Skip to main content
Circulars over Kafka event name backfill. See news and announcements

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"

18428 results found.

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

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov