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"

28860 results found.

  1. Swift UVOT refined analysis
  2. Retraction of Swift-BAT trigger 116145
  3. Swift Detection of the Bright Burst GRB050502b
  4. GRB 050502: ROTSE-III Detection of Possible Counterpart
  5. Swift-BAT Trigger 115881 is not a real GRB
  6. Swift/BAT possible detection of a weak burst GRB050430
  7. GRB 050422: Swift-UVOT observation
  8. GRB 050422: Swift-BAT refined analysis
  9. Swift Detection of GRB 050422
  10. GRB 050421: SLOTIS observations
  11. GRB 050421: Swift-UVOT observation
  12. GRB 050421: Swift-BAT refined analysis
  13. GRB 050421: ROTSE-III Optical Limits
  14. GRB050421
  15. GRB 050421: early Swift XRT analysis results
  16. Swift Detection of GRB050421
  17. GRB 050418: Swift-BAT refined analysis
  18. Swift-BAT detection of the bright and long GRB 050418
  19. GRB 050416b: Swift-BAT refined analysis
  20. GRB050416B: IR observations
  21. GRB 050416: Swift/UVOT refined analysis
  22. Swift-BAT detection of GRB 050416b
  23. GRB 050416: Swift/UVOT detection of afterglow emission
  24. GRB050416: Refined Swift-XRT analysis
  25. GRB 050416: Swift-BAT refined analysis
  26. GRB 050416: ART observations
  27. GRB 050416,optical observation
  28. GRB 050416: KAIT observations
  29. Swift BAT/XRT Detection of GRB 050416
  30. GRB 050412: optical limit
  31. GRB 050412: early Swift XRT analysis results
  32. GRB 050412: Swift-BAT refined analysis
  33. GRB 050412: Optical limit
  34. GRB 050412: Optical observations
  35. GRB050412: ROTSE-III Optical Limits
  36. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  37. GRB 050412: IR Observations
  38. GRB 050401: Optical limit
  39. GRB 050408: Optical limit
  40. GRB 050410, optical observations
  41. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  42. GRB 050410 R band Optical Observations
  43. GRB 050408: Swift XRT measurement of possible jet break
  44. GRB 050410: Early observations with Swift-UVOT
  45. Swift-BAT detection of GRB 050410
  46. GRB 050410: Swift XRT Position
  47. GRB 050408: Swift XRT analysis
  48. GRB 050408,optical observation
  49. GRB 050408: Magellan astrometry and photometry
  50. GRB 050408: ROTSE-III Optical Limits
  51. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  52. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  53. GRB 050406: early Swift XRT analysis results
  54. GRB 050406 BAT refined analysis
  55. GRB 050406: Early observations with Swift-UVOT
  56. Swift-BAT detection of GRB 050406
  57. Konus-Wind observation of GRB 050401
  58. GRB 050401 Optical Observations
  59. GRB 050401 BAT refined analysis
  60. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  61. GRB 050402: Early observations with Swift-UVOT
  62. Swift Trigger 113225: P60 Observations
  63. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  64. GRB 050401: Optical afterglow candidate
  65. Swift-BAT detection of GRB 050401
  66. Swift-BAT detection of GRB 050331b
  67. GRB 050331: Swift UVOT Source
  68. Konus-Wind observation of GRB 050326
  69. GRB050326: optical limit
  70. GRB 050326: Early observations with Swift-UVOT
  71. GRB 050326 : Planned XMM-Newton observation
  72. GRB 050326 BAT refined analysis
  73. Swift-BAT detection of a bright GRB 050326
  74. GRB050319, optical observations
  75. Swift-BAT detection of a bright outburst from SGR1806-20
  76. Swift-BAT trigger 112060 is not a real GRB
  77. GRB 050319: ROTSE-III Refined Analysis
  78. GRB 050319: Swift-UVOT detection of the afterglow
  79. GRB 050318: SWIFT-UVOT refined analysis
  80. GRB050319,optical observation
  81. GRB 050318: Swift/UVOT detection of afterglow emission
  82. RXTE Observations of GRB050318
  83. Swift-BAT detection of GRB 050318
  84. GRB 050315: Swift-BAT further refined analysis
  85. GRB 050315: Early Observations with Swift/UVOT
  86. Swift-BAT detection of GRB 050315
  87. GRB050223: No XMM-Newton OM detection of afterglow emission
  88. GRB050309: CONCAM pre-trigger and trigger coincident optical
  89. Swift-BAT trigger 107873: No Swift XRT counterpart
  90. GRB 050309, Early optical limits from RAPTOR
  91. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  92. GRB 050309 : Lulin R-band observation
  93. Swift 107873: P60 Optical Observations
  94. GRB 050306: CORRECTION to date of observation
  95. GRB 050306: No Swift UVOT Optical Counterpart Detected
  96. Swift trigger 107518: optical observation
  97. GRB 050306,optical observation
  98. Ongoing activity of SGR 1806-20 after the giant flare
  99. GRB 050219b: candidate NIR afterglow
  100. GRB050223: No Swift UVOT Detection of Afterglow Emission

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