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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"

39491 results found.

  1. GRB 210318A: Swift-BAT refined analysis
  2. GRB 210318A: Swift-XRT refined Analysis
  3. GRB 210318A: Enhanced Swift-XRT position
  4. Swift GRB210318.13: Global MASTER-Net observations report
  5. GRB 210318B: Fermi GBM detection
  6. Fermi trigger No 637729731: Global MASTER-Net observations report
  7. GRB 210318B: Swift-BAT refined analysis
  8. Swift GRB 210318A: Global MASTER-Net observations report
  9. Konus-Wind detection of GRB 210318B
  10. GRB210318B: Swift detection of a burst
  11. GRB 210318A: Swift detection of a burst
  12. Fermi GRB 210317A: Global MASTER-Net observations report
  13. GRB 210317A: GECAM detection
  14. GRB 210317A: Fermi GBM Final Real-time Localization
  15. Fermi trigger No 637521056: Global MASTER-Net observations report
  16. GRB 210306A: GIT optical follow-up
  17. GRB 210226A: GIT optical upper limit
  18. GRB 210312B: Redshift from OSIRIS/GTC
  19. GRB 210306A: HCT optical upper limit
  20. GRB 210312B: GTC photometry
  21. GRB 210312B: MASTER OT confirmation
  22. GRB210312B (Integral alert 9073): Candidate optical afterglow by Ondrejov D50
  23. GRB 210312B: A long GRB detected by INTEGRAL
  24. Integral GRB210312.87: Global MASTER-Net observations report
  25. Fermi GRB 210312A: Global MASTER-Net observations report
  26. GRB 210312A: Fermi GBM Final Real-time Localization
  27. GRB 210306A: LBT observations
  28. GRB 210306A: Tautenburg observations
  29. Konus-Wind detection of GRB 210308A
  30. Konus-Wind detection of GRB 210306A
  31. Konus-Wind detection of GRB 210305A
  32. GRB 171205A: Continued ATCA observations
  33. Fermi trigger No 637027080: Global MASTER-Net observations report
  34. GRB 210306A: Early Spectroscopy of the Optical Afterglow
  35. GRB 210306B: Fermi GBM detection
  36. GRB 210306A: Swift/UVOT Detection
  37. GRB 210306A: continued Mondy optical observations
  38. GRB 210308A: Mondy and AbAO optical observations
  39. GRB 210308A: Swift-BAT refined analysis
  40. GRB 210307A: Swift-BAT refined analysis
  41. Fermi trigger No 636926765: Global MASTER-Net observations report
  42. GRB 210308A: Swift/UVOT Detection
  43. GRB 210307A: Swift/UVOT Upper Limits
  44. GRB 210305A: Fermi GBM observation
  45. Swift GRB 210308A: Global MASTER-Net observations report
  46. GRB 210308A: Fermi GBM detection
  47. GRB 210305A: Swift-XRT refined Analysis
  48. GRB 210307A: Swift-XRT refined Analysis
  49. GRB 210308A: Nanshan/NEXT optical upper limits
  50. GRB 210306A: Swift-XRT refined Analysis
  51. GRB 210308A: MITSuME Okayama optical upper limits
  52. GRB 210306A: continued Mondy optical observations
  53. GRB 210308A: Swift detection of a burst with an optical counterpart
  54. GRB 210306A: 1.3m DFOT observations
  55. GRB 210306A: Swift-BAT refined analysis
  56. GRB 210306A: Mondy optical observations
  57. GRB 210305A: Swift/UVOT Upper Limits
  58. GRB 210307B: GECAM detection
  59. GRB 210307A: LCO Optical Upper Limits
  60. GRB 210306B: Swift-BAT refined analysis
  61. GRB 210305A: Swift-BAT refined analysis
  62. GRB 210307A: Swift detection of a burst
  63. Swift GRB210307.36: Global MASTER-Net observations report
  64. GRB 210306A: MITSuME Akeno optical observation
  65. GRB 210306A: NEXT optical observations
  66. Swift GRB 210306A: Global MASTER-Net observations report
  67. GRB 210306A: Fermi GBM observation
  68. GRB 210306A: Tautenburg observations
  69. GRB 210306A: iTelescope T24 optical observations
  70. GRB 210306A: Fermi-LAT detection
  71. GRB 210306B: Swift detection of a burst
  72. GRB 210306A: LCO Optical Afterglow Detection
  73. GRB 210306A: iTelescope optical afterglow observations
  74. GRB 210306A: DDOTI Afterglow Confirmation
  75. GRB 210306A: Swift detection of a burst with a bright optical counterpart
  76. Swift GRB 210305A: Global MASTER-Net observations report
  77. GRB 210305A: Swift detection of a burst
  78. GRB 210228B: Insight-HXMT/HE detection
  79. Fermi trigger No 636459103: Global MASTER-Net observations report
  80. GRB 210217A: 3.6m DOT optical observations
  81. GRB 210226A: Swift/UVOT Upper Limits
  82. Fermi trigger No 636187116: Global MASTER-Net observations report
  83. GRB 210228A: GECAM detection
  84. Fermi trigger No 636168178: Global MASTER-Net observations report
  85. Integral GRB210227.20: Global MASTER-Net observations report
  86. GRB 210225A: Insight-HXMT/HE detection
  87. INTEGRAL IBAS Alert n.9020 not a GRB
  88. Integral GRB210227.20: Global MASTER-Net observations report
  89. Integral GRB210227.19: Global MASTER-Net observations report
  90. Integral GRB210227.19: Global MASTER-Net OT detection
  91. GRB 210226A: Swift-BAT refined analysis
  92. GRB 210226A: Fermi GBM detection
  93. GRB 210217A: Mondy optical observations
  94. GRB 210226A: KAIT Optical Upper Limit
  95. GRB 210226A: Swift-XRT refined Analysis
  96. Swift GRB 210226A: Global MASTER-Net observations report
  97. GRB 210218A: Swift-XRT confirmation of afterglow
  98. GRB 210226A: Burke-Gaffney Observatory optical upper limit
  99. GRB 210226A: Enhanced Swift-XRT position
  100. GRB 210226A: Ondrejov BART/SBT optical limit

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