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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"

19603 results found.

  1. GRB 110827A: Swift detection of a burst
  2. GRB110825A: Swift target of opportunity observation
  3. IPN triangulation of GRB110825A (very intense, long-duration)
  4. Swift-BAT Trigger 501485 is noise
  5. Swift-BAT refined analysis of SFXT IGR J08408-4503 (trigger 501368)
  6. Swift J1834.9-0846: Precise X-ray Position and the Confirmation of its Spin Period
  7. IPN triangulation of GRB 110820B (very long duration, extremely intense)
  8. GRB 110820A: Swift/UVOT Upper Limits
  9. GRB 110820A: Swift-XRT refined Analysis
  10. GRB 110820A: Swift-BAT refined analysis
  11. GRB 110820A: Enhanced Swift-XRT position
  12. GRB 110820A: CrAO optical upper limit
  13. GRB 110820A: MASTER-NET observations
  14. GRB 110820A: Swift detection of a burst
  15. GRB 110818A: Fermi GBM observation
  16. GRB 110818A: Swift/UVOT Upper Limits
  17. GRB 110818A: Enhanced Swift-XRT position
  18. GRB 110818A: Swift-XRT refined Analysis
  19. GRB 110815A: Swift-XRT and UVOT refined Analysis
  20. GRB 110818A, Swift-BAT refined analysis
  21. GRB 110818A: Swift detection of a burst
  22. IPN triangulation of GRB110815A (long, intense)
  23. GRB 110801A: Konus-Wind and Swift/BAT joint spectral analysis
  24. GRB 110801A: optical observations at Mt. Terskol observatory
  25. Reprocessed enhanced Swift-XRT positions and GRB products: update
  26. SGR 1834.9-0846/ GRB 110807A, I-band observations
  27. IPN triangulation of GRB 110808B (short/hard/intense)
  28. RXTE Discovery of the Spin Period of Swift J1834.9-0846
  29. GRB 110808A: Swift/UVOT Detection
  30. Swift Trigger 458942 is probably not a burst
  31. GRB 110808A: Swift-BAT refined analysis
  32. GRB 110808A: Swift-XRT refined Analysis
  33. SGR J1834.9-0846: A Neutron Star in W41?
  34. Swift SGR 1834.9-0846: Swift-BAT refined analysis
  35. GRB 110808A: Enhanced Swift-XRT position
  36. GRB 110808A: Swift detection of a burst with optical counterpart
  37. Fermi GBM detection of a SGR-like burst
  38. GRB 110807A: Swift detection of a burst or a posible new SGR
  39. GRB 110726A: two epochs of SAO RAS optical observations
  40. Reprocessed enhanced Swift-XRT positions and GRB products
  41. IPN triangulation of GRB110802A (short/hard burst)
  42. GRB 110731A : Suzaku WAM observation of the prompt emission
  43. GRB 110726A: Swift-XRT refined Analysis
  44. GRB110731A: MOA optical observations of the steeply fading afterglow
  45. GRB 110801A: MASTER OT observations
  46. GRB 110801A: Swift-BAT refined analysis
  47. Swift/UVOT observations of GRB110801A
  48. GRB 110801A: Swift-XRT refined Analysis
  49. GRB 110801A: Enhanced Swift-XRT position
  50. GRB 110801A: ROTSE-III Detection of re-brightening from OT
  51. GRB 110801A: Swift detection of a burst with an optical counterpart
  52. GRB 110731A / EVLA upper limits
  53. GRB 110731A: Swift-XRT refined Analysis
  54. Konus-Wind observation of GRB 110731A
  55. GRB110731A: Swift/UVOT Observations
  56. GRB 110731A: Fermi GBM observation
  57. GRB 110731A: Enhanced Swift-XRT position
  58. Fermi-LAT Detection of GRB110731A
  59. GRB 110731A: Swift-BAT refined analysis
  60. GRB 110731A: FTN+FTS afterglow observations
  61. GRB 110731A: Swift detection of a burst with an optical counterpart
  62. GRB 110721A: Swift observations of afterglow candidate
  63. AXP 4U 0142+61: Swift-BAT refined analysis
  64. GRB 110726A: optical upper limit in CrAO
  65. Swift detection of a SGR-like burst from the AXP 4U 0142+61
  66. Swift triggers 458268 and 458269 are not astrophysical
  67. GRB 110726A: Further Swift/UVOT Observations
  68. GRB 110726A: Swift-BAT refined analysis
  69. GRB 110726A: Enhanced Swift-XRT position
  70. GRB 110726A: Swift/UVOT Detection
  71. GRB 110726A: Liverpool Telescope observations
  72. GRB 110726: ROTSE-III Detection of Optical Counterpart
  73. GRB 110726A: Swift detection of a burst
  74. GRB 110721A: Preliminary Swift/UVOT Upper Limits
  75. GRB 110721A: potential counterpart candidate
  76. GRB 110721A: Fermi-LAT detection
  77. Recent GCN/Swift-BAT Slew Burst Position notices are due to playback debugging
  78. GRB110715A: spectral lag analysis
  79. GRB 110715A : Suzaku WAM observation of the prompt emission
  80. GRB 110719A: GRT Optical Observation
  81. GRB 110719A: optical limit by "Pi of the Sky"
  82. Swift/UVOT observations of GRB110719A
  83. Swift J1822.3-1606 : Fermi GBM observation
  84. GRB 110719A: Swift-XRT refined Analysis
  85. GRB 110719A: Enhanced Swift-XRT position
  86. GRB 110719A: Swift-BAT refined analysis
  87. GRB 110719A: Swift detection of a burst
  88. GRB 110709B : Suzaku WAM observation of the prompt emission
  89. Swift J1822.3-1606: Transient Magnetar or Be X-ray Binary?
  90. GRB110715A: GROND Detection of the Optical/NIR Afterglow
  91. Swift J1822.3-1606
  92. Konus-Wind observation of GRB 110715A
  93. GRB 110715A: Swift-XRT refined Analysis
  94. Swift J1822.3-1606: Swift-XRT detection of the X-ray counterpart
  95. GRB 110715A: Swift/UVOT Detection
  96. GRB 110715A: Enhanced Swift-XRT position
  97. GRB 110715A: Swift-BAT refined analysis
  98. Swift J1822.3-1606: A Probable New SGR in Ground Analysis of BAT Data
  99. GRB 110715A: Swift detection of a bright burst with an optical counterpart
  100. GRB 110709B: Swift/UVOT Observations

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