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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"

5859 results found.

  1. Fermi GRB 210827A: Global MASTER-Net observations report
  2. GRB 210827A: Swift/BAT-GUANO detection and arcminute localization
  3. GRB 210827A: Fermi GBM Final Real-time Localization
  4. Swift GRB 210824A: Global MASTER-Net observations report
  5. GRB 210824A: Enhanced Swift-XRT position
  6. GRB 210824A: Swift detection of a burst
  7. Konus-Wind detection of GRB 210822A
  8. GRB 210822A: AstroSat CZTI detection
  9. GRB 210822A: Fermi-LAT detection
  10. Fermi GRB 210822B: Global MASTER-Net observations report
  11. GRB 210822A: KAIT Optical Afterglow Confirmation
  12. GRB 210822A: Swift detection of a burst with an optical afterglow
  13. GRB 210820A: Swift detection of a burst with an optical counterpart
  14. GRB 210818A: Swift detection of a burst with an optical counterpart
  15. GRB 210712A: Fermi GBM observation
  16. Fermi GRB 210813A: Global MASTER-Net observations report
  17. GRB 210807A: continued Assy, AbAO and Mondy observations
  18. Fermi GRB 210807C: Global MASTER-Net observations report
  19. GRB 210807C: Swift detection of a burst
  20. Fermi trigger No 650046564: Global MASTER-Net observations report
  21. GRB 210807A: Swift detection of a burst with an optical counterpart
  22. Fermi trigger No 649814537: Global MASTER-Net observations report
  23. Fermi trigger No 649684549: Global MASTER-Net observations report
  24. Fermi trigger No 649627691: Global MASTER-Net observations report
  25. GRB 210731A: MASTER optical afterglow detection
  26. Trigger 1062273: Swift detection of 4U 1700-377
  27. GRB 210730A: TNG optical observations
  28. GRB 210727A: AstroSat CZTI detection
  29. GRB 210727A: CALET Gamma-Ray Burst Monitor detection
  30. IPN triangulation of GRB 210727A (short)
  31. GRB 210727A: AGILE/MCAL detection
  32. Fermi trigger No 649072251: Global MASTER-Net observations report
  33. GRB 210727A: BALROG localization (Fermi Trigger 649072251 / GRB 210727410)
  34. Fermi trigger No 648959581: Global MASTER-Net observations report
  35. GRB 210724A: Afterglow candidate from OSIRIS/GTC
  36. GRB 210724A: Swift detection of a burst
  37. GRB 210722A: Redshift from OSIRIS/GTC
  38. GRB 210723A: Swift detection of a burst
  39. Fermi trigger No 648602917: Global MASTER-Net observations report
  40. GRB 210715B: DDOTI Upper Limits on the Afterglow
  41. Fermi trigger No 648033323: Global MASTER-Net observations report
  42. Fermi trigger No 648024201: Global MASTER-Net observations report
  43. Fermi trigger No 647942198: Global MASTER-Net observations report
  44. GRB 210712A: Swift detection of a burst
  45. GRB 210709A: AstroSat CZTI detection
  46. Fermi trigger No 647624281: Global MASTER-Net observations report
  47. Fermi trigger No 647522278: Global MASTER-Net observations report
  48. Fermi GRB 210709A: Global MASTER-Net observations report
  49. GRB 210708A: Swift-BAT refined analysis
  50. GRB 210708A: Swift-XRT refined Analysis
  51. GRB 210708A: Swift detection of a burst
  52. Fermi trigger No 647365516: Global MASTER-Net observations report
  53. Fermi trigger No 647108723: Global MASTER-Net observations report
  54. Fermi trigger No 647120009: Global MASTER-Net observations report
  55. GRB 210702A: iTelescope optical afterglow observations
  56. IceCube-210629A: Upper limits from a search for additional neutrino events in IceCube
  57. IceCube-210629A: One Candidate Counterpart from the Zwicky Transient Facility
  58. IceCube-210629A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  59. Fermi-LAT Gamma-ray Observations of IceCube-210629A
  60. IceCube-210629A - IceCube observation of a high-energy neutrino candidate track-like event
  61. GRB 210626A: GIT optical upper limit
  62. Fermi trigger No 646443989: Global MASTER-Net observations report
  63. Fermi GRB 210627B: Global MASTER-Net observations report
  64. Fermi GRB 210627A: Global MASTER-Net observations report
  65. GRB 210626A: Swift-XRT afterglow detection
  66. Fermi GRB 210626A: Global MASTER-Net observations report
  67. GRB 210626A: Swift/BAT-GUANO detection and arcminute localization
  68. Fermi GRB 210625A: Global MASTER-Net observations report
  69. Fermi trigger No 646189108: Global MASTER-Net observations report
  70. Swift Trigger 1057131: detection of a burst from SGR Swift J1555.2-5402
  71. Fermi trigger No 645857659: Global MASTER-Net observations report
  72. GRB 210619B: Swift detection of a bright burst and optical counterpart
  73. Fermi GRB 210615A: Global MASTER-Net observations report
  74. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  75. Follow-up on HAWC Transient Monitoring Alert J0020+3108
  76. GRB 210610A: SAO RAS optical observations
  77. GRB 210610B: optical observations from Burke-Gaffney Observatory and Abbey Ridge Observatory
  78. Swift-BAT Trigger 1055000: Swift detection of an outburst from 4U 1543-47
  79. GRB 210610A: CrAO/ZTSH optical observations
  80. Fermi trigger No 645047470: Global MASTER-Net observations report
  81. GRB210610A: MeerLICHT multi-colour photometry
  82. Fermi GBM Sub-Threshold Detection of new Swift SGR J1555.2-5402
  83. Fermi trigger No 644449593: Global MASTER-Net observations report
  84. NICER discovery of 3.86 s pulsations from a new magnetar: SGR J1555.2-5402
  85. Swift Detection of probable new Swift SGR J1555.2-5402
  86. MAXI GRB210602.50: Global MASTER-Net observations report
  87. Swift GRB210603.41: Global MASTER-Net observations report
  88. Fermi trigger No 644359567: Global MASTER-Net observations report
  89. Fermi GRB 210529B: Global MASTER-Net observations report
  90. GRB 210528B: DDOTI Upper Limits on the Afterglow
  91. GRB 210528B: MAXI/GSC detection
  92. Fermi GRB 210524A: Global MASTER-Net observations report
  93. GRB 210521A: MAXI/GSC detection
  94. IceCube Alert 210519.86: Global MASTER-Net observations report
  95. IPN triangulation of GRB 210518A
  96. Fermi trigger No 643065622: Global MASTER-Net observations report
  97. Fermi trigger No 642991619: Global MASTER-Net observations report
  98. GRB 210518A: Fermi GBM Final Real-time Localization
  99. GRB 210515C: LCO Optical Upper Limit
  100. Fermi GRB 210515A: Global MASTER-Net observations report

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