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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"

33648 results found.

  1. GRB 220827A: Fermi GBM Final Real-time Localization
  2. GRB 220826A: Swift-BAT refined analysis
  3. GRB 220826A: Fermi GBM observation
  4. GRB 220826A: Swift-XRT refined Analysis
  5. GRB 220825A: Fermi GBM observation
  6. GRB 220826A: Lesedi optical afterglow detection
  7. GRB 220826A: Swift/UVOT Detection
  8. GRB 220826A: iTelescope optical afterglow observations
  9. Swift GRB 220826A: Global MASTER-Net observations report
  10. GRB 220826A: Enhanced Swift-XRT position
  11. GRB 220826A: Swift detection of a burst with an optical counterpart
  12. GRB 220825A: Swift/BAT-GUANO detection
  13. GRB 220825A: Fermi GBM Final Localization
  14. GRB 220823A: Fermi GBM detection
  15. GRB 220823A: Swift/BAT-GUANO detection of a short burst
  16. GRB 220821A: Fermi GBM Final Real-time Localization
  17. Konus-Wind detection of GRB 220813A
  18. GRB 220813A: VLT optical observations and possible host galaxy
  19. GRB 220813A: Swift/UVOT Detection
  20. GRB 220810A: Further Swift-XRT observations
  21. GRB 220813A: Swift-XRT refined Analysis
  22. Swift GRB 220813A: Global MASTER-Net observations report
  23. GRB 220813A: Enhanced Swift-XRT position
  24. GRB 220813A: Swift detection of a burst with an optical counterpart
  25. GRB 220810A: Swift-XRT observations
  26. GRB 220719A: Detection by VZLUSAT-2
  27. GRB 220810A: Swift ToO observations
  28. GRB 220810A: MeerLICHT detection of two afterglow candidates
  29. Fermi GBM trigger 681998863/220812505 is not a GRB
  30. Fermi GBM trigger 681890304/220811249 is not a GRB
  31. Fermi GRB 220810A: Global MASTER-Net observations report
  32. GRB 220810A: Fermi GBM Final Real-time Localization
  33. GRB 220627A: MeerKAT radio observations
  34. GRB 220806A: Swift-BAT refined analysis
  35. Fermi GBM trigger 681719116/220809267 is not a GRB
  36. Fermi GBM trigger 681633544/220808277 is not a GRB
  37. Fermi GBM trigger 681547990 / 220807287 is not a GRB
  38. GRB 220806A: Swift detection of a burst
  39. GRB 220804A: Fermi GBM Final Localization
  40. GRB 220803A: AstroSat CZTI detection
  41. Konus-Wind detection of GRB 220730A (short)
  42. GRB 220730A: Swift-BAT refined analysis
  43. GRB 220730A: Fermi GBM detection
  44. GRB 220730A: Swift-XRT afterglow detection
  45. GRB 220730A: Swift/UVOT Upper Limits
  46. GRB 220730A: Swift-XRT observations
  47. GRB 220729A: AstroSat CZTI detection
  48. Swift GRB 220730A: Global MASTER-Net observations report
  49. GRB 220730A: Swift detection of a short hard burst
  50. Fermi GRB 220728A: Global MASTER-Net observations report
  51. GRB 220728A: Fermi GBM Final Real-time Localization
  52. GRB 220726A: Fermi GBM Final Real-time Localization
  53. Fermi GRB 220724A: Global MASTER-Net observations report
  54. GRB 220724A: Fermi GBM Final Real-time Localization
  55. GRB 220715B: VIRT Optical Upper Limit
  56. Fermi GRB 220721A: Global MASTER-Net observations report
  57. GRB 220721A: Fermi GBM Final Real-time Localization
  58. Retraction: Fermi GBM trigger 679932336.585264/220719587 is not a GRB
  59. GRB 220715A: CALET Gamma-Ray Burst Monitor detection
  60. GRB 220711B: CALET Gamma-Ray Burst Monitor detection
  61. GRB 220719A: Fermi GBM Final Real-time Localization
  62. GRB 220715B: Swift-BAT refined analysis
  63. GRB220714B: UVOT detections
  64. GRB 220715B: Fermi GBM detection
  65. GRB 220715B: Swift-XRT refined Analysis
  66. GRB 220715B: Swift/UVOT Upper Limits
  67. GRB 220715B: Enhanced Swift-XRT position
  68. GRB 220715B: BOOTES-network optical upper limits
  69. Swift GRB 220715B: Global MASTER-Net observations report
  70. GRB 220715B: Prompt enhanced Swift-XRT position
  71. GRB 220715B: Swift detection of a burst
  72. GRB 220715B: Fermi GBM Final Real-time Localization
  73. GRB 220714B: Swift-BAT refined analysis
  74. GRB 220714B: Fermi GBM observation
  75. GRB 220715A: AGILE/MCAL detection
  76. GRB 220714B: LCO Optical Observations
  77. GRB 220715A: Fermi GBM Final Real-time Localization
  78. GRB 220714B: Swift-XRT refined Analysis
  79. Swift/BAT Trigger 1116172 (=GRB 220714A) is not a real astrophysical event
  80. GRB 220714B: UVOT afterglow discovery
  81. GRB 220714B: Enhanced Swift-XRT position
  82. GRB 220713A: Fermi GBM Final Localization
  83. GRB 220714B: Swift detection of a burst
  84. GRB 220714B: Fermi GBM Final Real-time Localization
  85. GRB 220714A: Possible Swift detection of a burst
  86. GRB 220710A: Swift/UVOT Upper Limits
  87. GRB 220711C: Fermi GBM Observation
  88. Retraction of GRB 220711B: 10.4 m GTC(+EMIR) observations (GCN 32387)
  89. GRB 220711B: 10.4 m GTC(+EMIR) observations
  90. GRB 220711B: 10.4 m GTC(+EMIR) observations
  91. GRB 220710A: Swift-XRT afterglow detection
  92. GRB 220711C: Swift/BAT-GUANO detection outside the coded FOV
  93. GRB 220711B, GROND observations
  94. Konus-Wind detection of GRB 220711C
  95. GRB 220711B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  96. GRB 220711B: GIT optical upper limits
  97. Fermi GRB 220711B: Global MASTER-Net observations report
  98. GRB 220712B: NOT optical afterglow confirmation
  99. GRB 220710A: Swift ToO observations
  100. GRB 220710A: Swift/BAT-GUANO arcminute localization

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