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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"

30480 results found.

  1. GRB 220921A: Tiled Swift observations
  2. Fermi-LAT gamma-ray observations of IceCube-220918A and detection of a new gamma-ray source, Fermi J0502.5+0037
  3. IceCube-220918A: Upper limits from a search for additional neutrino events in IceCube
  4. IceCube-220907A: No significant detection in HAWC
  5. GRB 220909A: Fermi GBM observation
  6. Konus-Wind detection of GRB 220910A
  7. Fermi GRB 220912A: Global MASTER-Net observations report
  8. GRB 220910A: Fermi GBM observation
  9. IPN triangulation of GRB 220910A (bright/long)
  10. GRB 220912A: AstroSat CZTI detection
  11. GRB 220831A: DECam optical counterpart follow-up
  12. GRB 220909A: Swift-XRT observations
  13. IPN triangulation of GRB 220905A
  14. GRB 220909A: Swift ToO observations
  15. GRB 220909A: Swift/BAT-GUANO candidate arcminute localization
  16. GRB 220831A: Gemini-South Infrared Observations
  17. GRB 220910A: AstroSat CZTI detection
  18. GRB 220907A: Swift-BAT refined analysis
  19. IceCube-220907A: One Candidate Counterpart from the Zwicky Transient Facility
  20. GRB 220831A: Gemini-South/GMOS detection of potential optical counterpart
  21. IPN triangulation of GRB 220903A (long)
  22. GRB 220907A: Fermi GBM observation
  23. GRB 220907A: Nanshan/NEXT optical upper limits
  24. GRB 220907A: Swift/UVOT Upper Limits
  25. GRB 220907A: Swift-XRT refined Analysis
  26. GRB 220831A: ATCA 5/9 GHz radio observations
  27. Fermi-LAT Gamma-ray Observations of IceCube-220907A
  28. GRB 220907A: Swift-XRT position
  29. GRB 220907A: Swift detection of a burst
  30. GRB 220831A: Swift-UVOT Upper Limits
  31. Fermi GRB 220905A: Global MASTER-Net observations report
  32. Introducing Self-Service Configuration of GCN Notices over Email for Transient Alerts
  33. GRB 220831A: DECam detection of a possible optical counterpart
  34. Fermi GRB 220902A: Global MASTER-Net observations report
  35. GRB 220831A, VLT/HAWK-I near-infrared observations
  36. GRB 220831A: Fermi GBM observation
  37. GRB 220831A: Swift-XRT observations
  38. GRB 220831A: Swift ToO observations
  39. GRB 220831A: Swift/BAT-GUANO localization of a short burst
  40. IceCube-220822A: No significant detection in HAWC
  41. Konus-Wind detection of GRB 220826A
  42. IceCube-220822A: Classification of AT2022saw as a Type Ia supernova
  43. GRB 220826A: Swift-BAT refined analysis
  44. GRB 220826A: Fermi GBM observation
  45. GRB 220826A: Swift-XRT refined Analysis
  46. GRB 220825A: Fermi GBM observation
  47. GRB 220826A: Lesedi optical afterglow detection
  48. GRB 220826A: Swift/UVOT Detection
  49. GRB 220826A: iTelescope optical afterglow observations
  50. Swift GRB 220826A: Global MASTER-Net observations report
  51. IceCube-220822A: One Candidate Counterpart from the Zwicky Transient Facility
  52. GRB 220823A: Fermi GBM detection
  53. Fermi-LAT gamma-ray observations of IceCube-220822A and detection of a new gamma-ray source, Fermi J1810.1+2154
  54. Konus-Wind detection of GRB 220813A
  55. GRB 220813A: VLT optical observations and possible host galaxy
  56. GRB 220813A: Swift/UVOT Detection
  57. GRB 220810A: Further Swift-XRT observations
  58. GRB 220813A: Swift-XRT refined Analysis
  59. Swift GRB 220813A: Global MASTER-Net observations report
  60. GRB 220810A: Swift-XRT observations
  61. GRB 220810A: Swift ToO observations
  62. GRB 220810A: MeerLICHT detection of two afterglow candidates
  63. Fermi GRB 220810A: Global MASTER-Net observations report
  64. GRB 220627A: MeerKAT radio observations
  65. GRB 220806A: Swift-BAT refined analysis
  66. Konus-Wind detection of GRB 220730A (short)
  67. GRB 220730A: Swift-BAT refined analysis
  68. GRB 220730A: Fermi GBM detection
  69. GRB 220730A: Swift-XRT afterglow detection
  70. GRB 220730A: Swift/UVOT Upper Limits
  71. GRB 220730A: Swift-XRT observations
  72. Swift GRB 220730A: Global MASTER-Net observations report
  73. Fermi GRB 220728A: Global MASTER-Net observations report
  74. Fermi GRB 220724A: Global MASTER-Net observations report
  75. GRB 220715B: VIRT Optical Upper Limit
  76. Fermi GRB 220721A: Global MASTER-Net observations report
  77. Introducing new GCN Kafka broker and web site for transient alerts, https://gcn.nasa.gov
  78. Retraction: Fermi GBM trigger 679932336.585264/220719587 is not a GRB
  79. GRB 220715A: CALET Gamma-Ray Burst Monitor detection
  80. GRB 220711B: CALET Gamma-Ray Burst Monitor detection
  81. GRB 220715B: Swift-BAT refined analysis
  82. GRB220714B: UVOT detections
  83. GRB 220715B: Fermi GBM detection
  84. GRB 220715B: Swift-XRT refined Analysis
  85. GRB 220715B: Swift/UVOT Upper Limits
  86. Swift GRB 220715B: Global MASTER-Net observations report
  87. GRB 220714B: Swift-BAT refined analysis
  88. GRB 220714B: Fermi GBM observation
  89. GRB 220715A: AGILE/MCAL detection
  90. GRB 220714B: LCO Optical Observations
  91. GRB 220714B: Swift-XRT refined Analysis
  92. Swift/BAT Trigger 1116172 (=GRB 220714A) is not a real astrophysical event
  93. GRB 220714B: UVOT afterglow discovery
  94. GRB 220710A: Swift/UVOT Upper Limits
  95. GRB 220711C: Fermi GBM Observation
  96. Retraction of GRB 220711B: 10.4 m GTC(+EMIR) observations (GCN 32387)
  97. GRB 220711C: Swift/BAT-GUANO detection outside the coded FOV
  98. GRB 220711B, GROND observations
  99. Konus-Wind detection of GRB 220711C
  100. GRB 220711B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)

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