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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"

28054 results found.

  1. GRB 190204A: Swift-XRT refined Analysis
  2. Swift Trigger 887541: MASTER inspect
  3. GRB 190204A: MAXI/GSC detection
  4. GRB 190202A: R and I band observation from HCT
  5. GRB 190204A: Swift detection of a burst with a possible optical counterpart
  6. GRB 190203A: MASTER OT detection
  7. Swift Trigger 887541: Swift detection of Swift J1728.9-3613
  8. GRB 190203A: Enhanced Swift-XRT position
  9. GRB 190203A: SAO RAS optical observations, afterglow fading
  10. GRB 190203A: Koshka Zeiss-1000 optical upper limit
  11. GRB 190203A: Swift detection of a burst with an optical counterpart
  12. GRB 190202A: SAO RAS optical observations
  13. GRB 190202A: TSHAO optical observations
  14. GRB 190202A: Swift-XRT refined Analysis
  15. GRB 190202A: LCO-CTIO optical observations
  16. GRB 190202A: Fermi GBM observation
  17. GRB 190202A, Swift-BAT refined analysis
  18. GRB 190202A: Swift/UVOT Detection
  19. GRB 190202A: GOTO optical observations
  20. GRB 190202A: Enhanced Swift-XRT position
  21. GRB 190202A: Koshka Zeiss-1000 optical observations
  22. GRB 190202A: Swift detection of a burst with an optical counterpart
  23. Fermi GBM trigger 570716645/190201517 is not a GRB
  24. GRB 190131A: Insight-HXMT/HE detection
  25. GRB 190129B: Insight-HXMT/HE detection
  26. GRB 190129B: DDOTI Detection of the Possible Afterglow and Suggestion of Fading
  27. GRB 190129B: Swift/UVOT Upper Limits
  28. GRB 190129B: ePESSTO NTT optical observations
  29. GRB 190129B: MASTER Global Robotic Net optical observation
  30. GRB 190129B: GROND possible host candidate
  31. GRB 190129B: Swift-XRT candidate afterglow detection
  32. Fermi GBM Observations of IceCube-190124A
  33. GRB 190129A: Fermi GBM detection
  34. INTEGRAL observation of IceCube-190124A
  35. GRB 190129A: MAXI/GSC detection
  36. Trigger 886496: Another Swift trigger on MAXI J1348-630
  37. Trigger 886486: Swift detection of MAXI J1631-479
  38. Trigger 886266: Another Swift trigger on MAXI J1348-630
  39. GRB 190114C: Optical follow-up from HCT
  40. Swift Trigger 885960: A third Swift trigger on MAXI J1348-630
  41. Trigger 885807: Swift detection of MAXI J1348-630
  42. Search for counterparts to IceCube-190124A with IceCube
  43. Search for counterpart to IceCube-190124A with ANTARES
  44. Fermi-LAT Gamma-ray Observations of IceCube-190124A
  45. GRB 190123A: IKI-GRB-FuN optical upper limit
  46. GRB 190123A: NEXT-0.6m optical limit
  47. GRB 190114C: CHILESCOPE optical observations
  48. GRB 190123A: AROMA-N Optical Observation
  49. GRB 190123A: Swift/UVOT Upper Limits
  50. GRB 190123A: COATLI Optical Observations
  51. GRB 190123A: Swift-BAT refined analysis
  52. GRB 190123A: GMG observational limit
  53. Trigger 885456: Swift detection of MAXI J1631-479
  54. GRB 190123A: Swift-XRT refined Analysis
  55. GRB 190123A: GOTO optical limit
  56. GRB 190123A: Fermi GBM observation
  57. GRB 190123A: Enhanced Swift-XRT position
  58. GRB 190123A: MASTER Global Robotic Net optical observation
  59. GRB 190123A: Swift detection of a burst
  60. GRB 190122A: Fermi GBM observation
  61. GRB 190122A: Fermi-LAT detection
  62. GRB 190114C: RTT150 optical observations
  63. IPN Triangulation of GRB 190118A (long)
  64. IPN Triangulation of GRB 190117A (long)
  65. Trigger 884906: Swift detection of MAXI J1631-479
  66. GRB 190114C: GMRT detection at 1.26GHz
  67. GRB 190114C: MeerKAT radio observation
  68. GRB 190117A: Insight-HXMT/HE detection
  69. Swift ToO Website Down
  70. GRB 190114C: RATIR Optical and NIR Detections
  71. GRB 190114C: RT-22 detection at 36.8 GHz
  72. GRB 190114C: COATLI Optical Detection
  73. GRB 190114C: continued CHILESCOPE optical obs
  74. GRB190114C: ATCA detection of the radio afterglow
  75. GRB 190114B: continued optical observations in Mondy
  76. GRB 190114C: Optical detection from HCT
  77. GRB 190114C: CHILESCOPE optical observations
  78. Konus-Wind observation of GRB 190114C
  79. GRB190114C, Long follow up urged
  80. GRB190114C: GRowth-India detection of optical afterglow
  81. GRB 190114B: Swift-XRT refined Analysis
  82. GRB 190114C: REM optical/NIR detection
  83. GRB 190114C: Mondy optical observations
  84. GRB 190114C: Swift/UVOT Detection
  85. GRB 190114C: Swift-BAT refined analysis
  86. GRB 190114B: Liverpool Telescope near-IR observations
  87. GRB 190114B: optical afterglow observations in Mondy and Abastumani observatories
  88. GRB 190114B, Swift-BAT refined analysis
  89. GRB 190114B: Swift/UVOT Upper Limits
  90. GRB 190114A: Swift/UVOT Observations
  91. GRB 190114A: Mondy optical afterglow detectio
  92. GRB 190114C:Insight-HXMT/HE detection
  93. GRB 190114C: A type 1 BdHN with TeV emission
  94. GRB 190114C: AGILE/MCAL detection
  95. GRB 190114C: Fermi-LAT detection
  96. GRB 190114C: Fermi GBM detection
  97. GRB 190114C: Swift-XRT refined Analysis
  98. GRB 190114C: Enhanced Swift-XRT position
  99. GRB 190114C: GROND detection of the afterglow
  100. GRB 190114C: OASDG optical observations

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