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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"

5182 results found.

  1. GRB 230322B: Swift-XRT refined Analysis
  2. Fermi trigger No 701071944: Global MASTER-Net observations report
  3. Fermi trigger No 701058254: Global MASTER-Net observations report
  4. GRB 230321B: AstroSat CZTI detection
  5. GRB 230314A: TURBO Optical Upper Limit
  6. Trigger 1160641: Swift detection of 4U 1630-472 (a.k.a. SWIFT J1633.8-4724A)
  7. IPN triangulation of GRB 230304B
  8. GRB 230314A: Fermi GBM Final Real-time Localization
  9. Further improved IPN localization for GRB 230307A
  10. Triggers 1159434, 1159435 and 1159437: Swift detection of Sco X-1 due to Star Tracker loss of lock
  11. Trigger 1159327: Swift detection of SGR1806-20
  12. IceCube Alert 230306.46: Global MASTER-Net observations report
  13. Fermi trigger No 699294715: Global MASTER-Net observations report
  14. GRB 230228A: Swift-XRT refined Analysis
  15. Fermi GRB 230227A: Global MASTER-Net observations report
  16. Fermi trigger No 699029364: Global MASTER-Net observations report
  17. GRB 230217A: Gemini-South Optical Observation
  18. GRB 230220A: MAXI/GSC detection
  19. IceCube Alert 230217.87: Global MASTER-Net observations report
  20. GRB 230216A: Swift-XRT refined Analysis
  21. Fermi trigger No 697678542: Global MASTER-Net observations report
  22. Fermi GRB 230207A: Global MASTER-Net observations report
  23. GRB 230204B: LCOGT Optical Upper Limits
  24. GRB 230205A: Swift-XRT refined Analysis
  25. GRB 230204B: MAXI/GSC detection
  26. GRB 230204A: Swift-XRT refined Analysis
  27. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  28. Fermi trigger No 697208885: Global MASTER-Net observations report
  29. Fermi trigger No 697098930: Global MASTER-Net observations report
  30. Fermi GRB 230201B: Global MASTER-Net observations report
  31. GRB 230124A: Fermi GBM Observation
  32. GRB 230123A: LCOGT Optical Upper Limits
  33. Fermi GRB 230124A: Global MASTER-Net observations report
  34. GRB 230124A: Fermi GBM Final Real-time Localization
  35. GRB 230122A: Swift/BAT-GUANO detection
  36. GRB 230123A: Swift-XRT refined Analysis
  37. GRB 230116D: LCOGT Optical Upper Limit
  38. GRB 230116D: Swift-XRT refined Analysis
  39. Fermi GRB 230117A: Global MASTER-Net observations report
  40. GRB 230116D: Swift detection of a burst
  41. Fermi GRB 230112A: Global MASTER-Net observations report
  42. IceCube-221223A: JCMT/SCUBA2 observations
  43. GRB 221231A: Swift-XRT observations
  44. IceCube-221223A: No Candidate Counterparts from the Zwicky Transient Facility
  45. IceCube-221224A: Upper limits from a search for additional neutrino events in IceCube
  46. IceCube-221223A: Upper limits from a search for additional neutrino events in IceCube
  47. GRB 221226B: Swift-XRT refined Analysis
  48. Fermi-LAT gamma-ray observations of IceCube-221224A
  49. IceCube-221224A: BOOTES-4/MET Optical Upper Limit
  50. Fermi GRB 221223A: Global MASTER-Net observations report
  51. IceCube Alert 221224.04: Global MASTER-Net observations report
  52. IceCube-221224A - IceCube observation of a high-energy neutrino candidate track-like event
  53. GRB 221218A: MITSuME Akeno optical upper limits
  54. GRB 221216A: Swift-XRT refined Analysis
  55. GRB 221216A: Swift detection of a burst
  56. IPN triangulation of GRB 221209A (long)
  57. Fermi trigger No 692713692: Global MASTER-Net observations report
  58. Swift Trigger 1144538 is not a GRB
  59. Fermi trigger No 692607435: Global MASTER-Net observations report
  60. Fermi GRB 221211A: Global MASTER-Net observations report
  61. GRB 221209A: BALROG localization (Fermi Trigger 692257829 / GRB 221209243)
  62. GRB 221209A: Fermi GBM Final Real-time Localization
  63. GRB 221206C: Fermi GBM Final Real-time Localization
  64. GRB 221201A: Fermi GBM observation
  65. GRB 221202A: Swift-XRT refined Analysis
  66. GRB 221201A: Swift-XRT refined Analysis
  67. GRB 221201A: Fermi GBM Final Real-time Localization
  68. IceCube-221124A: Upper limits from a search for additional neutrino events in IceCube
  69. IceCube-221124A: BOOTES-4/MET and BOOTES-2/TELMA optical upper limit
  70. IPN triangulation of GRB 221124A (long)
  71. GRB 221124A: Swift/BAT-GUANO detection
  72. Fermi-LAT gamma-ray observations of IceCube-221124A
  73. GRB 221124A: CALET Gamma-Ray Burst Monitor detection
  74. IceCube-221124A - IceCube observation of a high-energy neutrino candidate track-like event
  75. IceCube Alert 221124.66: Global MASTER-Net observations report
  76. GRB 221120A: Swift-XRT refined Analysis
  77. GRB 221110A: Swift-XRT refined Analysis
  78. GRB 221107A: Fermi GBM Final Localization
  79. GRB 221028A: Swift-XRT refined Analysis
  80. GRB 221028A: MITSuME Okayama optical upper limits
  81. GRB 221028B: MAXI/GSC detection
  82. GRB 221028A: BOOTES-4/MET optical upper limit
  83. GRB 221027B: Swift-XRT refined Analysis
  84. Konus-Wind detection of GRB 221022B
  85. IPN triangulation of GRB 221022B (long)
  86. LAT GRB221025.04: Global MASTER-Net observations report
  87. GRB 221022B: Fermi GBM Final Real-time Localization
  88. Improved IPN localization for GRB 221009A (BepiColombo-MGNS light curve)
  89. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  90. IPN triangulation of GRB 221017A (long)
  91. GRB 221016A: Swift-XRT refined Analysis
  92. GRB 221017A: MAXI/GSC detection
  93. GRB 221016A: Swift detection of a burst
  94. Konus-Wind observation of the recent SGR 1935+2154 activity
  95. Fermi Gamma-ray Burst Monitor detections of SGR 1935+2154
  96. GRB221009A: RTT-150 optical observations
  97. Fermi trigger No 687345829: Global MASTER-Net observations report
  98. Fermi trigger No 687344475: Global MASTER-Net observations report
  99. Fermi trigger No 687340841: Global MASTER-Net observations report
  100. Fermi trigger No 687337536: Global MASTER-Net observations report

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