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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"

3387 results found.

  1. GRB 210821A: Fermi GBM Final Real-time Localization
  2. Fermi trigger No 651110719: Global MASTER-Net observations report
  3. Fermi GRB 210813A: Global MASTER-Net observations report
  4. GRB 210807A: Tautenburg observations
  5. GRB 210807A: Swift-BAT refined analysis
  6. GRB 210807C: Fermi GBM detection
  7. Fermi GRB 210807C: Global MASTER-Net observations report
  8. Swift GRB 210807A: Global MASTER-Net observations report
  9. IPN Triangulation of a bright burst from SGR 1935+2154
  10. Fermi trigger No 649814537: Global MASTER-Net observations report
  11. GRB 210731A: MeerLICHT optical afterglow detection
  12. GRB210731A: Enhanced Swift-XRT position
  13. Fermi trigger No 648959581: Global MASTER-Net observations report
  14. Fermi trigger No 648868114: Global MASTER-Net observations report
  15. Swift GRB210724.84: Global MASTER-Net observations report
  16. Fermi trigger No 648602917: Global MASTER-Net observations report
  17. Fermi trigger No 648278666: Global MASTER-Net observations report
  18. GRB 210715B: DDOTI Upper Limits on the Afterglow
  19. Fermi trigger No 647942198: Global MASTER-Net observations report
  20. Fermi trigger No 647805873: Global MASTER-Net observations report
  21. Fermi trigger No 647641569: Global MASTER-Net observations report
  22. Fermi trigger No 647624281: Global MASTER-Net observations report
  23. Fermi GRB 210709A: Global MASTER-Net observations report
  24. GRB 210708B: Swift detection of a possible burst
  25. Fermi trigger No 647365516: Global MASTER-Net observations report
  26. Integral GRB210707.02: Global MASTER-Net observations report
  27. Fermi trigger No 647108723: Global MASTER-Net observations report
  28. Fermi trigger No 647120009: Global MASTER-Net observations report
  29. GRB210702A: MeerLICHT multi-colour photometry
  30. GRB 210702A: Swift detection of a burst with a bright optical counterpart
  31. IceCube-210629A: Upper limits from a search for additional neutrino events in IceCube
  32. Fermi trigger No 646443989: Global MASTER-Net observations report
  33. Fermi GRB 210627B: Global MASTER-Net observations report
  34. Fermi GRB 210627A: Global MASTER-Net observations report
  35. GRB 210619B: ASIM observation
  36. Fermi trigger No 646189108: Global MASTER-Net observations report
  37. Fermi trigger No 646194855: Global MASTER-Net observations report
  38. GRB 210619B: Mini-MegaTORTORA early optical observations
  39. GRB 210619B: Ondrejov D50 detection
  40. GRB 210618A: DDOTI upper limit for the optical afterglow
  41. Swift GRB210618.07: Global MASTER-Net observations report
  42. Fermi GRB 210615A: Global MASTER-Net observations report
  43. GRB 210610B: Further SAO RAS optical observations
  44. GRB 201228B: Fermi GBM observation
  45. GRB 210610B: SAO RAS optical observations
  46. GRB 210610A: Swift-BAT refined analysis
  47. Fermi trigger No 645047470: Global MASTER-Net observations report
  48. GRB 210610A: Xinglong-2.16m optical afterglow observations
  49. GRB 210610A: Swift detection of a burst with an optical counterpart
  50. GRB 210607A/MAXI J1733-222: MAXI/GSC detection
  51. GRB 210605B: Swift/BAT-GUANO detection and arcminute localization
  52. Fermi trigger No 644359567: Global MASTER-Net observations report
  53. Fermi GRB 210601A: Global MASTER-Net observations report
  54. Fermi GRB 210529A: Global MASTER-Net observations report
  55. Fermi GRB 210529B: Global MASTER-Net observations report
  56. GRB 210528A: Fermi GBM detection
  57. GRB 210528A: AstroSat CZTI detection
  58. GRB 210528B: MAXI/GSC detection
  59. Fermi GRB 210528A: Global MASTER-Net observations report
  60. GRB 210528A: BALROG localization (Fermi Trigger 643903431 / GRB 210528586)
  61. GRB 210528A: Fermi GBM Final Real-time Localization
  62. GRB 210527A: MITSuME Akeno optical upper limits
  63. Fermi GRB 210518A: Global MASTER-Net observations report
  64. Fermi trigger No 642991619: Global MASTER-Net observations report
  65. GRB 210517A: AGILE detection
  66. GRB 210517A: Swift detection of a burst
  67. Fermi GRB 210515A: Global MASTER-Net observations report
  68. IPN triangulation of GRB 210427A
  69. Fermi GRB 210511A: Global MASTER-Net observations report
  70. Fermi GRB 210510A: Global MASTER-Net observations report
  71. GRB 201228B: Swift/BAT-GUANO archival detection and arcminute localization
  72. Fermi GRB 210507A: Global MASTER-Net observations report
  73. GRB 210504A: Swift detection of a burst
  74. Fermi GRB 210501A: Global MASTER-Net observations report
  75. IPN triangulation of GRB 210424B (short/hard)
  76. Fermi trigger No 640695289: Global MASTER-Net observations report
  77. Swift GRB 210421A: Global MASTER-Net observations report
  78. GRB 210421A: Swift detection of a burst
  79. Fermi GRB 210419B: Global MASTER-Net observations report
  80. GRB 210419B: Fermi GBM Final Real-time Localization
  81. Fermi GRB 210411B: Global MASTER-Net observations report
  82. Fermi GRB 210411A: Global MASTER-Net observations report
  83. GRB 210409A: GECAM detection
  84. Konus-Wind detection of GRB 210406A
  85. Integral GRB210406.72: Global MASTER-Net observations report
  86. Fermi trigger No 639199407: Global MASTER-Net observations report
  87. GRB 210328A: AstroSat CZTI detection
  88. Fermi trigger No 639093861: Global MASTER-Net observations report
  89. GRB 210328A: GECAM detection
  90. GRB 210328A: BALROG localization (Fermi Trigger / GRB 210328865)
  91. GRB 210328A: Fermi GBM Final Real-time Localization
  92. Fermi GRB 210324B: Global MASTER-Net observations report
  93. GRB 210324A: Fermi GBM Final Real-time Localization
  94. IceCube Alert 210322.11: Global MASTER-Net observations report
  95. GRB 210321A: Redshift from OSIRIS/GTC
  96. GRB 210320A: MAXI/GSC detection
  97. Fermi trigger No 637729731: Global MASTER-Net observations report
  98. Fermi trigger No 637521056: Global MASTER-Net observations report
  99. Fermi GRB 210312A: Global MASTER-Net observations report
  100. GRB 171205A: Continued ATCA observations

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