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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"

19549 results found.

  1. LIGO/Virgo G275697: Further Swift-XRT sources
  2. LIGO/Virgo G275697: SVOM/Mini-GWAC observations of the initial skymap
  3. LIGO/Virgo G275404: A near-infrared transient in the error circle of AGL J1914+1043
  4. LIGO/Virgo G275697: CALET Observations
  5. LIGO/Virgo G275697: MASTER automatic follow up detection
  6. LIGO/Virgo G275404: Nearby galaxy observations by J-GEM collaboration
  7. LIGO/Virgo G275697: Fermi-LAT search for a high-energy gamma-ray counterpart
  8. LIGO/Virgo G275697: Swift/BAT data search
  9. LIGO/Virgo G275697: INTEGRAL search for a prompt gamma-ray counterpart
  10. LIGO/VIRGO G275697: Fermi GBM Observations
  11. LIGO/Virgo G275697 ANTARES search
  12. LIGO/Virgo G275404: Fermi-LAT search for a high-energy gamma-ray counterpart
  13. LIGO/Virgo G275404: INTEGRAL search for a prompt gamma-ray counterpart
  14. LIGO/Virgo G275404: AGILE-GRID detection of a possible gamma-ray transient
  15. LIGO/Virgo G275404 ANTARES search
  16. LIGO/Virgo G275404: Swift/BAT data search
  17. LIGO/Virgo G275404: SVOM/Mini-GWAC: Observations of initial skymap
  18. LIGO/Virgo G274296: Swift/BAT data search
  19. LIGO/Virgo G275404: Fermi GBM Observations
  20. LIGO/Virgo G274296: Liverpool Telescope classification of EM candidates
  21. LIGO/Virgo G274296: MASTER new OT
  22. LIGO/Virgo G274296: CALET Observations
  23. LIGO/Virgo G274296: HAWC follow-up
  24. GRB 170222A: Tiled Swift observations
  25. GRB 170222A: Swift ToO observations
  26. LIGO/Virgo G274296: PIRATE Observations
  27. IPN Triangulation of GRB 170222A (short/hard)
  28. LIGO/Virgo G274296: J-GEM optical/NIR follow-up observations
  29. Swift Trigger 739517 is probably not a GRB
  30. LIGO/Virgo G274296: Asiago 1.82m Optical Observations
  31. LIGO/Virgo G274296: MASTER new bright possible SN detection and inspection dinamic
  32. LIGO/Virgo G274296: PESSTO classification of 9 Pan-STARRS transients
  33. LIGO/Virgo G274296: Fermi-LAT search for a high-energy gamma-ray counterpart
  34. LIGO/Virgo G274296 ANTARES search
  35. LIGO/Virgo G274296: Optical Observation
  36. LIGO/Virgo G274296: Pan-STARRS imaging and discovery of 70 transients
  37. LIGO/Virgo G274296: Observations of initial skymap by project Mini-GWAC of SVOM
  38. LIGO/Virgo G274296: INTEGRAL search for a prompt gamma-ray counterpart
  39. LIGO/VIRGO G274296: Fermi GBM Observations
  40. GRB 170214A: Swift-XRT afterglow detection
  41. Trigger 738728: Swift triggered on noise near NGC 4096
  42. GRB 170214A: Mondy optical upper limit
  43. GRB170214A: RATIR Optical and NIR Afterglow Confirmation
  44. GRB 170214A: GROND detection in all bands
  45. GRB 170214A: Swift/UVOT Upper Limits
  46. GRB170214A: RATIR Optical and NIR Observations
  47. GRB 170209A: GROND confirmation of MASTER afterglow
  48. GRB 170214A: Swift ToO observations
  49. GRB 170208B: IRSF upper limits
  50. GRB 170208A: IRSF upper limits
  51. GRB 170209A: Swift-XRT observations
  52. IPN Triangulation of GRB 170210A
  53. GRB 170209A: Swift ToO observations
  54. GRB 170208B: Swift/UVOT Upper Limits
  55. GRB 170208B: RATIR Optical and NIR Observations
  56. GRB 170208A: Swift-BAT refined analysis
  57. Fermi Trigger 508295323: MASTER-OAFA possible OT detection
  58. GRB 170208A: Swift-XRT refined Analysis
  59. GRB 170208B WHT nIR candidate afterglow
  60. GRB 170208A: Swift/UVOT Upper Limits
  61. Konus-Wind observation of GRB 170208B
  62. Konus-Wind observation of GRB 170208A
  63. GRB 170208B: GROND observations
  64. GRB 170208B: NOT upper limits
  65. GRB 170208B: Etelman observatory optical observations
  66. GRB 170208B: Enhanced Swift-XRT position
  67. GRB 170208A: Enhanced Swift-XRT position
  68. GRB 170208B: Swift detection of a burst
  69. GRB 170208A: Swift detection of a burst
  70. IPN Triangulation of GRB 170207A (long/very bright)
  71. GRB 170206B: Swift/UVOT Upper Limits
  72. GRB 170206B: Swift-XRT refined Analysis
  73. GRB 170206B: Enhanced Swift-XRT position
  74. GRB 170206B: Swift detection of a burst
  75. GRB 170205A: Swift/UVOT Detection of a Fading Afterglow
  76. GRB 170205A: NOT afterglow observations
  77. GRB 170205A: Enhanced Swift-XRT position
  78. GRB 170205A: RATIR Optical and NIR Observations
  79. GRB 170202A: SMARTS optical/IR afterglow observations
  80. GRB 170205A: Swift detection of a burst with an optical counterpart
  81. GRB 170202A: Zadko observatory - Gingin optical observations
  82. GRB 170202A: Etelman Observatory optical observations
  83. GRB 170202A: RATIR Optical and NIR Observations
  84. GRB 170202A: SQUEAN Observation
  85. GRB 170202A: T100 observations
  86. GRB 170202A: Swift/UVOT Detection
  87. GRB 170202A: Enhanced Swift-XRT position
  88. GRB 170202A: NOT afterglow observations
  89. GRB 170202A: Zadko observatory - Gingin optical observations
  90. GRB 170202A: MASTGlobal ER-Net bright OT nonmonotonic light curve
  91. GRB 170202A: Mini-MegaTORTORA upper limits
  92. GRB 170202A: Swift detection of a burst with an optical afterglow
  93. GRB 170131A: Swift/UVOT Upper Limits
  94. GRB 170131A: Swift ToO observations
  95. GRB 170127B: Swift-BAT refined analysis
  96. GRB 170127C: Swift-XRT observations
  97. GRB 170127A: GROND Upper limits
  98. GRB 170124A: CALET Gamma-Ray Burst Monitor detection
  99. GRB 170127B: Swift/UVOT Upper Limits
  100. GRB 170127A: Swift/UVOT Upper Limits

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