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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

3735 results found.

  1. Fermi GRB 220513A: Global MASTER-Net observations report
  2. Konus-Wind detection of GRB 220511A
  3. GRB 220511A: Swift/BAT-GUANO arcminute localization
  4. GRB 220511A: AGILE detection
  5. Fermi trigger No 673846271: Global MASTER-Net observations report
  6. GRB 220506A: MITSuME Akeno optical upper limits
  7. GRB 220506A: GIT optical upper limit.
  8. GRB 220506A: BOOTES-5/JGT optical upper limit
  9. GRB 220506A: Swift-XRT afterglow detection
  10. GRB 220506A: Tiled Swift observations
  11. Swift GRB220506.51: Global MASTER-Net observations report
  12. GRB 220506A/MAXI J1558-266: MAXI/GSC detection
  13. MAXI GRB220506.27: Global MASTER-Net observations report
  14. GRB 220427A: LCO Optical Observations
  15. GRB 220501A: Swift-BAT refined analysis
  16. GRB 220426A: Swift-XRT and UVOT observations
  17. Fermi GRB 220426A: Global MASTER-Net observations report
  18. Fermi GRB 220426B: Global MASTER-Net observations report
  19. Fermi trigger No 672492774: Global MASTER-Net observations report
  20. IceCube Alert 220424.05: Global MASTER-Net observations report
  21. GRB 220421A: Fermi GBM observation
  22. Fermi trigger No 672093919: Global MASTER-Net observations report
  23. IPN triangulation of GRB 220411A
  24. GRB 220408A: Swift-BAT refined analysis
  25. GRB 220408A: 1.3m DFOT Optical upper limit
  26. GRB 220408A: LOAO, DOAO, and, SAO optical upper limit
  27. GRB 220408A: LCO Optical Afterglow Detection
  28. Fermi GRB 220408B: Global MASTER-Net observations report
  29. GRB 220408A: Fermi GBM observation
  30. Fermi-LAT Gamma-ray Observations of IceCube-220405A
  31. IceCube-220405A - IceCube observation of a high-energy neutrino candidate track-like event
  32. Fermi GRB 220401B: Global MASTER-Net observations report
  33. Fermi GRB 220330A: Global MASTER-Net observations report
  34. GRB 220325A: Swift-BAT refined analysis
  35. GRB 220319A: MASTER Global Robotic Net optical observations
  36. GRB 220310A: MITSuME Akeno optical observation
  37. IPN triangulation of GRB 220310A
  38. GRB 220310A: [KAO-Egypt] SDSS r, i observation
  39. Konus-Wind detection of GRB 220310A
  40. GRB 220310A: GIT confirmation of optical afterglow.
  41. GRB 220310A: MASTER optical counterpart detection
  42. GRB 220310A: Swift ToO observations
  43. GRB 220310A: CALET Gamma-Ray Burst Monitor detection
  44. GRB 220310A: MAXI/GSC detection
  45. MAXI GRB220310.02: Global MASTER-Net observations report
  46. Konus-Wind detection of GRB 220308A
  47. Fermi GRB 220309A: Global MASTER-Net observations report
  48. IPN triangulation of GRB 220308A (long / very bright)
  49. IPN triangulation of GRB 220305B
  50. Fermi GRB 220223A: Global MASTER-Net observations report
  51. ZTF22aaajecp/AT2022cmc: Swift Observation and a UV Detection
  52. ZTF22aabjpxh/AT2022cva: NICER X-ray detection is consistent with a GRB afterglow
  53. Fermi GRB 220222A: Global MASTER-Net observations report
  54. ZTF22aabjpxh/AT2022cva: Assy optical observations
  55. ZTF22aaajecb/AT2022cmc: Submillimeter Array detection
  56. IceCube Alert 220221.03: Global MASTER-Net observations report
  57. Konus-Wind observation of GRB 220219A
  58. IPN triangulation of GRB 220219A
  59. IceCube Alert 220220.60: Global MASTER-Net observations report
  60. Fermi trigger No 666962499: Global MASTER-Net observations report
  61. ZTF22aaajecp/AT2022cmc: VLA radio detection
  62. Fermi trigger No 666489765: Global MASTER-Net observations report
  63. GRB 211227A: Konus-Wind detection and joint Konus-Wind+Swift-BAT spectral analysis
  64. IceCube Alert 220202.49: Global MASTER-Net observations report
  65. IPN triangulation of GRB 220128A (long)
  66. GRB 220129A: Fermi GBM Final Real-time Localization
  67. Fermi trigger No 664738369: Global MASTER-Net observations report
  68. GRB 220118A: TARGET optical upper limit
  69. GRB 220117A: Konus-Wind detection and joint Konus-Wind + Swift-BAT spectral analysis
  70. GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
  71. Fermi trigger No 663966693: Global MASTER-Net observations report
  72. IceCube Alert 220115.51: Global MASTER-Net observations report
  73. Fermi trigger No 663927396: Global MASTER-Net observations report
  74. GECAM observations of a series of bursts from SGR J1935+2154
  75. Fermi-GBM Observations of Recent Bursting Activity from SGR J1935+2154
  76. Fermi GRB 220111A: Global MASTER-Net observations report
  77. Fermi trigger No 663274898: Global MASTER-Net observations report
  78. Fermi GRB 220107A: Global MASTER-Net observations report
  79. GRB 220101A: Continued Mondy optical observations
  80. GRB 220101A: TNG NIR afterglow detection
  81. GRB 220101A: Swift-BAT refined analysis
  82. GRB 211227A: Deep early CAHA 2.2m/CAFOS observation
  83. GRB 211227A: CALET Gamma-Ray Burst Monitor detection
  84. GRB 211227A: MAXI/GSC detection
  85. IceCube-20211216B: observations of SN2021gpw in the errorbox of the neutrino trigger
  86. GRB 211225B: Swift-BAT refined analysis
  87. GRB 211225A: MITSuME Akeno optical upper limits
  88. MAXI GRB211225.14: Global MASTER-Net observations report
  89. GRB 211225A/MAXI J0827-071: MAXI/GSC detection
  90. Fermi trigger No 662084433: Global MASTER-Net observations report
  91. GRB 211218A: MITSuME Akeno optical upper limits
  92. Fermi GRB 211219B: Global MASTER-Net observations report
  93. GRB 211218A, MAXI J0909-041: MAXI/GSC detection
  94. MAXI GRB211218.04: Global MASTER-Net observations report
  95. Fermi GRB 211216A: Global MASTER-Net observations report
  96. GRB 211211A: LCO Optical Observations
  97. Fermi GRB 211211B: Global MASTER-Net observations report
  98. IceCube-211208A: No significant detection in HAWC
  99. Fermi trigger No 660736561: Global MASTER-Net observations report
  100. GRB 211204C: AstroSat CZTI detection

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