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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"

19594 results found.

  1. Fermi 425193729 / iPTF14cyb: Discovery of optical afterglow
  2. GRB 140622A: KAIT Optical Upper Limit
  3. GRB 140622A: Swift-XRT refined Analysis
  4. GRB 140622A: An unusual short event, Swift-BAT refined analysis
  5. GRB 140622A: RATIR Optical and NIR Observations
  6. GRB 140622A: GROND Upper limits
  7. GRB 140622A: Enhanced Swift-XRT position
  8. GRB 140622A: Swift detection of a short burst
  9. GRB 140620A: Swift/UVOT Detection
  10. GRB 140620A: Swift-XRT observations
  11. GRB 140619B: Swift-XRT observations
  12. GRB 140619A: Swift-BAT refined analysis
  13. GRB 140610A: TShAO optical upper limit
  14. GRB 140619B: Fermi-LAT Detection
  15. GRB 140619A: Swift/UVOT Observations
  16. GRB 140619A: Swift-XRT refined Analysis
  17. GRB 140619A: Enhanced Swift-XRT position
  18. GRB 140619A: Swift detection of a burst with a possible optical counterpart
  19. Swift trigger 601928 is V490 Cep: BAT+XRT refined analysis.
  20. Swift-BAT trigger 601928: Detection of a possible outburst from V490 Cep
  21. GRB 140606B: Swift XRT final light curve
  22. GRB 140614C: 1.23m CAHA (+EDIPO) observations
  23. GRB 140614B: MOSFIRE Ks-band nondetection
  24. GRB 140614C found in ground analysis of BAT data
  25. GRB 140614B: Swift-XRT refined Analysis
  26. GRB 140614B: Swift-BAT refined analysis
  27. GRB 140614A: Swift-BAT refined analysis
  28. GRB 140614A: X-shooter redshift
  29. GRB 140614B: Swift/UVOT Upper Limits
  30. GRB 140614B: RATIR Optical and NIR Observations
  31. GRB 140614A: Swift/UVOT Upper Limits
  32. GRB 140614A: Swift-XRT refined Analysis
  33. GRB 140614B: Enhanced Swift-XRT position
  34. GRB 140614B: Swift detection of a burst
  35. GRB 140614A: Enhanced Swift-XRT position
  36. GRB 140614A: GROND afterglow candidate
  37. GRB 140614A: Swift detection of a burst
  38. GRB 140611A: Swift-XRT observations
  39. Konus-Wind observation of GRB 140611A
  40. GRB 140610A: Swift-XRT refined Analysis
  41. GRB 140611A Detection of a source in BAT ground analysis
  42. GRB 140610A: Fermi GBM Detection
  43. IPN Triangulation of GRB 140611A (short/hard)
  44. GRB 140610A: RATIR Optical and NIR Observations
  45. GRB 140610A: Swift-BAT refined analysis
  46. GRB 140610A: MASTER optical observations
  47. GRB 140610A: Swift/UVOT Upper Limits
  48. Konus-Wind observation of GRB 140610A
  49. Swift/XRT returns to normal observing
  50. GRB 140610A: Swift-XRT observations
  51. GRB 140610A: Swift detection of a burst
  52. GRB 140606B: Swift XRT refined analysis
  53. GRB 140521A: AAO optical upper limit
  54. GRB 140606A: AAO optical upper limit
  55. GRB 140607A: Swift-BAT refined analysis
  56. GRB 140606B: Swift/UVOT Upper Limits
  57. GRB 140606B: Swift XRT position
  58. GRB 140607A: Swift detection of a burst
  59. GRB 140606A: BOOTES-2 optical upper limit
  60. GRB 140606A: Swift/UVOT Upper Limits
  61. GRB 140606A: Swift-XRT upper limits
  62. Swift XRT status update
  63. Swift Trigger 600914 is noise
  64. GRB 140606A: Swift-BAT refined analysis
  65. GRB 140606A: Swift detection of a short hard burst
  66. Swift Trigger 600914 is probably a noise fluctuation
  67. Swift XRT is off-line
  68. GRB 140523A: further Swift-XRT observations
  69. GRB 140529A BAT refined analysis
  70. GRB 140529A: Swift/UVOT Upper Limits
  71. GRB 140529A: Swift-XRT afterglow detection.
  72. GRB 140408A: Withdrawal of afterglow candidate
  73. GRB 140529A found in ground analysis of BAT slew data
  74. Swift Trigger 600114 in M31: UVOT Observations
  75. Swift trigger 600114 is not an outbursting X-ray source
  76. Swift Trigger 600114: Optical spectroscopy from GTC
  77. Swift Trigger 600114: Preliminary BAT analysis
  78. Swift Trigger 600114 in M31: Archival and Prompt UVOT Imaging
  79. Swift detection of a bright X-ray source in M31
  80. Swift detection of SFXT IGR J17544-2619
  81. GRB 140523A: NOT observation
  82. IPN Triangulation of GRB 140523A
  83. Swift trigger 599860 probably not real
  84. GRB 140523A: possible X-ray afterglow candidate from tiled Swift/XRT observations
  85. GRB 140523A Tiled Swift observations
  86. GRB 140523A: Fermi-LAT detection
  87. GRB 140521A: Fermi GBM Detection
  88. GRB 140423A: TShAO optical observations
  89. GRB 140521A: AAO optical observations
  90. GRB 140521A: Swift-BAT refined analysis
  91. GRB 140521A: AROMA-N Optical Observation
  92. GRB 140516A: further Swift-XRT analysis
  93. GRB 140521A: MASTER optical observations
  94. GRB 140521A: Swift detection of a burst
  95. GRB 140518A: T100 observations
  96. GRB 140512A: MASTER prompt and afterglow optical observations
  97. GRB 140518A, Swift-BAT refined analysis
  98. GRB 140518A: Swift-XRT refined Analysis
  99. GRB 140518A: Skynet GORT Detections of the Optical Afterglow
  100. GRB 140518A: Swift/UVOT Upper Limits

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