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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"

39496 results found.

  1. GRB 210321A: Swift detection of a burst
  2. GRB 210320A: MAXI/GSC detection
  3. GRB 210318B: MITSuME Okayama optical upper limits
  4. GRB 201216C: VIRT optical observations
  5. GRB 200524A: Redshift from Gemini-North
  6. GRB 210318A: Swift-BAT refined analysis
  7. GRB 210318A: Swift-XRT refined Analysis
  8. GRB 210318A: Enhanced Swift-XRT position
  9. Swift GRB210318.13: Global MASTER-Net observations report
  10. GRB 210318B: Fermi GBM detection
  11. Fermi trigger No 637729731: Global MASTER-Net observations report
  12. GRB 210318B: Swift-BAT refined analysis
  13. Swift GRB 210318A: Global MASTER-Net observations report
  14. Konus-Wind detection of GRB 210318B
  15. GRB210318B: Swift detection of a burst
  16. GRB 210318A: Swift detection of a burst
  17. Fermi GRB 210317A: Global MASTER-Net observations report
  18. GRB 210317A: GECAM detection
  19. GRB 210317A: Fermi GBM Final Real-time Localization
  20. Fermi trigger No 637521056: Global MASTER-Net observations report
  21. GRB 210306A: GIT optical follow-up
  22. GRB 210226A: GIT optical upper limit
  23. GRB 210312B: Redshift from OSIRIS/GTC
  24. GRB 210306A: HCT optical upper limit
  25. GRB 210312B: GTC photometry
  26. GRB 210312B: MASTER OT confirmation
  27. GRB210312B (Integral alert 9073): Candidate optical afterglow by Ondrejov D50
  28. GRB 210312B: A long GRB detected by INTEGRAL
  29. Integral GRB210312.87: Global MASTER-Net observations report
  30. Fermi GRB 210312A: Global MASTER-Net observations report
  31. GRB 210312A: Fermi GBM Final Real-time Localization
  32. GRB 210306A: LBT observations
  33. GRB 210306A: Tautenburg observations
  34. Konus-Wind detection of GRB 210308A
  35. Konus-Wind detection of GRB 210306A
  36. Konus-Wind detection of GRB 210305A
  37. GRB 171205A: Continued ATCA observations
  38. Fermi trigger No 637027080: Global MASTER-Net observations report
  39. GRB 210306A: Early Spectroscopy of the Optical Afterglow
  40. GRB 210306B: Fermi GBM detection
  41. GRB 210306A: Swift/UVOT Detection
  42. GRB 210306A: continued Mondy optical observations
  43. GRB 210308A: Mondy and AbAO optical observations
  44. GRB 210308A: Swift-BAT refined analysis
  45. GRB 210307A: Swift-BAT refined analysis
  46. Fermi trigger No 636926765: Global MASTER-Net observations report
  47. GRB 210308A: Swift/UVOT Detection
  48. GRB 210307A: Swift/UVOT Upper Limits
  49. GRB 210305A: Fermi GBM observation
  50. Swift GRB 210308A: Global MASTER-Net observations report
  51. GRB 210308A: Fermi GBM detection
  52. GRB 210305A: Swift-XRT refined Analysis
  53. GRB 210307A: Swift-XRT refined Analysis
  54. GRB 210308A: Nanshan/NEXT optical upper limits
  55. GRB 210306A: Swift-XRT refined Analysis
  56. GRB 210308A: MITSuME Okayama optical upper limits
  57. GRB 210306A: continued Mondy optical observations
  58. GRB 210308A: Swift detection of a burst with an optical counterpart
  59. GRB 210306A: 1.3m DFOT observations
  60. GRB 210306A: Swift-BAT refined analysis
  61. GRB 210306A: Mondy optical observations
  62. GRB 210305A: Swift/UVOT Upper Limits
  63. GRB 210307B: GECAM detection
  64. GRB 210307A: LCO Optical Upper Limits
  65. GRB 210306B: Swift-BAT refined analysis
  66. GRB 210305A: Swift-BAT refined analysis
  67. GRB 210307A: Swift detection of a burst
  68. Swift GRB210307.36: Global MASTER-Net observations report
  69. GRB 210306A: MITSuME Akeno optical observation
  70. GRB 210306A: NEXT optical observations
  71. Swift GRB 210306A: Global MASTER-Net observations report
  72. GRB 210306A: Fermi GBM observation
  73. GRB 210306A: Tautenburg observations
  74. GRB 210306A: iTelescope T24 optical observations
  75. GRB 210306A: Fermi-LAT detection
  76. GRB 210306B: Swift detection of a burst
  77. GRB 210306A: LCO Optical Afterglow Detection
  78. GRB 210306A: iTelescope optical afterglow observations
  79. GRB 210306A: DDOTI Afterglow Confirmation
  80. GRB 210306A: Swift detection of a burst with a bright optical counterpart
  81. Swift GRB 210305A: Global MASTER-Net observations report
  82. GRB 210305A: Swift detection of a burst
  83. GRB 210228B: Insight-HXMT/HE detection
  84. Fermi trigger No 636459103: Global MASTER-Net observations report
  85. GRB 210217A: 3.6m DOT optical observations
  86. GRB 210226A: Swift/UVOT Upper Limits
  87. Fermi trigger No 636187116: Global MASTER-Net observations report
  88. GRB 210228A: GECAM detection
  89. Fermi trigger No 636168178: Global MASTER-Net observations report
  90. Integral GRB210227.20: Global MASTER-Net observations report
  91. GRB 210225A: Insight-HXMT/HE detection
  92. INTEGRAL IBAS Alert n.9020 not a GRB
  93. Integral GRB210227.20: Global MASTER-Net observations report
  94. Integral GRB210227.19: Global MASTER-Net observations report
  95. Integral GRB210227.19: Global MASTER-Net OT detection
  96. GRB 210226A: Swift-BAT refined analysis
  97. GRB 210226A: Fermi GBM detection
  98. GRB 210217A: Mondy optical observations
  99. GRB 210226A: KAIT Optical Upper Limit
  100. GRB 210226A: Swift-XRT refined Analysis

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