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').

18347 results found.

  1. Swift trigger 155764: bad XRT centroid
  2. Swift-BAT trigger 155535 is definitely not a GRB
  3. GRB050916 : Swift-XRT refined analysis
  4. GRB 050916: XRT position
  5. GRB 050915B: Swift-BAT refined analysis
  6. GRB 050915B: Swift/UVOT Upper Limits
  7. GRB050916: Swift-BAT detection of a long weak burst
  8. GRB 050915B: XRT position
  9. GRB050915B: Swift-BAT detection of a long bright burst
  10. GRB050915: Swift/UVOT upper limits
  11. GRB 050915: KAIT optical limit
  12. GRB 050915: IR Observations
  13. GRB 050915: Swift XRT refined analysis
  14. GRB 050915: Swift-BAT refined analysis
  15. GRB050915, optical observations
  16. GRB050915: XRT position
  17. GRB 050915: ROTSE-III optical limits
  18. GRB 050915: Swift detection of a GRB
  19. GRB050911: Upper limit on X-ray afterglow
  20. Swift-BAT trigger 155072 ground analysis
  21. Swift-BAT trigger 155072 is probably not a GRB
  22. GRB050914: XRT position probably due to cosmic ray
  23. Swift is in normal operation
  24. GRB050911: Swift UVOT followup observations
  25. GRB 050911, optical content of Swift/XRT error box
  26. GRB050911: Swift-XRT position
  27. GRB 050911, optical observations
  28. GRB 050911: Swift-BAT refined analysis
  29. Later Swift-BAT triggers 154632 and 154633 RETRACTION
  30. GRB050911: Swift-BAT detection of a long burst
  31. GRB050908: detection of Swift/UVOT optical counterpart
  32. RBO GRB 050908 observations
  33. WIRO observations in I of GRB 050908
  34. GRB 050906: Possible X-ray Counterpart
  35. GRB050908: Swift/UVOT Early upper limits
  36. GRB050908 : Swift-XRT refined analysis
  37. GRB 050908: Swift-BAT refined analysis
  38. GRB 050908: Optical observations
  39. Gemini Spectroscopy of GRB 050908
  40. GRB 050908 : Swift XRT position
  41. GRB 050908: KAIT observations
  42. GRB 050908: P60 Confirmation of Optical Afterglow
  43. GRB 050908: Swift detection of a burst
  44. Swift trigger 154073 is not a GRB
  45. GRB050904: CrAO optical observations
  46. GRB 050904 BAT refined analysis of complete data set
  47. GRB 050906: MARGE Optical Limits
  48. GRB 050906: Swift-BAT refined analysis
  49. GRB 050906: Swift XRT upper limit
  50. GRB050906: P60 Observations
  51. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  52. GRB 050906: Bright galaxy in BAT error box
  53. GRB 050906: Swift/BAT Detection of a possible burst
  54. GRB 050904: Swift/UVOT observations
  55. GRB 050904: early Swift XRT analysis results
  56. GRB 050904: BAT refined analysis of partial data set
  57. GRB050904: P60 Observations
  58. GRB 050904: TAROT optical limits
  59. GRB050904: Swift-BAT detection of a probable burst
  60. Swift-BAT triggers 153461-153465 are not GRBs
  61. Retraction of Swift-BAT trigger #153355
  62. GRB 050824: MDM Observations
  63. GRB 050827: Swift XRT preliminary analysis results
  64. Swift Trigger #152652 is not a GRB
  65. GRB050827: Swift/UVOT upper limits
  66. GRB 050827: Optical Limit
  67. GRB 050827: XRT possible afterglow detection
  68. GRB050827: RTT150 optical observations
  69. GRB 050827: Swift-BAT refined analysis
  70. GRB050827: Swift-BAT detection of a burst
  71. GRB 050826: Optical Candidate
  72. GRB050824, HETE-2 Observation
  73. GRB 050826: Swift XRT preliminary analysis results
  74. GRB 050826: BAT refined analysis
  75. GRB050826: Swift/UVOT early upper limits
  76. GRB050824: First 2 hours of power low optical decay?
  77. GRB 050826: Swift XRT position
  78. GRB050826: Swift-BAT detection of a long burst
  79. GRB050824: MASTER final analysis of the OT observations
  80. Possible GRB050825:MASTER optical observations
  81. Swift-BAT trigger 152038 is definitely not a GRB
  82. GRB050824: CORRECTION to UVOT observing times
  83. Swift-BAT trigger 152038 is probably not a GRB
  84. GRB050824: Swift/UVOT detection of fading afterglow
  85. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  86. GRB050824, I-band imaging
  87. GRB 050822: refined XRT analysis
  88. GRB 050824: XRT refined analysis and possible afterglow detection
  89. GRB 050824: BAT refined analysis of a soft weak burst
  90. GRB050824: MASTER:OT decay
  91. GRB050824: MASTER observation OT
  92. GRB050805a: MASTER optical candidat
  93. GRB 050824: ROTSE-III Optical Limits
  94. GRB050824: Swift-BAT detection of a burst
  95. GRB050822: Swift/UVOT upper limits
  96. GRB 050820A BAT observations of second, larger episode of emission
  97. GRB 050822: Swift-BAT refined analysis
  98. GRB 050820a - corrections to GCN 3846
  99. Swift/UVOT UV Photometry of GRB 050820B
  100. GRB 050822: ROTSE-III Prompt Optical Limits

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov