Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"

18639 results found.

  1. GRB050916: Swift-BAT detection of a long weak burst
  2. GRB 050915B: XRT position
  3. GRB050915B: Swift-BAT detection of a long bright burst
  4. GRB050915: Swift/UVOT upper limits
  5. GRB 050915: KAIT optical limit
  6. GRB 050915: IR Observations
  7. GRB 050915: Swift XRT refined analysis
  8. GRB 050915: Swift-BAT refined analysis
  9. GRB050915, optical observations
  10. GRB050915: XRT position
  11. GRB 050915: ROTSE-III optical limits
  12. GRB 050915: Swift detection of a GRB
  13. GRB050911: Upper limit on X-ray afterglow
  14. Swift-BAT trigger 155072 ground analysis
  15. Swift-BAT trigger 155072 is probably not a GRB
  16. GRB050914: XRT position probably due to cosmic ray
  17. Swift is in normal operation
  18. GRB050911: Swift UVOT followup observations
  19. GRB 050911, optical content of Swift/XRT error box
  20. GRB050911: Swift-XRT position
  21. GRB 050911, optical observations
  22. GRB 050911: Swift-BAT refined analysis
  23. Later Swift-BAT triggers 154632 and 154633 RETRACTION
  24. GRB050911: Swift-BAT detection of a long burst
  25. GRB050908: detection of Swift/UVOT optical counterpart
  26. RBO GRB 050908 observations
  27. WIRO observations in I of GRB 050908
  28. GRB 050906: Possible X-ray Counterpart
  29. GRB050908: Swift/UVOT Early upper limits
  30. GRB050908 : Swift-XRT refined analysis
  31. GRB 050908: Swift-BAT refined analysis
  32. GRB 050908: Optical observations
  33. Gemini Spectroscopy of GRB 050908
  34. GRB 050908 : Swift XRT position
  35. GRB 050908: KAIT observations
  36. GRB 050908: P60 Confirmation of Optical Afterglow
  37. GRB 050908: Swift detection of a burst
  38. Swift trigger 154073 is not a GRB
  39. GRB050904: CrAO optical observations
  40. GRB 050904 BAT refined analysis of complete data set
  41. GRB 050906: MARGE Optical Limits
  42. GRB 050906: Swift-BAT refined analysis
  43. GRB 050906: Swift XRT upper limit
  44. GRB050906: P60 Observations
  45. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  46. GRB 050906: Bright galaxy in BAT error box
  47. GRB 050906: Swift/BAT Detection of a possible burst
  48. GRB 050904: Swift/UVOT observations
  49. GRB 050904: early Swift XRT analysis results
  50. GRB 050904: BAT refined analysis of partial data set
  51. GRB050904: P60 Observations
  52. GRB 050904: TAROT optical limits
  53. GRB050904: Swift-BAT detection of a probable burst
  54. Swift-BAT triggers 153461-153465 are not GRBs
  55. Retraction of Swift-BAT trigger #153355
  56. GRB 050824: MDM Observations
  57. GRB 050827: Swift XRT preliminary analysis results
  58. Swift Trigger #152652 is not a GRB
  59. GRB050827: Swift/UVOT upper limits
  60. GRB 050827: Optical Limit
  61. GRB 050827: XRT possible afterglow detection
  62. GRB050827: RTT150 optical observations
  63. GRB 050827: Swift-BAT refined analysis
  64. GRB050827: Swift-BAT detection of a burst
  65. GRB 050826: Optical Candidate
  66. GRB050824, HETE-2 Observation
  67. GRB 050826: Swift XRT preliminary analysis results
  68. GRB 050826: BAT refined analysis
  69. GRB050826: Swift/UVOT early upper limits
  70. GRB050824: First 2 hours of power low optical decay?
  71. GRB 050826: Swift XRT position
  72. GRB050826: Swift-BAT detection of a long burst
  73. GRB050824: MASTER final analysis of the OT observations
  74. Possible GRB050825:MASTER optical observations
  75. Swift-BAT trigger 152038 is definitely not a GRB
  76. GRB050824: CORRECTION to UVOT observing times
  77. Swift-BAT trigger 152038 is probably not a GRB
  78. GRB050824: Swift/UVOT detection of fading afterglow
  79. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  80. GRB050824, I-band imaging
  81. GRB 050822: refined XRT analysis
  82. GRB 050824: XRT refined analysis and possible afterglow detection
  83. GRB 050824: BAT refined analysis of a soft weak burst
  84. GRB050824: MASTER:OT decay
  85. GRB050824: MASTER observation OT
  86. GRB050805a: MASTER optical candidat
  87. GRB 050824: ROTSE-III Optical Limits
  88. GRB050824: Swift-BAT detection of a burst
  89. GRB050822: Swift/UVOT upper limits
  90. GRB 050820A BAT observations of second, larger episode of emission
  91. GRB 050822: Swift-BAT refined analysis
  92. GRB 050820a - corrections to GCN 3846
  93. Swift/UVOT UV Photometry of GRB 050820B
  94. GRB 050822: ROTSE-III Prompt Optical Limits
  95. GRB 050822: Swift detection of a long burst
  96. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  97. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  98. GRB050820a BVRcIc field photometry
  99. GRB050820B XMM-Newton observation
  100. GRB 050820a: NIR Observations by WIRO

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