Skip to main content
Circulars over Kafka event name backfill. 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').

18310 results found.

  1. GRB 050412: IR Observations
  2. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  3. GRB 050410, optical observations
  4. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  5. GRB 050410 R band Optical Observations
  6. GRB050410 : Null detection report
  7. GRB 050410, optical observations
  8. GRB050410: Radio Observations
  9. GRB 050408: Swift XRT measurement of possible jet break
  10. GRB050410: MASTER optical observations
  11. GRB 050410: Early observations with Swift-UVOT
  12. Swift-BAT detection of GRB 050410
  13. GRB 050410: Swift XRT Position
  14. GRB 050408: Properties of the Host Galaxy
  15. GRB 050408: Swift XRT analysis
  16. GRB 050408, optical observations
  17. GRB050408: REM NIR and Optical observation
  18. GRB 050408 Optical Observations
  19. GRB 050408: Optical afterglow confirmed
  20. GRB 050408, optical observations
  21. GRB 050408 optical candidate
  22. GRB 050408: Swift XRT Position
  23. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  24. GRB 050406: early Swift XRT analysis results
  25. GRB 050406 BAT refined analysis
  26. GRB 050406: Early observations with Swift-UVOT
  27. GRB 050406: Swift XRT Position
  28. Swift-BAT detection of GRB 050406
  29. Konus-Wind observation of GRB 050401
  30. GRB050401: Radio observation at 610 MHz with GMRT
  31. GRB 050401: VLT spectroscopic redshift
  32. GRB 050401 Optical Observations
  33. GRB050401: Maidanak optical observation
  34. GRB 050401 BAT refined analysis
  35. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  36. GRB 050402A: IR Observations
  37. GRB 050402: Early observations with Swift-UVOT
  38. Swift Trigger 113225: P60 Observations
  39. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  40. GRB 050401: Optical afterglow candidate
  41. Swift-BAT detection of GRB 050401
  42. GRB 050401: Prompt XRT position
  43. Retraction of three Swift GRB triggers
  44. Swift-BAT detection of GRB 050331b
  45. GRB 050331: Swift UVOT Source
  46. Swift-BAT detection of GRB 050331
  47. GRB 050331: Swift XRT Position
  48. Swift Data Publicly Available Starting April 5, 2005
  49. Konus-Wind observation of GRB 050326
  50. GRB050326: optical limit
  51. GRB 050326: Early observations with Swift-UVOT
  52. GRB 050326 XMM-Newton observation
  53. GRB 050326 : Planned XMM-Newton observation
  54. GRB 050326: Swift XRT Position
  55. GRB050326: optical limit 33min before GRB
  56. GRB 050326 BAT refined analysis
  57. GRB050326: delayed XRT observation
  58. Swift-BAT detection of a bright GRB 050326
  59. GRB050319, optical observations
  60. GRB050319, color indices
  61. GRB050319: RTT150 Optical Observations
  62. Swift-BAT detection of a bright outburst from SGR1806-20
  63. Swift-BAT trigger 112060 is not a real GRB
  64. GRB 050319: ROTSE-III Refined Analysis
  65. GRB 050318: Swift-BAT refined analysis
  66. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  67. GRB 050319 R band observations
  68. GRB 050319: Swift-UVOT detection of the afterglow
  69. GRB 050315: Variability Analysis of Swift BAT Time History
  70. GRB050319: BR optical photometry
  71. GRB 050318: SWIFT-UVOT refined analysis
  72. GRB 050319: Swift-BAT refined analysis
  73. GRB050319,optical observation
  74. Swift Detection of GRB 050319
  75. GRB 050319: Detection of Possible Optical Counterpart
  76. GRB 050318: Swift/UVOT detection of afterglow emission
  77. GRB050318: Swift XRT position
  78. Swift-BAT detection of GRB 050318
  79. GRB050223: analysis of the XMM-Newton observation
  80. GRB 050306: ROTSE-III early limits
  81. GRB 050315: Swift-BAT further refined analysis
  82. GRB050315: Swift-BAT Refined analysis
  83. Non-detection of GRB050315 in ATCA Radio Observations
  84. GRB 050315: Swift XRT Position
  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. GRB 050126: Redshift determination
  90. Swift-BAT trigger 107873: No Swift XRT counterpart
  91. GRB 050306: Confirmation of X-ray afterglow
  92. GRB 050309, Early optical limits from RAPTOR
  93. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  94. GRB 050309 : Lulin R-band observation
  95. Swift 107873: P60 Optical Observations
  96. GRB 050306: CORRECTION to date of observation
  97. GRB 050306: No Swift UVOT Optical Counterpart Detected
  98. GRB 050306: Possible X-ray Afterglow Position from the Swift
  99. Swift trigger 107518: optical observation
  100. GRB 050306,optical observation

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