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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"

5177 results found.

  1. Trigger 1160641: Swift detection of 4U 1630-472 (a.k.a. SWIFT J1633.8-4724A)
  2. IPN triangulation of GRB 230304B
  3. GRB 230314A: Fermi GBM Final Real-time Localization
  4. Further improved IPN localization for GRB 230307A
  5. Triggers 1159434, 1159435 and 1159437: Swift detection of Sco X-1 due to Star Tracker loss of lock
  6. Trigger 1159327: Swift detection of SGR1806-20
  7. IceCube Alert 230306.46: Global MASTER-Net observations report
  8. Fermi trigger No 699294715: Global MASTER-Net observations report
  9. GRB 230228A: Swift-XRT refined Analysis
  10. Fermi GRB 230227A: Global MASTER-Net observations report
  11. Fermi trigger No 699029364: Global MASTER-Net observations report
  12. GRB 230217A: Gemini-South Optical Observation
  13. GRB 230220A: MAXI/GSC detection
  14. IceCube Alert 230217.87: Global MASTER-Net observations report
  15. GRB 230216A: Swift-XRT refined Analysis
  16. Fermi trigger No 697678542: Global MASTER-Net observations report
  17. Fermi GRB 230207A: Global MASTER-Net observations report
  18. GRB 230204B: LCOGT Optical Upper Limits
  19. GRB 230205A: Swift-XRT refined Analysis
  20. GRB 230204B: MAXI/GSC detection
  21. GRB 230204A: Swift-XRT refined Analysis
  22. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  23. Fermi trigger No 697208885: Global MASTER-Net observations report
  24. Fermi trigger No 697098930: Global MASTER-Net observations report
  25. Fermi GRB 230201B: Global MASTER-Net observations report
  26. GRB 230124A: Fermi GBM Observation
  27. GRB 230123A: LCOGT Optical Upper Limits
  28. Fermi GRB 230124A: Global MASTER-Net observations report
  29. GRB 230124A: Fermi GBM Final Real-time Localization
  30. GRB 230122A: Swift/BAT-GUANO detection
  31. GRB 230123A: Swift-XRT refined Analysis
  32. GRB 230116D: LCOGT Optical Upper Limit
  33. GRB 230116D: Swift-XRT refined Analysis
  34. Fermi GRB 230117A: Global MASTER-Net observations report
  35. GRB 230116D: Swift detection of a burst
  36. Fermi GRB 230112A: Global MASTER-Net observations report
  37. IceCube-221223A: JCMT/SCUBA2 observations
  38. GRB 221231A: Swift-XRT observations
  39. IceCube-221223A: No Candidate Counterparts from the Zwicky Transient Facility
  40. IceCube-221224A: Upper limits from a search for additional neutrino events in IceCube
  41. IceCube-221223A: Upper limits from a search for additional neutrino events in IceCube
  42. GRB 221226B: Swift-XRT refined Analysis
  43. Fermi-LAT gamma-ray observations of IceCube-221224A
  44. IceCube-221224A: BOOTES-4/MET Optical Upper Limit
  45. Fermi GRB 221223A: Global MASTER-Net observations report
  46. IceCube Alert 221224.04: Global MASTER-Net observations report
  47. IceCube-221224A - IceCube observation of a high-energy neutrino candidate track-like event
  48. GRB 221218A: MITSuME Akeno optical upper limits
  49. GRB 221216A: Swift-XRT refined Analysis
  50. GRB 221216A: Swift detection of a burst
  51. IPN triangulation of GRB 221209A (long)
  52. Fermi trigger No 692713692: Global MASTER-Net observations report
  53. Swift Trigger 1144538 is not a GRB
  54. Fermi trigger No 692607435: Global MASTER-Net observations report
  55. Fermi GRB 221211A: Global MASTER-Net observations report
  56. GRB 221209A: BALROG localization (Fermi Trigger 692257829 / GRB 221209243)
  57. GRB 221209A: Fermi GBM Final Real-time Localization
  58. GRB 221206C: Fermi GBM Final Real-time Localization
  59. GRB 221201A: Fermi GBM observation
  60. GRB 221202A: Swift-XRT refined Analysis
  61. GRB 221201A: Swift-XRT refined Analysis
  62. GRB 221201A: Fermi GBM Final Real-time Localization
  63. IceCube-221124A: Upper limits from a search for additional neutrino events in IceCube
  64. IceCube-221124A: BOOTES-4/MET and BOOTES-2/TELMA optical upper limit
  65. IPN triangulation of GRB 221124A (long)
  66. GRB 221124A: Swift/BAT-GUANO detection
  67. Fermi-LAT gamma-ray observations of IceCube-221124A
  68. GRB 221124A: CALET Gamma-Ray Burst Monitor detection
  69. IceCube-221124A - IceCube observation of a high-energy neutrino candidate track-like event
  70. IceCube Alert 221124.66: Global MASTER-Net observations report
  71. GRB 221120A: Swift-XRT refined Analysis
  72. GRB 221110A: Swift-XRT refined Analysis
  73. GRB 221107A: Fermi GBM Final Localization
  74. GRB 221028A: Swift-XRT refined Analysis
  75. GRB 221028A: MITSuME Okayama optical upper limits
  76. GRB 221028B: MAXI/GSC detection
  77. GRB 221028A: BOOTES-4/MET optical upper limit
  78. GRB 221027B: Swift-XRT refined Analysis
  79. Konus-Wind detection of GRB 221022B
  80. IPN triangulation of GRB 221022B (long)
  81. LAT GRB221025.04: Global MASTER-Net observations report
  82. GRB 221022B: Fermi GBM Final Real-time Localization
  83. Improved IPN localization for GRB 221009A (BepiColombo-MGNS light curve)
  84. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  85. IPN triangulation of GRB 221017A (long)
  86. GRB 221016A: Swift-XRT refined Analysis
  87. GRB 221017A: MAXI/GSC detection
  88. GRB 221016A: Swift detection of a burst
  89. Konus-Wind observation of the recent SGR 1935+2154 activity
  90. Fermi Gamma-ray Burst Monitor detections of SGR 1935+2154
  91. GRB221009A: RTT-150 optical observations
  92. Fermi trigger No 687345829: Global MASTER-Net observations report
  93. Fermi trigger No 687344475: Global MASTER-Net observations report
  94. Fermi trigger No 687340841: Global MASTER-Net observations report
  95. Fermi trigger No 687337536: Global MASTER-Net observations report
  96. GRB 221009A: MITSuME Okayama optical observation
  97. Fermi trigger No 687281393: Global MASTER-Net observations report
  98. GRB221009A: optical afterglow measurements from Konkoly Observatory
  99. Fermi trigger No 687205006: Global MASTER-Net observations report
  100. GRB 221009A: Sintez-Newton/CrAO optical observations

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