Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

28866 results found.

  1. Swift UVOT observation of GRB 050504
  2. GRB050504: Faulkes North optical robotic limit
  3. GRB 050502b, V band Observations
  4. GRB (?) 050504: IR Observations, Intriguing Source
  5. Renewal of SGR 1806-20 activity
  6. GRB050502B Swift-BAT refined analysis
  7. Swift UVOT refined analysis
  8. Retraction of Swift-BAT trigger 116145
  9. Swift Detection of the Bright Burst GRB050502b
  10. GRB 050502: ROTSE-III Detection of Possible Counterpart
  11. Swift-BAT Trigger 115881 is not a real GRB
  12. Swift/BAT possible detection of a weak burst GRB050430
  13. GRB 050422: Swift-UVOT observation
  14. GRB 050422: Swift-BAT refined analysis
  15. Swift Detection of GRB 050422
  16. GRB 050421: SLOTIS observations
  17. GRB 050421: Swift-UVOT observation
  18. GRB 050421: Swift-BAT refined analysis
  19. GRB 050421: ROTSE-III Optical Limits
  20. GRB050421
  21. GRB 050421: early Swift XRT analysis results
  22. Swift Detection of GRB050421
  23. GRB 050418: Swift-BAT refined analysis
  24. Swift-BAT detection of the bright and long GRB 050418
  25. GRB 050416b: Swift-BAT refined analysis
  26. GRB050416B: IR observations
  27. GRB 050416: Swift/UVOT refined analysis
  28. Swift-BAT detection of GRB 050416b
  29. GRB 050416: Swift/UVOT detection of afterglow emission
  30. GRB050416: Refined Swift-XRT analysis
  31. GRB 050416: Swift-BAT refined analysis
  32. GRB 050416: ART observations
  33. GRB 050416,optical observation
  34. GRB 050416: KAIT observations
  35. Swift BAT/XRT Detection of GRB 050416
  36. GRB 050412: optical limit
  37. GRB 050412: early Swift XRT analysis results
  38. GRB 050412: Swift-BAT refined analysis
  39. GRB 050412: Optical limit
  40. GRB 050412: Optical observations
  41. GRB050412: ROTSE-III Optical Limits
  42. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  43. GRB 050412: IR Observations
  44. GRB 050401: Optical limit
  45. GRB 050408: Optical limit
  46. GRB 050410, optical observations
  47. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  48. GRB 050410 R band Optical Observations
  49. GRB 050408: Swift XRT measurement of possible jet break
  50. GRB 050410: Early observations with Swift-UVOT
  51. Swift-BAT detection of GRB 050410
  52. GRB 050410: Swift XRT Position
  53. GRB 050408: Swift XRT analysis
  54. GRB 050408,optical observation
  55. GRB 050408: Magellan astrometry and photometry
  56. GRB 050408: ROTSE-III Optical Limits
  57. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  58. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  59. GRB 050406: early Swift XRT analysis results
  60. GRB 050406 BAT refined analysis
  61. GRB 050406: Early observations with Swift-UVOT
  62. Swift-BAT detection of GRB 050406
  63. Konus-Wind observation of GRB 050401
  64. GRB 050401 Optical Observations
  65. GRB 050401 BAT refined analysis
  66. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  67. GRB 050402: Early observations with Swift-UVOT
  68. Swift Trigger 113225: P60 Observations
  69. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  70. GRB 050401: Optical afterglow candidate
  71. Swift-BAT detection of GRB 050401
  72. Swift-BAT detection of GRB 050331b
  73. GRB 050331: Swift UVOT Source
  74. Konus-Wind observation of GRB 050326
  75. GRB050326: optical limit
  76. GRB 050326: Early observations with Swift-UVOT
  77. GRB 050326 : Planned XMM-Newton observation
  78. GRB 050326 BAT refined analysis
  79. Swift-BAT detection of a bright GRB 050326
  80. GRB050319, optical observations
  81. Swift-BAT detection of a bright outburst from SGR1806-20
  82. Swift-BAT trigger 112060 is not a real GRB
  83. GRB 050319: ROTSE-III Refined Analysis
  84. GRB 050319: Swift-UVOT detection of the afterglow
  85. GRB 050318: SWIFT-UVOT refined analysis
  86. GRB050319,optical observation
  87. GRB 050318: Swift/UVOT detection of afterglow emission
  88. RXTE Observations of GRB050318
  89. Swift-BAT detection of GRB 050318
  90. GRB 050315: Swift-BAT further refined analysis
  91. GRB 050315: Early Observations with Swift/UVOT
  92. Swift-BAT detection of GRB 050315
  93. GRB050223: No XMM-Newton OM detection of afterglow emission
  94. GRB050309: CONCAM pre-trigger and trigger coincident optical
  95. Swift-BAT trigger 107873: No Swift XRT counterpart
  96. GRB 050309, Early optical limits from RAPTOR
  97. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  98. GRB 050309 : Lulin R-band observation
  99. Swift 107873: P60 Optical Observations
  100. GRB 050306: CORRECTION to date of observation

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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