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"

18476 results found.

  1. GRB050827: Swift-BAT detection of a burst
  2. GRB 050826: Optical Candidate
  3. GRB050824, HETE-2 Observation
  4. GRB 050826: Swift XRT preliminary analysis results
  5. GRB 050826: BAT refined analysis
  6. GRB050826: Swift/UVOT early upper limits
  7. GRB050824: First 2 hours of power low optical decay?
  8. GRB 050826: Swift XRT position
  9. GRB050826: Swift-BAT detection of a long burst
  10. GRB050824: MASTER final analysis of the OT observations
  11. Possible GRB050825:MASTER optical observations
  12. Swift-BAT trigger 152038 is definitely not a GRB
  13. GRB050824: CORRECTION to UVOT observing times
  14. Swift-BAT trigger 152038 is probably not a GRB
  15. GRB050824: Swift/UVOT detection of fading afterglow
  16. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  17. GRB050824, I-band imaging
  18. GRB 050822: refined XRT analysis
  19. GRB 050824: XRT refined analysis and possible afterglow detection
  20. GRB 050824: BAT refined analysis of a soft weak burst
  21. GRB050824: MASTER:OT decay
  22. GRB050824: MASTER observation OT
  23. GRB050805a: MASTER optical candidat
  24. GRB 050824: ROTSE-III Optical Limits
  25. GRB050824: Swift-BAT detection of a burst
  26. GRB050822: Swift/UVOT upper limits
  27. GRB 050820A BAT observations of second, larger episode of emission
  28. GRB 050822: Swift-BAT refined analysis
  29. GRB 050820a - corrections to GCN 3846
  30. Swift/UVOT UV Photometry of GRB 050820B
  31. GRB 050822: ROTSE-III Prompt Optical Limits
  32. GRB 050822: Swift detection of a long burst
  33. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  34. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  35. GRB050820a BVRcIc field photometry
  36. GRB050820B XMM-Newton observation
  37. GRB 050820a: NIR Observations by WIRO
  38. GRB 050820B: Swift XRT position
  39. GRB050820B: Refined analysis of the Swift-BAT burst
  40. GRB050820B: BAT-Swift detection of a bright GRB
  41. Swift/UVOT photometry of GRB050820
  42. GRB050820: refined XRT analysis
  43. GRB 050820: Early RAPTOR detections
  44. GRB 050820 Swift-BAT refined analysis
  45. GRB050819: refined XRT analysis
  46. GRB 050820: Swift detection of a GRB
  47. GRB050820: Optical afterglow from P60
  48. GRB 050819 Swift-BAT refined analysis
  49. GRB050819: Swift XRT position
  50. GRB050819: Swift-BAT detection of a weak burst
  51. Swift-BAT trigger 150993 is not a GRB
  52. Swift Trigger 150823 is HETE J1900.1-2455
  53. GRB050817: Swift-BAT Detection of a burst
  54. GRB050815: Optical afterglow detection by Swift UVOT
  55. GRB050815: XRT refined analysis
  56. GRB050815: Refined analysis of the Swift-BAT burst
  57. GRB 050815: ROTSE-III Optical Limits
  58. GRB050815: Swift XRT afterglow localization
  59. GRB050815: Swift-BAT detection of a burst
  60. GRB050814: P60 Optical Afterglow Candidate
  61. GRB 050814: XRT refined analysis
  62. GRB050814: SWIFT/UVOT observation
  63. GRB050814: Refined analysis of the Swift-BAT burst
  64. GRB 050814: Swift XRT Afterglow Localization
  65. GRB 050814: Swift detection of a burst
  66. GRB050813, SDSS pre-burst observations
  67. GRB 050813: KAIT optical limit
  68. GRB 050813: Swift-BAT refined analysis
  69. GRB050813: SWIFT/UVOT observation
  70. GRB 050813: Swift XRT afterglow localization
  71. GRB 050813: Possible Short Swift-BAT GRB
  72. GRB050813 (Swift 150139): P60 Observations
  73. Swift-BAT trigger 150131 is not a GRB
  74. GRB050805b: CrAO optical limit
  75. GRB050805a : Null detection report
  76. Swift-BAT trigger 149118 is very likely not a GRB
  77. Retraction of Swift Trigger 149131 (GRB 050805B)
  78. GRB 050805b: OHP optical limits
  79. GRB 050805b: TAROT optical limits
  80. GRB050805b: MASTER optical observations
  81. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  82. GRB050805a: MASTER optical candidat
  83. Swift-BAT trigger 149118 is probably not a GRB
  84. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  85. GRB 050803: Swift-BAT refined analysis
  86. GRB050803: MASTER further analys
  87. GRB 050803: early Swift XRT analysis results
  88. GRB 050803: TAROT optical limits
  89. GRB050803: MASTER optical observations
  90. GRB050803: Swift-BAT detection of a very long burst
  91. GCN GRB observation 050713A
  92. GRB 050802: Swift/UVOT optical and UV detections
  93. GRB050802 radio non-detection
  94. GRB 050730: OHP optical observations
  95. GRB 050802: early Swift XRT analysis results
  96. GRB 050802: Swift/UVOT observations
  97. GRB 050802: Swift-BAT refined analysis
  98. GRB 050802: XRT position
  99. GRB 050802: Swift Gamma-ray Burst
  100. GRB050801: Swift/UVOT Optical and UV detections

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