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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"

24807 results found.

  1. GRB 170626A: OASDG optical observations
  2. GRB 170626A: Swift-BAT refined analysis
  3. GRB 170626A: TNG optical observations
  4. GRB 170626A: Afterglow detection from 1.5m OSN
  5. GRB 170626A: SAO RAS possible OT detection
  6. GRB 170626A: Swift-XRT refined Analysis
  7. GRB 170626A: Fermi GBM observation
  8. GRB 170626B: The first GRB detected by the Insight-HXMT X-ray Telescope (revised)
  9. GRB 170626A: Swift detection of a burst
  10. LIGO/Virgo G288732: Fermi GBM Upper Limits for the LIGO Trigger and LAT Candidate
  11. Swift trigger 758168 is probably not an astrophysical source
  12. Swift Trigger 758005 is Probably Not an Astrophysical Source
  13. GRB 170614A CALET Gamma-Ray Burst Monitor detection
  14. Swift Trigger 756953 is probably not an astrophysical source
  15. GRB170612.87 MASTER-Net OT detection
  16. LIGO/Virgo G288732: Kiso/KWFC optical imaging of the possible Fermi/LAT counterpart
  17. LIGO/Virgo G288732: HAWC follow-up
  18. Konus-Wind observation of GRB 170604A
  19. LIGO/Virgo G288732: UKIRT near-IR imaging of the Fermi/LAT candidate
  20. LIGO/Virgo G288732: LBT optical imaging of the Fermi/LAT candidate
  21. GRB 170610A: MAXI/GSC detection
  22. LIGO/Virgo G288732 : MAXI/GSC observations
  23. GRB 170607A: Redshift from GTC/OSIRIS
  24. GRB 170607B: Fermi GBM detection
  25. GRB 170607A: ISON/Terskol optical observations
  26. LIGO/Virgo G288732: GWFUNC/NOWT observations of the skymap and follow-up of the Fermi/LAT candidate
  27. LIGO/Virgo G288732: Swift/UVOT follow up of the possible LAT counterpart
  28. LIGO/Virgo G288732: Swift/BAT data search
  29. LIGO/Virgo G288732: Swift-XRT follow up of the putative LAT counterpart
  30. LIGO/Virgo G288732: INTEGRAL search for a prompt gamma-ray counterpart
  31. LIGO/Virgo G288732:SVOM/Mini-GWAC observations of the initial skymap
  32. LIGO/Virgo G288732: AGILE GRID Observations
  33. LIGO/Virgo G288732: Fermi-LAT detection of a weak candidate
  34. LIGO/Virgo G288732: IceCube neutrino observations update
  35. LIGO/Virgo G288732: AGILE MCAL Observations
  36. LIGO/Virgo G288732 ANTARES search
  37. LIGO/VIRGO G288732: Fermi GBM Observations
  38. GRB 170607A: Swift/UVOT Detection
  39. GRB 170607A: Fermi GBM observation
  40. GRB 170607A: NOT optical afterglow detection
  41. GRB 170607A: Swift-XRT refined Analysis
  42. GRB 170607A: Enhanced Swift-XRT position
  43. GRB 170607A: Swift detection of a burst with a bright optical counterpart
  44. GRB 170531B: Zeiss-1000/CrAO optical observations
  45. GRB 170531B: WHT spectroscopy
  46. GRB 170519A: TShAO and AbAO optical observations
  47. GRB 170604A: Swift/UVOT Observations
  48. GRB 170519A: Mondy optical observations
  49. GRB 170604A: RATIR Optical and NIR Observations
  50. GRB 170604A: AbAO optical observations
  51. Swift trigger 755873: Swift BAT and XRT refined analysis
  52. GRB 170522A: confirmation of the X-ray afterglow
  53. GROND observations of GRB170604A
  54. GRB 170604A: Swift-XRT refined Analysis
  55. GRB 170604A: GTC spectroscopic redshift
  56. GRB 170604A: Enhanced Swift-XRT position
  57. GRB 170604A: Swift-BAT refined analysis
  58. Swift Trigger 755873: a possible GRB
  59. GRB 170604A: optical observations
  60. GRB 170604A: Swift detection of a burst
  61. GRB 170531B: ISON/Terskol optical observations
  62. GRB 170531B: Swift/UVOT Detection
  63. GRB 170531B: SMARTS optical/IR observations
  64. GRB 170531B: Swift-BAT refined analysis
  65. GRB 170531A: Swift/UVOT Upper Limits
  66. GRB 170531B: LCO observations
  67. GRB 170531B: Swift-XRT refined Analysis
  68. GRB 170531A: Swift-XRT refined Analysis
  69. GROND observations of GRB 170531B
  70. GRB 170531B: Redshift from GTC/OSIRIS
  71. GRB 170531B: Enhanced Swift-XRT position
  72. GRB 170531B: CrAO confirmation of the afterglow
  73. GRB 170531B: Swift detection of a burst
  74. GRB 170531A: Swift detection of a burst
  75. GRB 170519A: CrAO optical observations
  76. GRB 170524B: Swift-UVOT/XRT Confirmation of Afterglow
  77. IPN Triangulation of GRB 170529A (long)
  78. GRB 170519A: ISON/Multa optical observations
  79. GRB 170511A: Fermi GBM observation
  80. LIGO/Virgo G268556: optical observations and classification of Pan-STARRS1 transients
  81. LIGO/Virgo G268556/GW170104: Konus-Wind observations
  82. GRB 170527A: Fermi GBM detection
  83. GRB 170526A, Swift-BAT refined analysis
  84. GRB 170526A: Swift/UVOT Upper Limits
  85. GRB 170526A: Swift-XRT refined Analysis
  86. LIGO/Virgo G268556: VERITAS Very-High-Energy Gamma-Ray Observations
  87. GRB 170524A: RATIR Optical and NIR Observations
  88. GRB 170526A: Enhanced Swift-XRT position
  89. GRB 170524B: Swift-XRT observations
  90. GRB 170526A: Swift detection of a burst
  91. GRB 170524A: TSHAO and CrAO optical observations
  92. GRB 170524A: Swift-BAT refined analysis
  93. GRB 170524B: Swift detection of a burst
  94. GRB 170524A: Swift/UVOT Upper Limits
  95. IPN Triangulation of GRB 170522A
  96. GRB 170524A: Enhanced Swift-XRT position
  97. GRB 170524A: Swift detection of a burst (or possible new SGR)
  98. GRB 170522A: LCO McDonald observations
  99. GRB 170522A: Swift-XRT observations
  100. GRB 170522A: Global MASTER-Net job

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