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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 170813A: Swift detection of a burst
  2. LIGO/Virgo G296853: Liverpool Telescope classification of MASTER OT J013646.48-140323.5
  3. GRB 170728B: 15 GHz upper limits from AMI
  4. GRB 170728A: 15 GHz upper limits from AMI
  5. GRB 170714A: 15 GHz upper limits from AMI
  6. GRB 170711A: 15 GHz upper limits from AMI
  7. GRB 170710C: 15 GHz upper limits from AMI
  8. GRB 170710B: 15 GHz upper limits from AMI
  9. GRB 170626A: 15 GHz upper limits from AMI
  10. LIGO/Virgo G296853: BOOTES-1 and GTC optical observations
  11. GRB 170810A: Swift-BAT refined analysis
  12. LIGO/Virgo G296853: Insight-HXMT observations
  13. LIGO/Virgo G296853 : MAXI/GSC observations
  14. GRB 170810A: Swift-XRT refined Analysis
  15. GRB 170810A: Swift/UVOT Detection
  16. GRB 170810A: Fermi GBM observation
  17. GRB 170810A: Fermi-LAT detection
  18. GRB 170810A: Enhanced Swift-XRT position
  19. GRB 170810A: Swift detection of a burst with a bright optical counterpart
  20. GRB 170810A: MASTER-NET very bright OT detection
  21. LIGO/Virgo G296853: HAWC follow-up
  22. Konus-Wind observation of GRB 170808B
  23. LIGO/Virgo G296853: Super-AGILE observations
  24. LIGO/Virgo G296853: MASTER SN detection near center error-area
  25. GRB 170805B: Insight-HXMT observation
  26. GRB 170803B: Insight-HXMT detection
  27. Konus-Wind observation of GRB 170805B
  28. GMRT upper limit on the radio afterglow of GRB 170728B
  29. LIGO/Virgo G296853: no INTEGRAL data at the time of the event
  30. LIGO/Virgo G296853: Fermi-LAT search for high-energy gamma-ray counterpart
  31. LIGO/Virgo G296853: Fermi GBM Observations
  32. LIGO/Virgo G296853: AGILE GRID observations
  33. LIGO/Virgo G296853: Swift/BAT data search
  34. LIGO/Virgo G296853: MASTER follow up observations
  35. LIGO/Virgo G296853: AGILE MCAL observations
  36. LIGO/Virgo G296853 ANTARES search
  37. LIGO/Virgo G296853: IceCube neutrino observations
  38. LIGO/Virgo G296853: Identification of a GW Binary Merger Candidate
  39. GRB 170808B: Fermi LAT Detection
  40. GRB 170808B: Fermi GBM observation
  41. IPN Triangulation of GRB 170805B (short/hard)
  42. IPN Triangulation of GRB 170805A (short)
  43. GRB 170801A: Insight-HXMT detection
  44. Konus-Wind observation of GRB 170724A
  45. GRB 170714A: ATCA detection of the radio counterpart
  46. GRB 170807A: Swift-BAT refined analysis
  47. GRB 170808A: MAXI/GSC detection
  48. GRB 170805A: Insight-HXMT detection
  49. GRB 170807A: Swift detection of a burst
  50. GRB 170728B: TShAO, SAO RAS and AbAO optical observations
  51. GRB 170803A: Swift/BAT spectral lag results
  52. GRB 170804A: LCO Observations
  53. GRB 170804A: Swift-BAT refined analysis
  54. GRB 170804A: Swift/UVOT Detection
  55. GRB 170804A: Swift-XRT refined Analysis
  56. GRB 170804A: Enhanced Swift-XRT position
  57. GRB 170803A: Swift-BAT refined analysis
  58. GRB 170803A: Swift/UVOT Detection
  59. GRB 170804A: Swift detection of a burst with optical counterpart
  60. Swift Trigger 766161 is not a GRB
  61. GRB 170803A: Swift-XRT refined Analysis
  62. GRB 170803A: Enhanced Swift-XRT position
  63. GRB 170803A: Fermi GBM observation
  64. GRB 170803A: Swift detection of a burst with an optical counterpart
  65. GRB 170802A: Fermi GBM detection
  66. Swift Trigger 765783 is not an astrophysical event.
  67. GRB 160814A: Lomonosov BDRG gamma ray discovery
  68. GRB 170728B: time correction to MASTER GCN Circular 21391
  69. Swift J181723.1-164300: Swift detection of another pulse of the new Galactic source
  70. GRB 170728B: Swift/UVOT Further Analysis
  71. Konus-Wind observation of GRB 170728B
  72. GRB 170726A: AstroSat CZTI detection
  73. GRB 170714A: Chandra observations
  74. GRB 170728B: VLA radio afterglow detection
  75. GRB 170728B: Optical observations at Crni Vrh
  76. GRB 170728B: BOOTES-2/TELMA optical detection during the extended gamma-ray phase
  77. GRB170730A detecetd by INTEGRAL. Refined analysis
  78. GRB 170728B: MASTER-IAC first minute short GRB early OT detection
  79. IBAS weak Alert nr.7881: possible GRB 170730A
  80. GRB 170728B: COATLI Observations And Confirmation of Fading
  81. GRB 170728B: Swift/UVOT Upper Limits
  82. GRB 170728B iTelescope observation
  83. GRB 170728A: Swift/UVOT Detection
  84. Swift J181723.1-164300: Swift-BAT refined analysis
  85. GRB 170728B, Swift-BAT refined analysis
  86. GRB 170728B: Fermi GBM detection
  87. GRB 170728A: LCO observations
  88. GRB 170728B: I-band detection from 1.5m OSN
  89. GRB 170728B: Fermi-LAT detection
  90. GRB170714A: XMM observation of the afterglow
  91. GRB 170728A: Swift-XRT refined Analysis
  92. GRB 170728B: Enhanced Swift-XRT position
  93. GRB 170728B: Swift-XRT refined Analysis
  94. GRB 170728B: LT afterglow confirmation
  95. GRB 170728B: NOT optical afterglow confirmation
  96. GRB 170728B: position of the TNG optical counterpart
  97. GRB 170728B: TNG optical afterglow candidate
  98. GRB 170728B: Swift detection of a short burst
  99. GRB 170728A: Swift-BAT refined analysis
  100. Swift triggers on a new galactic source: Swift J181723.1-164300

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