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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"

35259 results found.

  1. GRB 170921B: Fermi GBM detection
  2. GRB 170921A: Swift detection of a burst
  3. Fermi-GBM GRB misclassifications
  4. GRB 170912C: Insight-HXMT detection
  5. Fermi GBM trigger 527149931/170915272 is not a GRB
  6. GRB 170906A CALET Gamma-Ray Burst Monitor detection
  7. GRB 170912B: Swift/UVOT Upper Limits
  8. Fermi GBM trigger 526978609/170913289 is not a GRB
  9. GRB 170912B: Swift-BAT refined analysis
  10. GRB 170912A: Swift-BAT refined analysis
  11. GRB 170912A: Swift-XRT refined Analysis
  12. GRB 170912A: Swift/UVOT Upper-Limits
  13. GRB 170912B: Swift-XRT refined Analysis
  14. GRB 170912B: Fermi GBM observations
  15. LIGO/Virgo G298936: Konus-Wind observations
  16. LIGO/Virgo G299232: Konus-Wind observations
  17. GRB 170911A: Fermi GBM observation
  18. GRB 170912B: Enhanced Swift-XRT position
  19. GRB 170912B: Swift detection of a burst
  20. GRB 170912A: Enhanced Swift-XRT position
  21. GRB 170912A: Prompt enhanced Swift-XRT position
  22. GRB 170912A: Swift detection of a burst
  23. Konus-Wind observation of GRB 170906A
  24. GRB 170911A: MAXI/GSC detection
  25. Konus-Wind observation of GRB 170906C
  26. GRB 170906A: AstroSat CZTI(Veto) detection
  27. GRB 170830B CALET Gamma-Ray Burst Monitor detection
  28. IBAS Alert nr. 7913 is not a real GRB
  29. Fermi-GBM GRB mis-classifications during current Solar activity
  30. Konus-Wind observation of GRB 170904A
  31. GRB 170906A: Swift/UVOT Detection
  32. GRB 170906B: Swift/UVOT Upper Limits
  33. GRB 170906B: Swift-XRT refined Analysis
  34. GRB 170906C: optical observations
  35. GRB 170906B: Swift-BAT refined analysis
  36. GRB 170906B: Fermi GBM detection
  37. GRB 170906A: Fermi GBM detection
  38. GRB 170906A: Swift-BAT refined analysis
  39. GRB 170906C: COATLI Observations
  40. GRB 170906A: Swift-XRT refined Analysis
  41. GRB 170906C: Swift/UVOT Upper Limits
  42. GRB 170906C: Swift-XRT refined Analysis
  43. GRB 170906C: Swift-BAT refined analysis
  44. GRB 170906C: Enhanced Swift-XRT position
  45. GRB 170906A: MASTER-OAFA (Argentina) early automatic OT detection
  46. GRB 170829A: Insight-HXMT detection
  47. GRB 170906C: Swift-XRT observations
  48. GRB 170906A: Fermi-LAT detection
  49. GRB 170906C: Swift detection of a burst
  50. GRB 170906A: REM optical/NIR observations
  51. GRB 170906A: Enhanced Swift-XRT position
  52. GRB 170906B: Enhanced Swift-XRT position
  53. GRB 170906B: Swift detection of a burst
  54. GRB 170906A: Swift detection of a burst with an optical afterglow
  55. IPN Triangulation of GRB 170904A (long/very bright)
  56. GRB 170901B: Insight-HXMT detection
  57. GRB 170904A: Insight-HXMT detection
  58. GRB 170903A: Fermi GBM observation
  59. GRB 170827A: LCO Observations
  60. GRB 170903A: Swift/UVOT Upper Limits
  61. GRB 170903A: UAFO /ISON optical upper limit
  62. GRB 170903A: MITSuME Okayama upper limits
  63. GRB 170903A: Swift-XRT refined Analysis
  64. GRB 170903A: Host galaxy redshift from OSIRIS/GTC
  65. GRB 170903A: Enhanced Swift-XRT position
  66. GRB 170903A: Swift-BAT refined analysis
  67. GRB 170903A: Nanshan optical upper limit
  68. GRB 170903A: Swift-XRT observations
  69. GRB 170903A: Swift detection of a burst
  70. Swift Trigger 770431 (GRB 170902A) is a not a GRB
  71. GRB 170902A: Enhanced Swift-XRT position
  72. GRB 170902A: Swift detection of a burst or possible Galactic transient
  73. LIGO/Virgo G298048
  74. GRB 170831A: Fermi GBM detection
  75. GRB 170830A: Fermi GBM observation
  76. Konus-Wind observation of GRB 170827B
  77. Konus-Wind observation of GRB 170826A
  78. GRB 170830A: Astrosat CZTI detection
  79. Konus-Wind observation of GRB 170826B
  80. LIGO/Virgo G298048: Discovery of X-ray emission from SSS17a in NGC4993
  81. GRB 170830A: iTelescope optical observations
  82. GRB 170830A: MAXI/GSC detection
  83. LIGO/Virgo G299232 : RATIR Optical and NIR Observations of Swift UVOT source
  84. IPN Triangulation of GRB 170826B
  85. LIGO/Virgo G298048: ALMA observations
  86. LIGO/Virgo G298048: Konus-Wind observations
  87. GRB170827A: Further GROND follow-up observations
  88. GRB 170826B: Insight-HXMT detection
  89. IPN Triangulation of GRB 170827B (short)
  90. IPN Triangulation of GRB 170826A (short)
  91. LIGO/Virgo G298936: HAWC follow-up
  92. GRB 170827A: Swift-XRT refined Analysis
  93. GROND observations of GRB170827A
  94. GRB 170827A: ePESSTO NTT afterglow candidate
  95. GRB 170823A: TAROT Calern observatory optical observations
  96. GRB 170827A, Swift-BAT refined analysis
  97. GRB 170827A: Swift/UVOT Upper Limits
  98. GRB 170827A: REM optical/NIR observations
  99. GRB 170827A: Swift detection of a burst
  100. GRB 170826B: Fermi GBM detection

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