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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"
  1. GRB 160525B: Enhanced Swift-XRT position
  2. Konus-Wind observation of GRB 160521B
  3. GRB 160525A: Swift-BAT refined analysis
  4. GRB 160525B: Prompt enhanced Swift-XRT position
  5. GRB 160525B: Swift detection of a burst
  6. GRB 160525A: Swift detection of a probable burst
  7. Correction - Fermi/GBM trigger 160523919 is a GRB
  8. GRB 160521B: Theoretical estimate of the redshift and urgent need for further x-ray observations
  9. The nature of the Fermi/GBM trigger 160523919 is unknown.
  10. GRB 160425A: SMARTS late-time observations
  11. GRB 160327A: 15 GHz upper limits from AMI
  12. GRB 160321A: 15 GHz upper limits from AMI
  13. GRB 160314A: 15 GHz upper limits from AMI
  14. GRB 160313A: 15 GHz upper limits from AMI
  15. GRB 160521B: Swift/UVOT Upper Limits
  16. GRB 160521B: Swift-XRT observations
  17. Another Swift detection of SGR 1935+2154 (trigger #687124)
  18. Swift detection of SGR 1935+2154
  19. GRB 160521B: Swift ToO observations
  20. GRB 160521B: Fermi-LAT detection
  21. GRB 160521B: Fermi GBM detection
  22. GRB 160521A: a long GRB detected by INTEGRAL
  23. GRB 160519A: Swift-BAT refined analysis
  24. Swift-BAT trigger 686845 was due to noise near a known source
  25. GRB 160519A: Fermi GBM detection
  26. Konus-Wind observation of a bright burst from SGR 1935+2154
  27. FERMI GBM bursts from the magnetar SGR 1935+2154
  28. GRB 160519A: Swift detection of a burst
  29. SGR 1935+2154: AbAO optical upper limit
  30. Fermi GBM triggers of SGR 1935+2154
  31. Trigger 686761: Swift detection of a bright burst from SGR 1935+2154
  32. Fermi GBM trigger 485205628 /160517806 is not a GRB
  33. Fermi GBM trigger 485124591/160516868 is not a GRB
  34. Trigger 686443: Swift detection of SGR 1935+2154
  35. Fermi GBM trigger 484906918/160514349 is not a GRB
  36. GRB 160509A: Further VLA Observations
  37. FACT follow-up of the IceCube event 160427A
  38. Interplanetary Network Search for IceCube 160427A
  39. GRB 160509A MASTER-NET observations
  40. GRB 160509A: CALET Gamma-Ray Burst Monitor detection
  41. GRB 160509A: non-observation of VHE emission with HAWC
  42. GRB 160508A: CALET Gamma-Ray Burst Monitor detection
  43. GRB 160509A: TLS Tautenburg Afterglow Detection
  44. GRB 160509A: Further Swift/UVOT Observations
  45. GRB 160509A Gemini North redshift
  46. Fermi GBM trigger 484574960/160510506 is not a GRB
  47. Konus-Wind observation of GRB 160509A
  48. GRB 160509A: DCT Imaging / Afterglow Confirmation
  49. GRB 160509A: MAXI/GSC refined analysis
  50. GRB 160509A: VLA Detection
  51. GRB 160509A: Fermi-LAT refined analysis
  52. GRB 160509A: Swift/UVOT Upper Limit
  53. GRB 160509A: Fermi GBM Detection
  54. GRB 160509A Gemini North candidate afterglow
  55. GRB 160509A: optical observations
  56. GRB 160509A: Swift-XRT afterglow detection
  57. GRB 160509A: Preliminary XRT positon
  58. GRB 160509A: Tiled Swift observations
  59. Correction to GCN 19404; GRB 160509A: MAXI/GSC detection
  60. GRB 160227A: MAXI/GSC detection
  61. GRB 160509A: Fermi-LAT prompt detection of a very bright burst
  62. GRB 160506A: TAROT La Silla observatory optical observations
  63. LIGO/Virgo G211117: Astrosat CZTI upper limits
  64. GRB 160506A: IRSF upper limits
  65. GRB 160506A: Swift-XRT refined Analysis
  66. GRB 160506A: Swift/UVOT Upper Limits
  67. GRB 160506A: Swift-BAT refined analysis
  68. GRB 160506A: GROND upper limits
  69. GRB 160506A: Enhanced Swift-XRT position
  70. GRB 160506A: Swift detection of a burst
  71. GRB 160504A: Swift-BAT refined analysis
  72. IceCube-160427A: iPTF Observations
  73. GRB 160504A: RATIR Optical and NIR Observations
  74. GRB 160504A: Swift/UVOT Upper Limits
  75. GRB160504A: Gemini NIR Observations
  76. GRB 160504A: Bassano Bresciano Observatory upper limits
  77. GRB 160504A: Swift-XRT refined Analysis
  78. GRB 160504A: Enhanced Swift-XRT position
  79. GRB 160504A: NOT upper limits
  80. GRB 160417A, the review of the sky area in plate archive
  81. GRB 160504A: TAROT Calern observatory optical observations
  82. GRB 160504A: Swift detection of a burst
  83. ICECUBE-160427A : Pan-STARRS imaging and optical transients in the field
  84. GRB 160503A: Fermi GBM observation
  85. GRB 160503A: Fermi-LAT detection
  86. GRB 160501A: SMARTS optical/IR observations
  87. VERITAS rapid follow-up observations of IceCube event 160427A
  88. GRB 160501A: Swift-BAT refined analysis
  89. GRB 160501A: GROND Upper limits
  90. GRB 160501A: MITSuME Okayama upper limits
  91. GRB 160501A: UKIRT near-IR upper limits
  92. GRB 160501A: Swift/UVOT Upper Limits
  93. GRB 160501A: Swift-XRT refined Analysis
  94. GRB 160501A: RATIR Optical and NIR Observations
  95. GRB 160501A: Enhanced Swift-XRT position
  96. GRB 160501A: TAROT Calern observatory optical observations
  97. GRB 160501A MASTER-NET early observations
  98. GRB 160501A: NOT optical and NIR observations
  99. GRB 160501A: Swift detection of a burst
  100. IceCube-160427A: Fermi GBM Observations

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