Skip to main content
Retirement of GCN Classic VOEvent Brokers. 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"
  1. GRB 091010: Swift-XRT refined analysis
  2. GRB 091010: Suzaku WAM observation of the prompt emission
  3. GRB 091010: AGILE-MCAL measurement and GRID upper limit
  4. Radio observation of GRB090927 with ATCA
  5. Radio observation of GRB090926a with ATCA
  6. Radio observation of GRB080916c with ATCA
  7. GRB 091010: Fermi GBM observation
  8. GRB 091010: Faulkes Telescope North observations
  9. GRB 090531A: Skynet/PROMPT Observations
  10. GRB 090530A: Skynet/DSO Detections
  11. GRB 091010: RXTE detection
  12. Konus-Wind observations of GRB 091010
  13. GRB 091010: Enhanced XRT position
  14. GRB 091010 optical upper limits
  15. Detection of a short GRB 090929A by RT-2 Experiment
  16. RT-2 observation of the bright GRB 090926A
  17. GRB 091010: GROND afterglow candidate
  18. GRB 091010: Swift/UVOT Upper Limits
  19. GRB 091010: Swift-XRT position
  20. SuperAGILE GRB is 091010 and not 090910
  21. GRB 090910: SuperAGILE Localization of a Long GRB
  22. GRB 090926A: Skynet/PROMPT Observations of Day 6 - 11 Fading
  23. GRB 090518: Skynet/PROMPT Observations
  24. Short-Duration GRB 090621: Skynet/Dolomiti Observations
  25. GRB 090904A: afterglow confirmation
  26. GRB 090812: Skynet/PROMPT and GORT Observations
  27. GRB 091003A: Suzaku WAM observation of the prompt emission
  28. GRB 091003: Lick observations and possible SDSS host galaxy
  29. GRB 090926B: Skynet/PROMPT Observations
  30. GRB 091003: WHT ACAM observations
  31. Konus-Wind observation of GRB 091003A
  32. GRB 090929B: Suzaku WAM observation of the prompt emission
  33. GRB 090929A: Suzaku WAM observation of the prompt emission
  34. GRB 091003: Swift-XRT confirmation of fading afterglow
  35. GRB 091003: Swift/UVOT Detection of an Optical Afterglow
  36. GRB 091003: Skynet/DSO Observations
  37. GRB 091003: UVOT-enhanced XRT position
  38. GRB 091003: Swift UVOT Detection of a Candidate UV Afterglow
  39. GRB 091003: Swift XRT analysis
  40. GRB 091003A: Fermi LAT detection
  41. GRB 090926A: Skynet/PROMPT Observations of Day 4 - 6 Fading Rate
  42. GRB 091003A: Fermi GBM detection
  43. GRB 090926A: Skynet/PROMPT Observations of Post-Peak Fading
  44. GRB 090929A: Swift/UVOT Observations
  45. GRB 090929A, Swift-BAT refined analysis
  46. GRB 090929B, Swift-BAT refined analysis
  47. Trigger 371210: Swift/BAT Triggered on IGR J17511-3057
  48. GRB 090929A: Swift-XRT non-detection
  49. Konus-Wind observation of GRB 090929A
  50. Konus-Wind observation of GRB 090929B
  51. GRB 090927: Fermi GBM observation
  52. GRB 090929B: Swift-XRT refined analysis
  53. GRB 090926A: Fermi LAT and GBM refined analysis
  54. GRB 090929B: Gemini-N upper limits
  55. GRB 090929B: Skynet/DSO Observations
  56. GRB 090929B: Swift/UVOT Observations
  57. Konus-RF observation of GRB 090929A
  58. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  59. GRB 090929A BAT location of the Fermi GBM burst
  60. Correction: GRB 090929B: Enhanced Swift-XRT position
  61. GRB 090929: Enhanced Swift-XRT position
  62. GRB 090929B: Swift detection of a burst
  63. GRB 090929A: Fermi GBM detection
  64. GRB090926A: Swift-XRT refined analysis
  65. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  66. Konus-Wind and Konus-RF observations of GRB 090926A
  67. GRB 090927: VLT redshift
  68. GRB 090926B: Fermi GBM detection
  69. GRB 090927: Zadko Telescope observations
  70. GRB 090927, Swift-BAT refined analysis of the possibly short burst
  71. Swift/UVOT observations of GRB 090927
  72. GRB 090926A: Skynet/PROMPT Continued Observations
  73. GRB 090927: Swift XRT refined analysis
  74. GRB 090926A: Suzaku WAM observation of the prompt emission
  75. GRB 090927: Enhanced Swift-XRT position
  76. GRB090926B: Swift/UVOT Upper Limits
  77. GRB090926A: Swift/UVOT observations
  78. GRB 090926B: VLT spectroscopy
  79. GRB 090927: Swift/UVOT detection of an optical afterglow
  80. GRB 090927: Swift detection of a short burst
  81. GRB 090926B: optical object in error circle
  82. GRB 090926B: MAXI GSC detection
  83. GRB 090926A: VLT/X-shooter redshift
  84. GRB 090926B: NOT optical observation
  85. GRB 090926B: Swift XRT refined analysis
  86. GRB 090926B: Swift-BAT refined analysis
  87. GRB 090926A: Swift/UVOT detection of an optical afterglow
  88. GRB 090926A: Skynet/PROMPT Discovery of the Optical Afterglow
  89. GRB090926A: UVOT-enhanced XRT position
  90. GRB 090926B: Swift detection of a burst
  91. GRB 090926: Fermi LAT detection
  92. GRB 090926: Fermi GBM detection
  93. GRB 090925: Fermi GBM detection
  94. GRB090904B : IRSF NIR upper limit
  95. GRB090922A: correction to Fermi location
  96. GRB 090922A: Fermi GBM detection
  97. Swift returns to normal operations
  98. GRB 090715B: Skynet/PROMPT Detections
  99. GRB 090726: Skynet/GORT Observations
  100. GRB 090916: Swift-XRT upper limit

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