-XRT observations
  62. GRB 220408B: Fermi-LAT detection
  63. IPN triangulation of short/soft GRB 220406A
  64. GRB 220412B: GIT optical upper limit
  65. GRB 220412A: MITSuME Akeno optical upper limits
  66. GRB 220412B: MITSuME Akeno optical upper limits
  67. GRB 220412A: Enhanced Swift-XRT position
  68. GRB 220412B: Swift detection of a short burst
  69. GRB 220412A: Swift/UVOT Upper Limits
  70. GRB 220408A: GRANDMA observations
  71. GRB 220403B: GRANDMA observations
  72. GRB 220412A: RATIR Afterglow Candidate
  73. GRB 220412A: Swift detection of a burst
  74. IPN triangulation of GRB 220403C
  75. GRB 220403B: Swift/UVOT Detection
  76. GRB 220408A: RATIR Optical and NIR Observations
  77. GRB 220408A: 1.3m DFOT Optical upper limit
  78. GRB 220408A: NOT optical observations and archival detection
  79. GRB 220403C: Swift ToO observations
  80. GRB 220408A: BOOTES-5/JGT optical afterglow detection
  81. GRB 220408A: GIT optical upper limit
  82. GRB 220408A: Fermi GBM observation
  83. GRB 220408A: Swift/UVOT Detection
  84. GRB 220408B: Fermi GBM Final Localization
  85. GRB 220408A: Xinglong-2.16m optical upper limit
  86. GRB 220408A: Enhanced Swift-XRT position
  87. GRB 220408A: Swift detection of a burst with an optical counterpart, possibly associated with M51
  88. GRB 220408A: Fermi GBM Final Real-time Localization
  89. GRB 220403B: Mondy optical upper limit
  90. GRB 220403B: Kitab optical observations
  91. Fermi-LAT Gamma-ray Observations of IceCube-220405A
  92. GRB 220403B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  93. GRB 220403B: LBT observations
  94. GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
  95. GRB 220403A: Tautenburg observations
  96. GRB 220403B: Swift detection of a burst with an optical counterpart
  97. Swift Trigger 1100848 is likely not a GRB
  98. Fermi GRB 220330A: Global MASTER-Net observations report
  99. GRB 220325A: GRANDMA observations
  100. GRB 220325A: Swift/UVOT Upper Limits

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