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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"

19533 results found.

  1. GRB 110918A: Swift-XRT observations
  2. Swift detection of short bursts from PSR J1647-4552
  3. GRB 110915A: Konus-Wind and Swift/BAT joint spectral analysis
  4. IPN triangulation of GRB 110918A (long duration, extremely intense)
  5. GRB 110915A: Swift/UVOT Upper Limits
  6. GRB 110915B: Swift/UVOT Upper Limits
  7. GRB 110915A: GROND Upper limits
  8. GRB 110915A, Swift-BAT refined analysis
  9. GRB 110915A: Swift-XRT refined Analysis
  10. GRB 110915B: XRT afterglow candidate
  11. GRB 110915A: 1.23m CAHA I-band observations
  12. GRB 110915A: Enhanced Swift-XRT position
  13. GRB 110915A: MASTER-Net early limit
  14. GRB 110915A: Prompt enhanced Swift-XRT position
  15. GRB 110915A: Swift detection of a burst
  16. GRB 110825A: Further Swift/XRT Observations
  17. GRB 110731A: SAO RAS and Terskol observations
  18. GRB 110906A(?): Burst detection (unconfirmed) from Swift-BAT slew data
  19. MAXI J1836-194 (originally GRB 110905A): Swift-BAT refined analysis
  20. GRB 110905A: Potential BAT trigger on MAXI J1836-194
  21. GRB 110905A: Swift detection of a burst
  22. GRB 110903A: Swift/UVOT Upper Limits
  23. GRB 110903A: Swift-XRT observations
  24. GRB 110820A: optical upper limit
  25. SGR Swift J1834.9-0846: Correction to the Swift-BAT refined spectral analysis
  26. Trigger 502024: Swift detection of KS 1741-293
  27. SGR Swift J1834.9-0846: Swift-BAT refined analysis of trigger 501752
  28. Swift detection of an SGR burst from Swift J1834.9-0846
  29. GRB 110827A, Swift-BAT refined analysis
  30. GRB 110827A: Swift detection of a burst
  31. GRB110825A: Swift target of opportunity observation
  32. IPN triangulation of GRB110825A (very intense, long-duration)
  33. Swift-BAT Trigger 501485 is noise
  34. Swift-BAT refined analysis of SFXT IGR J08408-4503 (trigger 501368)
  35. Swift J1834.9-0846: Precise X-ray Position and the Confirmation of its Spin Period
  36. IPN triangulation of GRB 110820B (very long duration, extremely intense)
  37. GRB 110820A: Swift/UVOT Upper Limits
  38. GRB 110820A: Swift-XRT refined Analysis
  39. GRB 110820A: Swift-BAT refined analysis
  40. GRB 110820A: Enhanced Swift-XRT position
  41. GRB 110820A: CrAO optical upper limit
  42. GRB 110820A: MASTER-NET observations
  43. GRB 110820A: Swift detection of a burst
  44. GRB 110818A: Fermi GBM observation
  45. GRB 110818A: Swift/UVOT Upper Limits
  46. GRB 110818A: Enhanced Swift-XRT position
  47. GRB 110818A: Swift-XRT refined Analysis
  48. GRB 110815A: Swift-XRT and UVOT refined Analysis
  49. GRB 110818A, Swift-BAT refined analysis
  50. GRB 110818A: Swift detection of a burst
  51. IPN triangulation of GRB110815A (long, intense)
  52. GRB 110801A: Konus-Wind and Swift/BAT joint spectral analysis
  53. GRB 110801A: optical observations at Mt. Terskol observatory
  54. Reprocessed enhanced Swift-XRT positions and GRB products: update
  55. SGR 1834.9-0846/ GRB 110807A, I-band observations
  56. IPN triangulation of GRB 110808B (short/hard/intense)
  57. RXTE Discovery of the Spin Period of Swift J1834.9-0846
  58. GRB 110808A: Swift/UVOT Detection
  59. Swift Trigger 458942 is probably not a burst
  60. GRB 110808A: Swift-BAT refined analysis
  61. GRB 110808A: Swift-XRT refined Analysis
  62. SGR J1834.9-0846: A Neutron Star in W41?
  63. Swift SGR 1834.9-0846: Swift-BAT refined analysis
  64. GRB 110808A: Enhanced Swift-XRT position
  65. GRB 110808A: Swift detection of a burst with optical counterpart
  66. Fermi GBM detection of a SGR-like burst
  67. GRB 110807A: Swift detection of a burst or a posible new SGR
  68. GRB 110726A: two epochs of SAO RAS optical observations
  69. Reprocessed enhanced Swift-XRT positions and GRB products
  70. IPN triangulation of GRB110802A (short/hard burst)
  71. GRB 110731A : Suzaku WAM observation of the prompt emission
  72. GRB 110726A: Swift-XRT refined Analysis
  73. GRB110731A: MOA optical observations of the steeply fading afterglow
  74. GRB 110801A: MASTER OT observations
  75. GRB 110801A: Swift-BAT refined analysis
  76. Swift/UVOT observations of GRB110801A
  77. GRB 110801A: Swift-XRT refined Analysis
  78. GRB 110801A: Enhanced Swift-XRT position
  79. GRB 110801A: ROTSE-III Detection of re-brightening from OT
  80. GRB 110801A: Swift detection of a burst with an optical counterpart
  81. GRB 110731A / EVLA upper limits
  82. GRB 110731A: Swift-XRT refined Analysis
  83. Konus-Wind observation of GRB 110731A
  84. GRB110731A: Swift/UVOT Observations
  85. GRB 110731A: Fermi GBM observation
  86. GRB 110731A: Enhanced Swift-XRT position
  87. Fermi-LAT Detection of GRB110731A
  88. GRB 110731A: Swift-BAT refined analysis
  89. GRB 110731A: FTN+FTS afterglow observations
  90. GRB 110731A: Swift detection of a burst with an optical counterpart
  91. GRB 110721A: Swift observations of afterglow candidate
  92. AXP 4U 0142+61: Swift-BAT refined analysis
  93. GRB 110726A: optical upper limit in CrAO
  94. Swift detection of a SGR-like burst from the AXP 4U 0142+61
  95. Swift triggers 458268 and 458269 are not astrophysical
  96. GRB 110726A: Further Swift/UVOT Observations
  97. GRB 110726A: Swift-BAT refined analysis
  98. GRB 110726A: Enhanced Swift-XRT position
  99. GRB 110726A: Swift/UVOT Detection
  100. GRB 110726A: Liverpool Telescope observations

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