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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"

37700 results found.

  1. GRB 260120B: Fermi GBM Observation
  2. GRB 260120B: Swift/UVOT Detection
  3. GRB 260120B: COLIBRÍ optical upper limits
  4. GRB 260120B: Enhanced Swift-XRT position
  5. GRB 260120B: SVOM/C-GFT optical counterpart detection
  6. GRB 260120C: Fermi GBM Final Real-time Localization
  7. GRB 260101A: 239Alferov CubeSat detection
  8. GRB 260120B: Swift detection of a burst
  9. GRB 260120B: Fermi GBM Final Real-time Localization
  10. EP260119A: Mondy I-Band Observations
  11. Fermi trigger No 790601190: Global MASTER-Net observations report
  12. Fermi trigger No 790570272: Global MASTER-Net observations report
  13. GRB 260114A: Swift/UVOT Upper Limits
  14. GRB 251202A: further radio observations with the VLA
  15. EP260119a: KAIT optical observations
  16. GRB 260120A: Fermi GBM Final Real-time Localization
  17. EP260119a: SAO RAS optical observations
  18. GRB 251208D: SVOM/ECLAIRs refined analysis
  19. GRB 251208D: SVOM/ECLAIRs refined analysis
  20. GRB 260117A: Swift-XRT afterglow detection
  21. GRB 260115A: AstroSat CZTI detection
  22. GRB 260117A: ZTSh optical upper limit
  23. GRB 260110A: SVOM detection of a burst through offline search
  24. GRB 260117A: SVOM/COLIBRÍ (FM-GFT) optical observations
  25. Fermi-LAT Gamma-ray Observations of IceCube-260115A
  26. GRB 260117A: SVOM/VT optical candidate
  27. GRB 260117A: SVOM/C-GFT upper limit
  28. GRB 260117A: Swift-XRT observations
  29. GRB 260117A: Swift ToO observations
  30. GRB 260117A: SVOM detection of a long faint burst
  31. GRB 260115A: GECAM-B observation
  32. GRB 260114A: VLT/MUSE spectroscopic observations
  33. GRB 260111A: COLIBRÍ fading of the optical counterpart candidate
  34. GRB 260114A: VLT/HAWK-I further near-infrared upper limits
  35. IceCube-260115A - IceCube observation of a high-energy neutrino candidate track-like event
  36. GRB 260115A: BALROG localization (Fermi Trigger 790192010 / GRB 260115741)
  37. Fermi GRB 260115A: Global MASTER-Net observations report
  38. GRB 260115A: Fermi GBM Final Real-time Localization
  39. GRB260114A: STEP/T80S optical limits
  40. GRB 251222A: radio detection with the VLA
  41. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  42. Konus-Wind detection of GRB 260114A
  43. GRB 260114A: Swift-XRT refined Analysis
  44. GRB 260114A: 6 GHz VLA observations
  45. GRB 260114A: VLT/X-shooter redshift of the putative host galaxy
  46. GRB 260114A : MITSuME Akeno optical upper limits
  47. GRB 260114A: COLIBRÍ optical upper limits
  48. GRB 260114A: TNG NIR upper limit
  49. GRB 260114A: NOT optical observations
  50. Konus-Wind detection of GRB 251230A / EP251230a
  51. GRB 260114A: SVOM/GRM observation of a short burst
  52. Swift GRB 260114A: Global MASTER-Net observations report
  53. GRB 260114A: GECAM-B observation of a short burst
  54. GRB 260114A: Mondy optical observations
  55. GRB 260114A: Fermi GBM observation
  56. GRB 260112B: GECAM-B observation
  57. GRB 260114A: GMG Optical Observation
  58. Fermi-LAT Gamma-ray Observations of IceCube-260111A
  59. GRB 260114A: Swift detection of a short burst
  60. GRB 260114A: Fermi GBM Final Real-time Localization
  61. Konus-Wind detection of GRB 260101A
  62. GRB 260111A: Swift-XRT observations
  63. Swift Trigger 1439093: is probably not GRB 260113A
  64. GRB 260111A: COLIBRÍ optical afterglow candidate
  65. GRB 260111A: GECAM-B observation of a burst
  66. GRB 260111A: Fermi GBM Observation
  67. Swift Trigger 1434591 is not a GRB
  68. GRB 260111A: GOTO optical upper limits
  69. GRB 260112B: Fermi GBM Final Real-time Localization
  70. GRB 260111A: Swift ToO observations
  71. GRB 251230A: Mondy Optical Observations
  72. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  73. GRB 260112A: Fermi GBM Final Real-time Localization
  74. IceCube-260111A - IceCube observation of a high-energy neutrino candidate track-like event
  75. Fermi GRB 260111A: Global MASTER-Net observations report
  76. GRB 260111A: Fermi GBM Final Real-time Localization
  77. EP260110a: KAIT optical upper limit
  78. GRB 260109C: LCO optical upper limits
  79. GRB 260109C: Kilonova-Catcher optical upper limit
  80. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  81. Swift Trigger 1434591: possible GRB 260109C
  82. GRB 260109B: Fermi GBM Final Real-time Localization
  83. GRB 260102A: Swift-XRT afterglow detection
  84. GRB 260109A: Fermi GBM Final Real-time Localization
  85. GRB 260104A: Swift-BAT refined analysis
  86. GRB 260101A: Swift-BAT refined analysis
  87. Swift GRB 251230A: Global MASTER-Net OT detection
  88. Fermi GRB 260107A: Global MASTER-Net observations report
  89. GRB 260102A: AbAO optical observations
  90. GRB 260107A: Fermi GBM Final Real-time Localization
  91. Fermi GRB 260105A: Global MASTER-Net observations report
  92. GRB 260105B: Fermi GBM Detection
  93. GRB 260105B: BALROG localization (Fermi Trigger 789348101 / GRB 260105973)
  94. GRB 260105A: SVOM/GRM observation
  95. GRB 260105B: SVOM/GRM observation
  96. Fermi GRB 260105B: Global MASTER-Net observations report
  97. GRB 260105B: Fermi GBM Final Real-time Localization
  98. GRB 260105A: Fermi GBM Final Real-time Localization
  99. GRB 260101A: COLIBRÍ optical upper limits
  100. GRB 260103A: Insight-HXMT/HE detection

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