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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"

3533 results found.

  1. GRB 220606B: Fermi GBM Final Real-time Localization
  2. Fermi trigger No 675992935: Global MASTER-Net observations report
  3. GRB 220527A: MITSuME Akeno continued optical observation
  4. GRB 220527A: Lick 3m Optical Observations
  5. GRB 220528A: Fermi GBM Observation
  6. Fermi GRB 220530A: Global MASTER-Net observations report
  7. GRB 220528A: Fermi GBM Final Localization
  8. GRB 220527A: REM optical/NIR observations
  9. GRB 220527A: VLT/X-shooter spectroscopic redshift
  10. Fermi trigger No 675411172: Global MASTER-Net observations report
  11. GRB 220527A: NOT optical photometry and spectroscopic redshift
  12. IPN triangulation of GRB 220522B
  13. GRB 220521A: ISON-Castelgrande observatory optical observations
  14. IPN triangulation of GRB 220519A
  15. Konus-Wind detection of GRB 220506A
  16. GRB 220514B: MAXI/GSC detection
  17. IceCube-220513A: No Candidate Counterparts from the Zwicky Transient Facility
  18. IceCube Alert 220513.97: Global MASTER-Net observations report
  19. Fermi GRB 220513A: Global MASTER-Net observations report
  20. GRB 220506A: MITSuME Akeno optical upper limits
  21. IceCube Alert 220509.76: Global MASTER-Net observations report
  22. GRB 220506A/MAXI J1558-266: MAXI/GSC detection
  23. IceCube-220421A: Upper limits from a search for additional neutrino events in IceCube
  24. GRB 220423A: Detection by VZLUSAT-2
  25. Fermi GRB 220426B: Global MASTER-Net observations report
  26. Fermi trigger No 672374264: Global MASTER-Net observations report
  27. Fermi trigger No 671729344: Global MASTER-Net observations report
  28. Konus-Wind detection of GRB 220412B
  29. GRB 220408B: Fermi GBM observation
  30. Konus-Wind detection of GRB 220408B
  31. GRB 220412A: Continued RATIR Observations and Steepening of the Light Curve
  32. GRB 220408B: Fermi-LAT detection
  33. GRB 220412B: MITSuME Akeno optical upper limits
  34. IPN triangulation of GRB 220408B
  35. Fermi GRB 220411A: Global MASTER-Net observations report
  36. GRB 220408B: AstroSat CZTI detection
  37. GRB 220408A: BOOTES-5/JGT optical afterglow detection
  38. Fermi GRB 220408B: Global MASTER-Net observations report
  39. GRB 220408B: Fermi GBM Final Localization
  40. IceCube Alert 220405.93: Global MASTER-Net observations report
  41. IceCube Alert 220405.21: Global MASTER-Net observations report
  42. GRB 220403B: Fermi GBM detection
  43. GRB 220404A: Swift detection of a burst
  44. Swift GRB 220403B: Global MASTER-Net observations report
  45. Fermi GRB 220403A: Global MASTER-Net observations report
  46. Fermi GRB 220401B: Global MASTER-Net observations report
  47. Fermi trigger No 670501065: Global MASTER-Net observations report
  48. GRB 220330A: Fermi GBM Final Real-time Localization
  49. ZTF22aaajecp/AT2022cmc: 1.3m DFOT Optical observations
  50. GRB 220324A: AstroSat CZTI detection
  51. IPN triangulation of GRB 220310A
  52. Konus-Wind detection of GRB 220310A
  53. MAXI GRB220310.02: Global MASTER-Net observations report
  54. Fermi GRB 220309A: Global MASTER-Net observations report
  55. GRB 220304A Fermi GBM detection
  56. Fermi GRB 220306A: Global MASTER-Net observations report
  57. GRB 220304A: Swift/BAT-GUANO detection outside the coded FOV
  58. GRB 220304A: BALROG localization (Fermi Trigger / GRB 220304228)
  59. GRB 220304A: Fermi GBM Final Real-time Localization
  60. GRB 220228A: Fermi GBM observation
  61. GRB 220228A: Fermi-LAT detection
  62. GRB 220228A: Fermi GBM Final Localization
  63. Fermi trigger No 667737010: Global MASTER-Net observations report
  64. IceCube Alert 220220.60: Global MASTER-Net observations report
  65. Fermi trigger No 666962499: Global MASTER-Net observations report
  66. GRB 220218A: Swift detection of a burst
  67. Fermi trigger No 666489765: Global MASTER-Net observations report
  68. GRB 220211B: Fermi GBM Final Real-time Localization
  69. Konus-Wind detection of GRB 220130A
  70. GRB 220128A: AstroSat CZTI detection
  71. GRB 220131A: Fermi GBM Final Real-time Localization
  72. GRB 220117A: VLT/X-shooter optical afterglow and redshift
  73. GRB 220117B: Swift detection of a burst
  74. GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
  75. Fermi trigger No 663966693: Global MASTER-Net observations report
  76. Fermi-GBM Observations of Recent Bursting Activity from SGR J1935+2154
  77. Fermi GRB 220111A: Global MASTER-Net observations report
  78. Konus-Wind detection of GRB 220101A
  79. Fermi trigger No 663406755: Global MASTER-Net observations report
  80. GRB 220107A: AbAO and Terskol optical observations
  81. GRB 211227A: Deep early CAHA 2.2m/CAFOS observation
  82. Fermi GRB 211229A: Global MASTER-Net observations report
  83. Konus-Wind detection of the intermediate flare from SGR 1935+2154
  84. GRB 211227A: Liverpool Telescope upper limits
  85. GRB 211227A: LCO Optical Observations
  86. GRB 211227A: MAXI/GSC detection
  87. GRB 211225A: MITSuME Akeno optical upper limits
  88. Swift GRB 211225B: Global MASTER-Net observations report
  89. Fermi GRB 211225C: Global MASTER-Net observations report
  90. GRB 211225A/MAXI J0827-071: MAXI/GSC detection
  91. GRB 211218A: MITSuME Akeno optical upper limits
  92. GRB 211218A, MAXI J0909-041: MAXI/GSC detection
  93. MAXI GRB211218.04: Global MASTER-Net observations report
  94. GRB 211212A: Fermi GBM Final Real-time Localization
  95. Fermi GRB 211211B: Global MASTER-Net observations report
  96. Fermi trigger No 660736561: Global MASTER-Net observations report
  97. Fermi GRB 211204A: Global MASTER-Net observations report
  98. Fermi GRB 211130A: Global MASTER-Net observations report
  99. GRB 211129A: Swift/UVOT Upper Limits
  100. IceCube-Cascade 211128A: Upper limits from a search for additional neutrino events in IceCube

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