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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').
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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"

24784 results found.

  1. GRB 170607B: Fermi GBM detection
  2. GRB 170607A: ISON/Terskol optical observations
  3. LIGO/Virgo G288732: GWFUNC/NOWT observations of the skymap and follow-up of the Fermi/LAT candidate
  4. LIGO/Virgo G288732: Swift/UVOT follow up of the possible LAT counterpart
  5. LIGO/Virgo G288732: Swift/BAT data search
  6. LIGO/Virgo G288732: Swift-XRT follow up of the putative LAT counterpart
  7. LIGO/Virgo G288732: INTEGRAL search for a prompt gamma-ray counterpart
  8. LIGO/Virgo G288732:SVOM/Mini-GWAC observations of the initial skymap
  9. LIGO/Virgo G288732: AGILE GRID Observations
  10. LIGO/Virgo G288732: Fermi-LAT detection of a weak candidate
  11. LIGO/Virgo G288732: IceCube neutrino observations update
  12. LIGO/Virgo G288732: AGILE MCAL Observations
  13. LIGO/Virgo G288732 ANTARES search
  14. LIGO/VIRGO G288732: Fermi GBM Observations
  15. GRB 170607A: Swift/UVOT Detection
  16. GRB 170607A: Fermi GBM observation
  17. GRB 170607A: NOT optical afterglow detection
  18. GRB 170607A: Swift-XRT refined Analysis
  19. GRB 170607A: Enhanced Swift-XRT position
  20. GRB 170607A: Swift detection of a burst with a bright optical counterpart
  21. GRB 170531B: Zeiss-1000/CrAO optical observations
  22. GRB 170531B: WHT spectroscopy
  23. GRB 170519A: TShAO and AbAO optical observations
  24. GRB 170604A: Swift/UVOT Observations
  25. GRB 170519A: Mondy optical observations
  26. GRB 170604A: RATIR Optical and NIR Observations
  27. GRB 170604A: AbAO optical observations
  28. Swift trigger 755873: Swift BAT and XRT refined analysis
  29. GRB 170522A: confirmation of the X-ray afterglow
  30. GROND observations of GRB170604A
  31. GRB 170604A: Swift-XRT refined Analysis
  32. GRB 170604A: GTC spectroscopic redshift
  33. GRB 170604A: Enhanced Swift-XRT position
  34. GRB 170604A: Swift-BAT refined analysis
  35. Swift Trigger 755873: a possible GRB
  36. GRB 170604A: optical observations
  37. GRB 170604A: Swift detection of a burst
  38. GRB 170531B: ISON/Terskol optical observations
  39. GRB 170531B: Swift/UVOT Detection
  40. GRB 170531B: SMARTS optical/IR observations
  41. GRB 170531B: Swift-BAT refined analysis
  42. GRB 170531A: Swift/UVOT Upper Limits
  43. GRB 170531B: LCO observations
  44. GRB 170531B: Swift-XRT refined Analysis
  45. GRB 170531A: Swift-XRT refined Analysis
  46. GROND observations of GRB 170531B
  47. GRB 170531B: Redshift from GTC/OSIRIS
  48. GRB 170531B: Enhanced Swift-XRT position
  49. GRB 170531B: CrAO confirmation of the afterglow
  50. GRB 170531B: Swift detection of a burst
  51. GRB 170531A: Swift detection of a burst
  52. GRB 170519A: CrAO optical observations
  53. GRB 170524B: Swift-UVOT/XRT Confirmation of Afterglow
  54. IPN Triangulation of GRB 170529A (long)
  55. GRB 170519A: ISON/Multa optical observations
  56. GRB 170511A: Fermi GBM observation
  57. LIGO/Virgo G268556: optical observations and classification of Pan-STARRS1 transients
  58. LIGO/Virgo G268556/GW170104: Konus-Wind observations
  59. GRB 170527A: Fermi GBM detection
  60. GRB 170526A, Swift-BAT refined analysis
  61. GRB 170526A: Swift/UVOT Upper Limits
  62. GRB 170526A: Swift-XRT refined Analysis
  63. LIGO/Virgo G268556: VERITAS Very-High-Energy Gamma-Ray Observations
  64. GRB 170524A: RATIR Optical and NIR Observations
  65. GRB 170526A: Enhanced Swift-XRT position
  66. GRB 170524B: Swift-XRT observations
  67. GRB 170526A: Swift detection of a burst
  68. GRB 170524A: TSHAO and CrAO optical observations
  69. GRB 170524A: Swift-BAT refined analysis
  70. GRB 170524B: Swift detection of a burst
  71. GRB 170524A: Swift/UVOT Upper Limits
  72. IPN Triangulation of GRB 170522A
  73. GRB 170524A: Enhanced Swift-XRT position
  74. GRB 170524A: Swift detection of a burst (or possible new SGR)
  75. GRB 170522A: LCO McDonald observations
  76. GRB 170522A: Swift-XRT observations
  77. GRB 170522A: Global MASTER-Net job
  78. GRB 170522A: Fermi GBM detection
  79. GRB 170514A CALET Gamma-Ray Burst Monitor detection
  80. GRB 170519A: Watcher optical observations
  81. GRB 170519A: Continued RATIR Optical and NIR Observations
  82. GRB 170519A: MITSuME Okayama Optical Observation
  83. GRB 170519A: NOT optical observations
  84. GRB170519A, Swift-UVOT Detection
  85. GRB 170519A: KAIT Optical Observations
  86. GRB 170519A: Swift-XRT refined Analysis
  87. GRB 170519A: Swift-BAT refined analysis
  88. GRB 170519A: Weihai optical observations
  89. GRB 170510A: LCO Siding Springs early observations
  90. GRB 170519A: RATIR Optical and NIR Observations
  91. GRB 170519A: optical observations
  92. GRB 170519A: Enhanced Swift-XRT position
  93. GRB 170519A: Swift detection of a burst with an optical counterpart
  94. LIGO/Virgo G277583: UH88/SNIFS classification of ATLAS and PS1 transients
  95. GRB 170510A: Swift-XRT afterglow detection
  96. GRB 170516A: Swift-BAT refined analysis
  97. GRB 170516A: Swift-XRT refined Analysis
  98. GRB 170516A: Swift/UVOT Upper Limits
  99. GRB 170516A: Enhanced Swift-XRT position
  100. GRB 170516A: Swift detection of a burst

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