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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"

27041 results found.

  1. GRB 141015A: Swift-XRT afterglow confirmation and refined Analysis
  2. GRB 141017A: Swift/UVOT Detection
  3. GRB 141017A: Swift-XRT refined Analysis
  4. GRB 141017A: Zadko observatory - Gingin optical observations
  5. GRB 141017A: Swift detection of a burst
  6. GRB 141015A: Swift/UVOT Upper Limits
  7. GRB 141015A: Swift-BAT refined analysis
  8. GRB 141015A: LCO-McDonald observations
  9. GRB 141015A: RATIR Optical Upper Limits
  10. GRB 141015A: Super-LOTIS early observations
  11. GRB 141015A: Swift/XRT localization
  12. GRB 141015A: Swift detection of a burst
  13. Fermi Gamma-ray Burst Monitor trigger 141014781 is not a GRB
  14. IPN Triangulation of GRB 141011A (short/hard)
  15. GRB 141011A: Fermi GBM detection
  16. Trigger 614903: Swift detection of IGR J17544-2619
  17. GRB 141005A: iTelescope.Net T21 Optical Observation
  18. GRB 141005A: Additional P60 imaging and afterglow confirmation
  19. GRB 141004A: Fermi GBM observation
  20. GRB 141004A: GROND observations
  21. GRB 141005A: GROND observations
  22. Konus-Wind observation of GRB 141005A
  23. GRB 141004A: Swift-XRT refined Analysis
  24. GRB 141005A: Swift-XRT refined Analysis
  25. GRB 141005A: Swift/UVOT Upper Limits
  26. GRB 141005A: Swift-BAT refined analysis
  27. GRB 141004A: Swift-BAT refined analysis
  28. GRB141004A: NOT imaging and spectroscopy
  29. GRB 141004A: Swift/UVOT Detection
  30. GRB 141005A: Fermi GBM Detection
  31. GRB 141004A: RATIR Optical Observations
  32. GRB 141004A: Monte Agliale Observatory optical observations
  33. GRB 141005A: RATIR Optical Observations
  34. GRB 141005A: P60 probable afterglow deteaction
  35. GRB 141005A: Swift detection of a burst
  36. GRB 141004A: Swift detection of a burst with an optical counterpart
  37. Swift observations of HD 305560
  38. GRB 140928A: Swift-XRT follow-up observations
  39. GRB 140930B: MASTER early possible OT detection
  40. Swift possible detection of the Be star HD 305560
  41. GRB 140930B: Gemini South Spectroscopy
  42. GRB 140930B: GROND observations
  43. GRB 140930A/MAXI J2259+524: MASTER optical observations
  44. GRB 140930B Swift-BAT refined analysis
  45. GRB 140930B: Swift/UVOT Upper Limits
  46. GRB 140930B: Swift-XRT refined Analysis
  47. GRB 140928A: MAXI-GSC detection
  48. GRB 140930B: ISON-Kislovodsk observations
  49. GRB 140930B: MASTER early optical observations
  50. GRB 140930B: Swift detection of a short burst
  51. GRB 140928A: LCO-Cerro Tololo further observations
  52. IPN Triangulation of GRB 140928A
  53. GRB 140928A: LCO-Cerro Tololo observations
  54. GRB 140928A: Fermi GBM detection
  55. GRB 140928A: GROND Afterglow Candidate
  56. GRB 140928A: Swift-XRT observations
  57. GRB 140928A: Fermi-LAT detection
  58. GRB 140927A: Swift-BAT refined analysis
  59. GRB 140927A: Swift-XRT refined Analysis
  60. GRB 140927A: Swift detection of a burst
  61. Swift Trigger 613581 is not an astrophysical event
  62. Swift Trigger 613516 is not an astrophysical event
  63. GRB 140919A, Swift-BAT refined analysis
  64. GRB 140919A: Swift-XRT refined Analysis
  65. GRB 140919A: Swift/UVOT Detection
  66. GRB 140919A: GROND afterglow candidate
  67. GRB 140919A: Fermi GBM observation
  68. GRB 140919A: Swift/UVOT observations
  69. GRB 140919A: Swift-XRT observations
  70. GRB 140919A: Swift detection of a burst
  71. Swift detection of outburst from 4U 1700+24
  72. GRB 140916A: Swift/UVOT Upper Limits
  73. GRB 140916A: Swift-BAT refined analysis
  74. GRB 140916A: Swift-XRT refined Analysis
  75. GRB 140916B: iPTF Optical Observations
  76. GRB 140916A: FTS observations
  77. GRB 140916A: Swift detection of a burst
  78. GRB 140907A: Continued DCT Observations
  79. Fermi GBM trigger 140913075 is not a GRB
  80. GRB 140909A: Confirmation of the Swift-XRT afterglow
  81. GRB 140903A: Chandra detection of the afterglow
  82. GRB 140909A: Swift/UVOT Upper Limits
  83. GRB 140909A: Swift-XRT observations
  84. GRB 140907A: MASTER optical observations
  85. GRB 140907A: T100 observations
  86. GRB 140907A: Swift-BAT refined analysis
  87. GRB 140907A: Fermi GBM Detection
  88. GRB 140907A: Swift-XRT refined Analysis
  89. GRB140907A: Swift UVOT detection
  90. GRB 140906B: Fermi GBM Detection of a Long GRB
  91. GRB 140907A: Swift detection of a burst with an optical counterpart
  92. GRB 140906A - Fermi GBM Detection
  93. GRB 140906A: iPTF optical transient candidates
  94. GRB 140903A: Confirmation of Optical Fading from Discovery Channel Telescope
  95. GRB 140903A: Possible optical variability
  96. GRB 140903A: NOT optical and NIR observations
  97. GRB 140901B: Swift XRT observation
  98. GRB 140903A: FTN observations
  99. GRB 140903A: MAXI/GSC upper limit
  100. GRB 140901B: Fermi GBM detection

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