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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"

21577 results found.

  1. Konus-Wind detection of GRB 220921A
  2. IceCube-220907A: Classification of AT2022oyn as a Type Ia supernova
  3. GRB 220921A: MeerLICHT afterglow observations
  4. GRB 220921A: Swift-XRT Observations
  5. GRB 220921A: MASTER OT inside Fermi-LAT error-box
  6. LAT GRB220921.46: Global MASTER-Net observations report
  7. GRB 220921A: Tiled Swift observations
  8. Fermi trigger No 685452089: Global MASTER-Net observations report
  9. Fermi-LAT gamma-ray observations of IceCube-220918A and detection of a new gamma-ray source, Fermi J0502.5+0037
  10. IceCube Alert 220918.53: Global MASTER-Net observations report
  11. Fermi trigger No 684894705: Global MASTER-Net observations report
  12. Fermi trigger No 684927323: Global MASTER-Net observations report
  13. Fermi trigger No 684911625: Global MASTER-Net observations report
  14. Konus-Wind detection of GRB 220910A
  15. Fermi trigger No 684716840: Global MASTER-Net observations report
  16. Fermi GRB 220912A: Global MASTER-Net observations report
  17. GRB 220831A: DECam optical counterpart follow-up
  18. GRB 220909A: Swift-XRT observations
  19. GRB 220909A: Swift ToO observations
  20. GRB 220909A: Swift/BAT-GUANO candidate arcminute localization
  21. GRB 220831A: Gemini-South Infrared Observations
  22. IceCube-220907A: One Candidate Counterpart from the Zwicky Transient Facility
  23. GRB 220831A: Gemini-South/GMOS detection of potential optical counterpart
  24. GRB 220907A: Swift/UVOT Upper Limits
  25. GRB 220831A: ATCA 5/9 GHz radio observations
  26. Fermi-LAT Gamma-ray Observations of IceCube-220907A
  27. Swift GRB220907.59: Global MASTER-Net observations report
  28. IceCube Alert 220907.28: Global MASTER-Net observations report
  29. GRB 220831A: Swift-UVOT Upper Limits
  30. Fermi GRB 220905A: Global MASTER-Net observations report
  31. GRB 220831A: DECam detection of a possible optical counterpart
  32. Fermi GRB 220902A: Global MASTER-Net observations report
  33. GRB 220831A, VLT/HAWK-I near-infrared observations
  34. GRB 220831A: Swift-XRT observations
  35. GRB 220831A: Swift ToO observations
  36. Fermi trigger No 683654200: Global MASTER-Net observations report
  37. GRB 220831A: Swift/BAT-GUANO localization of a short burst
  38. Fermi trigger No 683646997: Global MASTER-Net observations report
  39. Fermi trigger No 683537972: Global MASTER-Net observations report
  40. Fermi trigger No 683476673: Global MASTER-Net observations report
  41. IceCube-220822A: Classification of AT2022saw as a Type Ia supernova
  42. Fermi trigger No 683202084: Global MASTER-Net observations report
  43. Fermi trigger No 683183601: Global MASTER-Net observations report
  44. Fermi trigger No 683152759: Global MASTER-Net observations report
  45. GRB 220826A: Swift/UVOT Detection
  46. GRB 220826A: iTelescope optical afterglow observations
  47. Swift GRB 220826A: Global MASTER-Net observations report
  48. GRB 220825A: Swift/BAT-GUANO detection
  49. IceCube-220822A: One Candidate Counterpart from the Zwicky Transient Facility
  50. Fermi-LAT gamma-ray observations of IceCube-220822A and detection of a new gamma-ray source, Fermi J1810.1+2154
  51. Fermi trigger No 682918137: Global MASTER-Net observations report
  52. GRB 220823A: Swift/BAT-GUANO detection of a short burst
  53. IceCube Alert 220822.85: Global MASTER-Net observations report
  54. GRB 220813A: VLT optical observations and possible host galaxy
  55. GRB 220813A: Swift/UVOT Detection
  56. GRB 220810A: Further Swift-XRT observations
  57. Swift GRB 220813A: Global MASTER-Net observations report
  58. GRB 220810A: Swift-XRT observations
  59. Fermi trigger No 681998863: Global MASTER-Net observations report
  60. GRB 220810A: Swift ToO observations
  61. GRB 220810A: MeerLICHT detection of two afterglow candidates
  62. Fermi trigger No 681890304: Global MASTER-Net observations report
  63. Fermi GRB 220810A: Global MASTER-Net observations report
  64. GRB 220627A: MeerKAT radio observations
  65. Fermi trigger No 681719116: Global MASTER-Net observations report
  66. Fermi trigger No 681633544: Global MASTER-Net observations report
  67. IceCube Alert 220808.33: Global MASTER-Net observations report
  68. Swift GRB220806.76: Global MASTER-Net observations report
  69. Fermi trigger No 681271717: Global MASTER-Net observations report
  70. Fermi trigger No 681212354: Global MASTER-Net observations report
  71. GRB 220730A: Swift-XRT afterglow detection
  72. GRB 220730A: Swift/UVOT Upper Limits
  73. GRB 220730A: Swift-XRT observations
  74. Swift GRB 220730A: Global MASTER-Net observations report
  75. Fermi trigger No 680782656: Global MASTER-Net observations report
  76. Fermi GRB 220728A: Global MASTER-Net observations report
  77. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220728A
  78. Fermi trigger No 680421061: Global MASTER-Net observations report
  79. Fermi GRB 220724A: Global MASTER-Net observations report
  80. Fermi GRB 220721A: Global MASTER-Net observations report
  81. GRB220714B: UVOT detections
  82. GRB 220715B: Swift/UVOT Upper Limits
  83. Swift GRB 220715B: Global MASTER-Net observations report
  84. GRB 220714B: LCO Optical Observations
  85. GRB 220710A: Swift/UVOT Upper Limits
  86. Retraction of GRB 220711B: 10.4 m GTC(+EMIR) observations (GCN 32387)
  87. GRB 220711B: 10.4 m GTC(+EMIR) observations
  88. GRB 220711B: 10.4 m GTC(+EMIR) observations
  89. GRB 220710A: Swift-XRT afterglow detection
  90. GRB 220711C: Swift/BAT-GUANO detection outside the coded FOV
  91. GRB 220711B, GROND observations
  92. GRB 220711B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  93. GRB 220711B: GIT optical upper limits
  94. Fermi trigger No 679248723: Global MASTER-Net observations report
  95. Fermi GRB 220711B: Global MASTER-Net observations report
  96. GRB 220712B: NOT optical afterglow confirmation
  97. GRB 220710A: Swift ToO observations
  98. GRB 220710A: Swift/BAT-GUANO arcminute localization
  99. GRB 220711B: Swift/UVOT Upper Limits
  100. GRB 220711B: NOT optical observations

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