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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"

12169 results found.

  1. EP260110a: NOT and GTC Optical and Near-Infrared Observations
  2. Konus-Wind detection of GRB 260101A
  3. GRB 260112B: Fermi GBM Final Real-time Localization
  4. IceCube-260111A - IceCube observation of a high-energy neutrino candidate track-like event
  5. IceCube Alert 260111A: Global MASTER-Net observations report
  6. EP260110a: refined analysis of the EP-WXT and EP-FXT observations
  7. EP260110a: SVOM/C-GFT upper limit
  8. EP260110a: BOOTES-5/JGU optical upper limit
  9. EP260110a: Einstein Probe detection of an X-ray transient
  10. Fermi GRB 260107A: Global MASTER-Net observations report
  11. EP260105b/EP-WXT trigger 01709251028: Einstein Probe detection of an X-ray transient
  12. EP260105a: refined analysis of the EP-WXT and EP-FXT observations
  13. EP260104a: Einstein Probe detection of a fast X-ray transient
  14. EP260105a: Einstein Probe detection of an X-ray transient
  15. Fermi GRB 260104B: Global MASTER-Net observations report
  16. GRB 260104A: Swift-XRT refined Analysis
  17. GRB 260104A: Swift detection of a burst
  18. Fermi-LAT Gamma-ray Observations of IceCube-251225A
  19. SVOM GRB260103.08: Global MASTER-Net observations report
  20. EP260101a: Einstein Probe detection of an X-ray transient
  21. GRB 251230A/EP251230a: Optical upper limit with Kinder observations
  22. EP251229a: Optical upper limit with Kinder observations
  23. GRB 251230A: Swift-XRT refined Analysis
  24. EP251230a / GRB 251230A: refined analysis of the EP-WXT and EP-FXT observations
  25. GRB 251230A: Swift/UVOT detection
  26. GRB251230A: 7DT optical upper limits
  27. GRB 251230A / EP251230a: NOT observations and spectroscopic redshift upper limit z < 2.2
  28. EP251229a: BOOTES-2 early optical upper limit
  29. GRB 251230A / EP251230a: SVOM/VT optical observation
  30. EP251229a: refined analysis of the EP-WXT and EP-FXT observations
  31. EP251230a / GRB 251230A: Einstein Probe detection of an X-ray transient
  32. EP251229a: Global MASTER-Net observations report
  33. EP251229a: Einstein Probe detection of an X-ray transient
  34. GRB 251230A: Swift detection of a burst with a bright optical counterpart
  35. Fermi GRB 251228A: Global MASTER-Net observations report
  36. SVOM GRB251227.07: Global MASTER-Net observations report
  37. IceCube-251225A: Upper limits from a search for additional neutrino events in IceCube
  38. IceCube-251225A - IceCube observation of a high-energy neutrino candidate track-like event
  39. GRB 251222A/EP251222b: Optical detection with Kinder observations
  40. EP251222a: Optical upper limit with Kinder observations
  41. GRB 251205A: Kilonova-Catcher optical afterglow detection
  42. EP251220a: CrAO ZTSh optical observations
  43. EP251222a: refined analysis of the EP-WXT and EP-FXT observations
  44. Konus-Wind detection of GRB 251222A / EP251222b
  45. GRB 251222A: Swift-XRT afterglow detection
  46. GRB 251222A: 1.3m DFOT optical detection
  47. GRB251221A: 7DT optical upper limits
  48. EP251222b/GRB 251222A: SVOM/GRM observation
  49. EP251222a: Einstein Probe detection of an X-ray transient
  50. EP251221a: Einstein Probe detection of a fast X-ray transient
  51. EP251220a: EP-FXT follow-up observation
  52. EP 251220a: GOTO optical counterpart detection
  53. Swift GRB251221A: Global MASTER-Net observations report
  54. EP251220a: Global MASTER-Net observations report
  55. EP251220a: EP detection of a fast X-ray transient
  56. SVOM GRB251220.98: Global MASTER-Net observations report
  57. GRB 251220B: Fermi GBM Final Real-time Localization
  58. GRB 251219A: GECAM-B detection of a possible magnetar X-ray burst from SGR 1830-0645
  59. Fermi-LAT Gamma-ray Observations of IceCube-251218A
  60. GRB 251220A: MAXI/GSC detection
  61. IceCube-251218A: Upper limits from a search for additional neutrino events in IceCube
  62. SVOM GRB251219.11: Global MASTER-Net observations report
  63. IceCube-251218A - IceCube observation of a high-energy neutrino candidate track-like event
  64. IceCube Alert 251218.85: Global MASTER-Net observations report
  65. Fermi GRB 251217A: Global MASTER-Net observations report
  66. Fermi GRB 251215A: Global MASTER-Net observations report
  67. EP251214a: Optical upper limit with Kinder observations
  68. EP251214b : Einstein Probe detection of a fast X-ray transient
  69. EP251214b : Einstein Probe detection of a fast X-ray transient
  70. EP251214b (EP trigger 01709250023): LCO optical limits
  71. GRB 251203B: AbAO optical observations
  72. GRB 251214B: Swift-XRT refined Analysis
  73. GRB 251214D: AstroSat CZTI detection of a long burst
  74. GRB 251213A: AstroSat CZTI detection
  75. GRB 251214A: AstroSat CZTI detection
  76. GRB 251214B : MASTER optical afterglow detection
  77. Swift GRB 251214B: Global MASTER-Net observations report
  78. GRB 251214B: Swift detection of a burst with an optical counterpart
  79. EP251214a: EP-WXT detection of an X-ray transient possibly associated with GRB 251214A
  80. EP251212a: Global MASTER-Net observations report
  81. EP251212a / GRB 251212A: AstroSat CZTI detection
  82. GRB 251211B: AstroSat CZTI detection
  83. Fermi-LAT Gamma-ray Observations of IceCube-251210A
  84. Fermi GRB 251211B: Global MASTER-Net observations report
  85. GRB 251211B: Fermi GBM Final Real-time Localization
  86. GRB 251209A: AstroSat CZTI detection
  87. GRB 251129A/EP251129a: AbAO and Mondy optical observations
  88. EP251130a: Mondy and AbAO optical observations
  89. GRB 251208A: AstroSat CZTI detection
  90. GRB 251208B: Swift-XRT afterglow detection
  91. GRB 251208B: Fermi GBM Observation
  92. GRB 251208D: Swift-XRT observations
  93. GRB 251208B: Fermi-LAT detection
  94. GRB 251206A: SVOM detection of a burst through offline search
  95. GRB 251205A: Swift-XRT refined Analysis
  96. Konus-Wind detection of GRB 251118A
  97. Swift GRB251205A: Global MASTER-Net observations report
  98. GRB 251203A: SVOM/GRM observation
  99. GRB 251203A: AstroSat CZTI detection
  100. GRB 251203C: EP-FXT follow-up observation

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