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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

3533 results found.

  1. IPN triangulation of GRB 211120A
  2. Fermi trigger No 658971499: Global MASTER-Net observations report
  3. Fermi trigger No 658755664: Global MASTER-Net observations report
  4. GRB 211115A: MAXI/GSC detection
  5. Fermi trigger No 658214822: Global MASTER-Net observations report
  6. Fermi GRB 211109B: Global MASTER-Net observations report
  7. GRB 211023A: SAO RAS optical observations
  8. Swift Trigger 1082569 is probably not a GRB
  9. GRB 211023B: Subaru optical observation
  10. GRB 211024A: MITSuME Akeno optical observation
  11. GRB 211023B: MITSuME Akeno optical upper limits
  12. Fermi GRB 211031A: Global MASTER-Net observations report
  13. GRB 211023A: 1.3m DFOT Optical Observations
  14. GRB 211023A: Terskol optical observations
  15. Fermi GRB 211027A: Global MASTER-Net observations report
  16. GRB 210610B: Sintesz-Newton/CrAO optical observations
  17. GRB 211023B: BOOTES-4/MET and 1.5m OSN optical upper limit
  18. GRB 211018A: Fermi GBM observation
  19. GRB 211018A: Fermi-LAT detection
  20. Fermi trigger No 655401471: Global MASTER-Net observations report
  21. Fermi trigger No 654854799: Global MASTER-Net observations report
  22. GRB 210928A: Fermi GBM observation
  23. GRB 210927A: GIT optical follow-up of ZTF21acdwctm.
  24. Fermi GRB 210929B: Global MASTER-Net observations report
  25. GRB 210919A OSN 1.5m Source Confirmation
  26. IceCube Alert 210922.76: Global MASTER-Net observations report
  27. GRB 210919A: Swift detection of a short burst
  28. Konus-Wind observation of the recent SGR 1935+2154 activity
  29. Fermi GBM observation of another bright burst in the direction of SGR 1935+2154
  30. GECAM observations of bursts from SGR J1935+2154 (2021-09-11T07 to 2021-09-12T08)
  31. Fermi trigger No 653084584: Global MASTER-Net observations report
  32. Fermi trigger No 653083551: Global MASTER-Net observations report
  33. Fermi trigger No 653066130: Global MASTER-Net observations report
  34. Fermi trigger No 653022153: Global MASTER-Net observations report
  35. IPN triangulation of a bright burst from SGR 1935+2154
  36. Fermi trigger No 652944960: Global MASTER-Net observations report
  37. Fermi trigger No 652906639: Global MASTER-Net observations report
  38. Fermi trigger No 652585475: Global MASTER-Net observations report
  39. Fermi GRB 210903A: Global MASTER-Net observations report
  40. GRB 210827A: BOOTES-5/JGT optical upper limit
  41. Integral GRB210829.14: Global MASTER-Net observations report
  42. Fermi GRB 210827A: Global MASTER-Net observations report
  43. GRB 210824A: Fermi GBM Observation
  44. GRB 210822B: DDOTI Upper Limits on the Afterglow
  45. Fermi GRB 210822B: Global MASTER-Net observations report
  46. Fermi GRB 210821A: Global MASTER-Net observations report
  47. GRB 210821A: Fermi GBM Final Real-time Localization
  48. Fermi trigger No 651110719: Global MASTER-Net observations report
  49. Fermi GRB 210813A: Global MASTER-Net observations report
  50. GRB 210807A: Tautenburg observations
  51. GRB 210807A: Swift-BAT refined analysis
  52. GRB 210807C: Fermi GBM detection
  53. Fermi GRB 210807C: Global MASTER-Net observations report
  54. Swift GRB 210807A: Global MASTER-Net observations report
  55. IPN Triangulation of a bright burst from SGR 1935+2154
  56. Fermi trigger No 649814537: Global MASTER-Net observations report
  57. GRB 210731A: MeerLICHT optical afterglow detection
  58. GRB210731A: Enhanced Swift-XRT position
  59. Fermi trigger No 648959581: Global MASTER-Net observations report
  60. Fermi trigger No 648868114: Global MASTER-Net observations report
  61. Swift GRB210724.84: Global MASTER-Net observations report
  62. Fermi trigger No 648602917: Global MASTER-Net observations report
  63. Fermi trigger No 648278666: Global MASTER-Net observations report
  64. GRB 210715B: DDOTI Upper Limits on the Afterglow
  65. Fermi trigger No 647942198: Global MASTER-Net observations report
  66. Fermi trigger No 647805873: Global MASTER-Net observations report
  67. Fermi trigger No 647641569: Global MASTER-Net observations report
  68. Fermi trigger No 647624281: Global MASTER-Net observations report
  69. Fermi GRB 210709A: Global MASTER-Net observations report
  70. GRB 210708B: Swift detection of a possible burst
  71. Fermi trigger No 647365516: Global MASTER-Net observations report
  72. Integral GRB210707.02: Global MASTER-Net observations report
  73. Fermi trigger No 647108723: Global MASTER-Net observations report
  74. Fermi trigger No 647120009: Global MASTER-Net observations report
  75. GRB210702A: MeerLICHT multi-colour photometry
  76. GRB 210702A: Swift detection of a burst with a bright optical counterpart
  77. IceCube-210629A: Upper limits from a search for additional neutrino events in IceCube
  78. Fermi trigger No 646443989: Global MASTER-Net observations report
  79. Fermi GRB 210627B: Global MASTER-Net observations report
  80. Fermi GRB 210627A: Global MASTER-Net observations report
  81. GRB 210619B: ASIM observation
  82. Fermi trigger No 646189108: Global MASTER-Net observations report
  83. Fermi trigger No 646194855: Global MASTER-Net observations report
  84. GRB 210619B: Mini-MegaTORTORA early optical observations
  85. GRB 210619B: Ondrejov D50 detection
  86. GRB 210618A: DDOTI upper limit for the optical afterglow
  87. Swift GRB210618.07: Global MASTER-Net observations report
  88. Fermi GRB 210615A: Global MASTER-Net observations report
  89. GRB 210610B: Further SAO RAS optical observations
  90. GRB 201228B: Fermi GBM observation
  91. GRB 210610B: SAO RAS optical observations
  92. GRB 210610A: Swift-BAT refined analysis
  93. Fermi trigger No 645047470: Global MASTER-Net observations report
  94. GRB 210610A: Xinglong-2.16m optical afterglow observations
  95. GRB 210610A: Swift detection of a burst with an optical counterpart
  96. GRB 210607A/MAXI J1733-222: MAXI/GSC detection
  97. GRB 210605B: Swift/BAT-GUANO detection and arcminute localization
  98. Fermi trigger No 644359567: Global MASTER-Net observations report
  99. Fermi GRB 210601A: Global MASTER-Net observations report
  100. Fermi GRB 210529A: Global MASTER-Net observations report

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