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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"

28120 results found.

  1. GRB 220118A: GIT optical observations
  2. GRB 220118A: Enhanced Swift-XRT position
  3. GRB 220118A: MITSuME Akeno optical observation
  4. GRB 220117B: z-band limit
  5. GRB 220118A: Swift detection of a burst with an optical counterpart
  6. GRB 220117A: MITSuME Akeno optical upper limits
  7. Fermi GBM Sub-Threshold Detection of GRB 220117A
  8. GRB 220117B: Swift-BAT refined analysis
  9. GRB 220117A: Swift-BAT refined analysis
  10. IceCube-220115A: Upper limits from a search for additional neutrino events in IceCube
  11. GRB 220117B: Swift/UVOT Upper Limits
  12. GRB 220117A: Swift/UVOT Upper Limits
  13. GRB 220117A: LCO Optical Observations
  14. GRB 220117A: VLT/X-shooter optical afterglow and redshift
  15. Fermi-LAT Gamma-ray Observations of IceCube-220115A and detection of a new gamma-ray source, Fermi J2350.2+2620
  16. GRB 220117B: Swift-XRT refined Analysis
  17. GRB 220117A: Swift-XRT refined Analysis
  18. AMON IC_HAWC NuEm-220116A: No neutrino counterpart detected with ANTARES
  19. GRB 220117B: Nanshan/NEXT optical upper limit
  20. GRB 220117B: MITSuME Akeno optical upper limits
  21. GRB 220117B: Enhanced Swift-XRT position
  22. GRB 220117A: Enhanced Swift-XRT position
  23. GRB 220117B: Swift detection of a burst
  24. GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
  25. GRB 220117A: Swift detection of a burst
  26. GRB 220101A: The most powerful GRB and BDHN I in 26 years
  27. Fermi trigger No 663899819: Global MASTER-Net observations report
  28. Fermi trigger No 663886592: Global MASTER-Net observations report
  29. GRB 220111A: AstroSat CZTI detection
  30. GRB 220111A: BALROG localization (Fermi Trigger 663621714 / GRB 220111807)
  31. GRB 220107A: SAO RAS optical observations
  32. GRB 220107A: further SAO RAS optical observations
  33. GRB 220101A: Additional Liverpool telescope photometry
  34. GRB 220107A: SAO RAS optical observations
  35. GRB 220108A: Swift/BAT-GUANO detection outside the coded FOV
  36. GRB 220107A: AbAO and Terskol optical observations
  37. GRB 220107B: MITSuME Akeno optical upper limits
  38. GRB 220107B: Nanshan/NEXT optical upper limits and host galaxy candidate
  39. GRB 220107A: Nanshan/NEXT optical observations
  40. GRB 220107A: Swift/UVOT Detection
  41. GRB 220107B: Fermi GBM observations
  42. GRB 220107A: MITSuME Akeno optical observation
  43. GRB 220107B: AstroSat CZTI detection
  44. GRB 220107B: Swift-XRT afterglow detection
  45. GRB 220107A: Swift-XRT afterglow detection
  46. GRB 220107A: AstroSat CZTI detection
  47. GRB 220107A: Fermi GBM observations
  48. Fermi trigger No 663274898: Global MASTER-Net observations report
  49. GRB 220107A: Swift/BAT-GUANO arcminute localization
  50. GRB 220101A: Tautenburg observations
  51. GRB 220107A: BALROG localization (Fermi Trigger 663259536 / GRB 220107615)
  52. GECAM observation of a burst from SGR J1555.2-5402
  53. GECAM detection of a short burst from SGR 1935+2154
  54. GRB 220101A: further TNG NIR observations
  55. GRB 220101A: 3rd LCO Optical Observation
  56. GRB 220101A: 2.2m CAHA (+CAFOS) first day optical detection
  57. GRB 220101A: iTelescope optical observations
  58. GRB 211227A: Lijiang 2.4m Telescope Optical Observations
  59. GRB 220101A: LCO Continued Optical Observations
  60. GRB 220104A：GECAM detection
  61. GRB 211229B: Fermi GBM observation
  62. GRB 211227A: Gemini South Optical Observations
  63. GRB 211229B: Swift/BAT-GUANO detection outside the coded FOV
  64. Alert from the HAWC Burst Monitor HAWC-220103A
  65. GRB 220101A: TNG NIR afterglow detection
  66. GRB 220101A: LCO Optical Observations
  67. GRB 220101A: Tautenburg observations
  68. GRB 220101A: Swift-BAT refined analysis
  69. GRB 220101A: GMG observation (2nd epoch)
  70. GRB 211231A: AstroSat CZTI detection
  71. GRB 220101A: OASDG optical observations
  72. GRB 220101A: GMG observation
  73. GRB220101A: optical afterglow detection from Konkoly Observatory
  74. GRB 220101A: Fermi GBM Detection
  75. GRB 220101A: Liverpool telescope imaging of a high-redshift afterglow
  76. GRB 220101A: Swift-XRT refined Analysis
  77. GRB 220101A: Xinglong-2.16m photometry and spectroscopy
  78. GRB 220101: Swift/UVOT Detection
  79. GRB 220101A: Enhanced Swift-XRT position
  80. GRB 220101A: Swift detection of a burst with a bright optical counterpart
  81. IPN triangulation of GRB 211219A
  82. GRB 211231A: GECAM detection
  83. GRB 211229A: Swift-XRT and UVOT observations
  84. GRB 211229A: Fermi GBM observation
  85. GRB 211229C: Swift/BAT-GUANO detection likely outside the coded FOV
  86. GRB 211229A: Swift/BAT-GUANO arcminute localization
  87. GRB 211229A: GECAM detection
  88. GRB 211227A: Swift/UVOT Upper Limits
  89. GRB 211227A: Swift-XRT refined Analysis
  90. GRB 211227A: Swift-BAT refined analysis
  91. Konus-Wind detection of the intermediate flare from SGR 1935+2154
  92. GRB 211227A: Liverpool Telescope upper limits
  93. GRB 211227A: Enhanced Swift-XRT position
  94. GRB 211227A: LCO Optical Observations
  95. GRB 211227A: Nanshan/NEXT optical observations and host galaxy candidate
  96. GRB 211227A: MAXI/GSC detection
  97. GRB 211221A: Swift/UVOT Upper Limits
  98. GRB 211227A: Swift detection of a burst
  99. GRB 211226A: Swift/BAT-GUANO detection outside the coded FOV
  100. GRB 211225B: Swift-BAT refined analysis

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