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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"

19596 results found.

  1. GRB 141015A: Enhanced Swift-XRT position
  2. GRB 141015A: Super-LOTIS early observations
  3. GRB 141015A: ISON-NM early optical observations
  4. GRB 141015A: Swift/XRT localization
  5. GRB 141015A: Swift detection of a burst
  6. IPN Triangulation of GRB 141011A (short/hard)
  7. Trigger 614903: Swift detection of IGR J17544-2619
  8. GRB 141005A: iTelescope.Net T21 Optical Observation
  9. GRB 141005A: Additional P60 imaging and afterglow confirmation
  10. GRB 141004A: Fermi GBM observation
  11. GRB 141004A: GROND observations
  12. GRB 141005A: GROND observations
  13. Konus-Wind observation of GRB 141005A
  14. GRB 141004A: Swift-XRT refined Analysis
  15. GRB 141005A: Swift-XRT refined Analysis
  16. GRB 141005A: Swift/UVOT Upper Limits
  17. GRB 141005A: Swift-BAT refined analysis
  18. GRB 141004A: Swift-BAT refined analysis
  19. GRB 141004A: Swift/UVOT Detection
  20. GRB 141005A: Fermi GBM Detection
  21. GRB 141005A: Enhanced Swift-XRT position
  22. GRB 141004A: RATIR Optical Observations
  23. GRB 141005A: P60 probable afterglow deteaction
  24. GRB 141004A: Enhanced Swift-XRT position
  25. GRB 141005A: Swift detection of a burst
  26. GRB 141004A: a long GRB detected by INTEGRAL
  27. GRB 141004A: Swift detection of a burst with an optical counterpart
  28. Swift observations of HD 305560
  29. GRB 140928A: Swift-XRT follow-up observations
  30. Swift possible detection of the Be star HD 305560
  31. GRB 140930B: Gemini South Spectroscopy
  32. GRB 140930B: GROND observations
  33. GRB 140930B Swift-BAT refined analysis
  34. GRB 140930B: Swift/UVOT Upper Limits
  35. Konus-Wind observation of GRB 140930B
  36. GRB 140930B: Swift-XRT refined Analysis
  37. GRB 140930B: Enhanced Swift-XRT position
  38. GRB 140930B: Prompt enhanced Swift-XRT position
  39. GRB 140930B: MASTER early optical observations
  40. GRB 140930B: Swift detection of a short burst
  41. IPN Triangulation of GRB 140928A
  42. GRB 140928A: Fermi GBM detection
  43. GRB 140928A: GROND Afterglow Candidate
  44. GRB 140928A: Swift-XRT observations
  45. GRB 140928A: Fermi-LAT detection
  46. GRB 140927A: Swift-UVOT analysis
  47. GRB 140927A: Swift-BAT refined analysis
  48. GRB 140927A: Swift-XRT refined Analysis
  49. GRB 140927A: Enhanced Swift-XRT position
  50. GRB 140927A: Swift detection of a burst
  51. Swift Trigger 613581 is not an astrophysical event
  52. Swift Trigger 613516 is not an astrophysical event
  53. GRB 140919A, Swift-BAT refined analysis
  54. GRB 140919A: Swift-XRT refined Analysis
  55. GRB 140919A: Swift/UVOT Detection
  56. GRB 140919A: GROND afterglow candidate
  57. GRB 140919A: Fermi GBM observation
  58. GRB 140919A: Enhanced Swift-XRT position
  59. GRB 140919A: Swift/UVOT observations
  60. GRB 140919A: Swift-XRT observations
  61. GRB 140919A: Swift detection of a burst
  62. Swift detection of outburst from 4U 1700+24
  63. GRB 140916A: Swift/UVOT Upper Limits
  64. GRB 140916A: Swift-BAT refined analysis
  65. GRB 140916A: UKIRT J-band observations
  66. GRB 140916A: Swift-XRT refined Analysis
  67. GRB 140916A: Enhanced Swift-XRT position
  68. GRB 140916A: FTS observations
  69. GRB 140916A: Prompt enhanced Swift-XRT position
  70. GRB 140916A: Swift detection of a burst
  71. GRB 140907A: Continued DCT Observations
  72. GRB 140909A: Confirmation of the Swift-XRT afterglow
  73. GRB 140907A: Mondy optical observations
  74. GRB 140909A: Swift/UVOT Upper Limits
  75. GRB 140909A: Swift-XRT observations
  76. GRB 140907A: TShAO observations
  77. GRB 140909A: Swift detection of a GRB
  78. GRB 140907A: MASTER optical observations
  79. Refined IPN Triangulation of GRB 140906C
  80. IPN Triangulation of GRB 140906C (short/hard)
  81. GRB 140907A: T100 observations
  82. GRB 140907A: Swift-BAT refined analysis
  83. GRB 140907A: Fermi GBM Detection
  84. GRB 140907A: Swift-XRT refined Analysis
  85. GRB 140907A: Enhanced Swift-XRT position
  86. GRB140907A: Swift UVOT detection
  87. GRB 140907A: Swift detection of a burst with an optical counterpart
  88. GRB 140903A: Confirmation of Optical Fading from Discovery Channel Telescope
  89. GRB 140901B: Swift XRT observation
  90. GRB 140903A: FTN observations
  91. GRB 140818B: TShAO optical upper limit
  92. GRB 140903A: MAXI/GSC upper limit
  93. GRB 140901B: Fermi GBM detection
  94. GRB 140901B found in ground analysis of BAT data
  95. GRB 140903A: Swift/UVOT Upper Limits
  96. GRB 140903A: Swift-BAT Spectral lag analysis
  97. GRB 140903A: P60 Optical Observations
  98. GRB140903A: Discovery Channel Telescope Optical Detection
  99. GRB 140903A: Swift-BAT refined analysis
  100. GRB 140903A: Swift-XRT refined Analysis

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Download all Circulars as a .tar.gz archive (updated once a day):
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