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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"

24770 results found.

  1. GRB 170607A: Swift/UVOT Detection
  2. GRB 170607A: Fermi GBM observation
  3. GRB 170607A: NOT optical afterglow detection
  4. GRB 170607A: Swift-XRT refined Analysis
  5. GRB 170607A: Enhanced Swift-XRT position
  6. GRB 170607A: Swift detection of a burst with a bright optical counterpart
  7. GRB 170531B: Zeiss-1000/CrAO optical observations
  8. GRB 170531B: WHT spectroscopy
  9. GRB 170519A: TShAO and AbAO optical observations
  10. GRB 170604A: Swift/UVOT Observations
  11. GRB 170519A: Mondy optical observations
  12. GRB 170604A: RATIR Optical and NIR Observations
  13. GRB 170604A: AbAO optical observations
  14. Swift trigger 755873: Swift BAT and XRT refined analysis
  15. GRB 170522A: confirmation of the X-ray afterglow
  16. GROND observations of GRB170604A
  17. GRB 170604A: Swift-XRT refined Analysis
  18. GRB 170604A: GTC spectroscopic redshift
  19. GRB 170604A: Enhanced Swift-XRT position
  20. GRB 170604A: Swift-BAT refined analysis
  21. Swift Trigger 755873: a possible GRB
  22. GRB 170604A: optical observations
  23. GRB 170604A: Swift detection of a burst
  24. GRB 170531B: ISON/Terskol optical observations
  25. GRB 170531B: Swift/UVOT Detection
  26. GRB 170531B: SMARTS optical/IR observations
  27. GRB 170531B: Swift-BAT refined analysis
  28. GRB 170531A: Swift/UVOT Upper Limits
  29. GRB 170531B: LCO observations
  30. GRB 170531B: Swift-XRT refined Analysis
  31. GRB 170531A: Swift-XRT refined Analysis
  32. GROND observations of GRB 170531B
  33. GRB 170531B: Redshift from GTC/OSIRIS
  34. GRB 170531B: Enhanced Swift-XRT position
  35. GRB 170531B: CrAO confirmation of the afterglow
  36. GRB 170531B: Swift detection of a burst
  37. GRB 170531A: Swift detection of a burst
  38. GRB 170519A: CrAO optical observations
  39. GRB 170524B: Swift-UVOT/XRT Confirmation of Afterglow
  40. IPN Triangulation of GRB 170529A (long)
  41. GRB 170519A: ISON/Multa optical observations
  42. GRB 170511A: Fermi GBM observation
  43. LIGO/Virgo G268556: optical observations and classification of Pan-STARRS1 transients
  44. LIGO/Virgo G268556/GW170104: Konus-Wind observations
  45. GRB 170527A: Fermi GBM detection
  46. GRB 170526A, Swift-BAT refined analysis
  47. GRB 170526A: Swift/UVOT Upper Limits
  48. GRB 170526A: Swift-XRT refined Analysis
  49. LIGO/Virgo G268556: VERITAS Very-High-Energy Gamma-Ray Observations
  50. GRB 170524A: RATIR Optical and NIR Observations
  51. GRB 170526A: Enhanced Swift-XRT position
  52. GRB 170524B: Swift-XRT observations
  53. GRB 170526A: Swift detection of a burst
  54. GRB 170524A: TSHAO and CrAO optical observations
  55. GRB 170524A: Swift-BAT refined analysis
  56. GRB 170524B: Swift detection of a burst
  57. GRB 170524A: Swift/UVOT Upper Limits
  58. IPN Triangulation of GRB 170522A
  59. GRB 170524A: Enhanced Swift-XRT position
  60. GRB 170524A: Swift detection of a burst (or possible new SGR)
  61. GRB 170522A: LCO McDonald observations
  62. GRB 170522A: Swift-XRT observations
  63. GRB 170522A: Global MASTER-Net job
  64. GRB 170522A: Fermi GBM detection
  65. GRB 170514A CALET Gamma-Ray Burst Monitor detection
  66. GRB 170519A: Watcher optical observations
  67. GRB 170519A: Continued RATIR Optical and NIR Observations
  68. GRB 170519A: MITSuME Okayama Optical Observation
  69. GRB 170519A: NOT optical observations
  70. GRB170519A, Swift-UVOT Detection
  71. GRB 170519A: KAIT Optical Observations
  72. GRB 170519A: Swift-XRT refined Analysis
  73. GRB 170519A: Swift-BAT refined analysis
  74. GRB 170519A: Weihai optical observations
  75. GRB 170510A: LCO Siding Springs early observations
  76. GRB 170519A: RATIR Optical and NIR Observations
  77. GRB 170519A: optical observations
  78. GRB 170519A: Enhanced Swift-XRT position
  79. GRB 170519A: Swift detection of a burst with an optical counterpart
  80. LIGO/Virgo G277583: UH88/SNIFS classification of ATLAS and PS1 transients
  81. GRB 170510A: Swift-XRT afterglow detection
  82. GRB 170516A: Swift-BAT refined analysis
  83. GRB 170516A: Swift-XRT refined Analysis
  84. GRB 170516A: Swift/UVOT Upper Limits
  85. GRB 170516A: Enhanced Swift-XRT position
  86. GRB 170516A: Swift detection of a burst
  87. Swift Trigger AXP CXOU J164710.2-455216: MASTER-OAFA observations
  88. Swift Trigger on AXP CXOU J164710.2-455216
  89. GRB 170514A: Fermi GBM detection
  90. GRB 170510A: Global MASTER Net possible OT observations
  91. LIGO/Virgo G284239: Konus-Wind observations
  92. GRB 170510A: LCO possible counterpart
  93. GRB 170510A: Swift-XRT observations
  94. GRB 170510A: Fermi GBM observation
  95. LIGO/Virgo G284239: H.E.S.S. very-high energy gamma-ray follow-up
  96. LIGO/Virgo G284239: MAXI/GSC observations
  97. Swift Trigger 752193 is not a GRB
  98. LIGO/Virgo G284239: AstroSat CZTI upper limits
  99. GRB 170423A: TAROT Reunion observatory optical observations
  100. Swift XRT observations of GRB 170424A

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