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"

28058 results found.

  1. Swift UVOT refined analysis
  2. GRB 050502a : R band observation at Lulin observatory
  3. GRB 050502b : optical observation at Lulin observatory
  4. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  5. Swift Detection of the Bright Burst GRB050502b
  6. GRB 050502: INTEGRAL results
  7. GRB 050502: ROTSE-III Detection of Possible Counterpart
  8. Swift/BAT possible detection of a weak burst GRB050430
  9. GRB050416a: Radio Detection
  10. GRB 050422: Swift-UVOT observation
  11. GRB 050422: Swift-BAT refined analysis
  12. Swift Detection of GRB 050422
  13. GRB 050421: SLOTIS observations
  14. GRB 050421: Further Analysis of IR imaging
  15. GRB050421: Radio Observations
  16. GRB050421: Radio Observations
  17. GRB 050421: IR Observations
  18. GRB 050421: Swift-BAT refined analysis
  19. GRB050421
  20. GRB 050421: early Swift XRT analysis results
  21. GRB 050421: NIR observations
  22. GRB050421: P60 Observations
  23. GRB 050421: BOOTES-2 simultaneous optical observations
  24. GRB 050416b: Tentative Swift XRT Position
  25. GRB 050315: potential host galaxy
  26. GRB050326: analysis of the XMM-Newton observation
  27. GRB050418: Null Optical Observations
  28. GRB050416A, optical observations
  29. GRB 050418: Swift-BAT refined analysis
  30. GRB 050416: Mitsume optical observation
  31. GRB050416B: IR observations
  32. GRB050412: Radio Observations
  33. GRB 050416: Swift/UVOT detection of afterglow emission
  34. GRB050416: Refined Swift-XRT analysis
  35. GRB 050416,optical observation
  36. GRB050416: P200 NIR Observations
  37. GRB 050416: Radio observations
  38. Swift BAT/XRT Detection of GRB 050416
  39. GRB 050412: PROMPT VRcIc Observations
  40. GRB 050408: Kuiper 1.5m observations
  41. GRB 050412: early Swift XRT analysis results
  42. GRB 050412: Early Optical/Ultraviolet Observations with
  43. GRB 050408: SDSS Field Calibration
  44. GRB050412: P60 Observations
  45. GRB 050412: Swift XRT Position
  46. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  47. GRB 050412: IR and Optical observations
  48. GRB 050412: IR Observations
  49. GRB050408: Radio Observations
  50. GRB 050401: Optical limit
  51. GRB050410: P60 Observations
  52. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  53. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  54. GRB050410: Radio Observations
  55. GRB050410: MASTER optical observations
  56. GRB 050410: Early observations with Swift-UVOT
  57. Swift-BAT detection of GRB 050410
  58. GRB 050408: Inconsistency of host galaxy identification
  59. GRB 050408: Subaru Observations
  60. GRB 050408: WIDGET simultaneous optical observations
  61. GRB 050408: Properties of the Host Galaxy
  62. GRB050408: Radio Observations
  63. GRB 050408: Swift XRT analysis
  64. GRB 050408: Optical limit at 20 min after the burst
  65. GRB050408: REM NIR and Optical observation
  66. GRB 050408,optical observation
  67. GRB 050408: Mercator Optical Observations
  68. GRB 050408: Optical afterglow confirmed
  69. GRB 050408: opitcal observation
  70. GRB 050408, optical observations
  71. GRB 050408 optical candidate
  72. GRB 050408: Swift XRT Position
  73. GRB050408: MASTER optical observations
  74. GRB050401: Radio Detection
  75. GRB 050406: early Swift XRT analysis results
  76. GRB 050406 BAT refined analysis
  77. GRB 050406: Early observations with Swift-UVOT
  78. Swift-BAT detection of GRB 050406
  79. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  80. GRB 050401: VLT spectroscopic redshift
  81. GRB 050401 BAT refined analysis
  82. GRB050401: TNG R-band observation
  83. GRB 050402: Early observations with Swift-UVOT
  84. Swift Trigger 113225: P60 Observations
  85. GRB 050401: Optical afterglow confirmed
  86. GRB 050401: Prompt XRT position
  87. Retraction of three Swift GRB triggers
  88. GRB050331: No Afterglow Detected
  89. Swift-BAT detection of GRB 050331b
  90. GRB 050331: Swift UVOT Source
  91. Swift-BAT detection of GRB 050331
  92. GRB 050326: Early observations with Swift-UVOT
  93. GRB 050326 XMM-Newton observation
  94. GRB 050326: Swift XRT Position
  95. GRB 050326 BAT refined analysis
  96. GRB050326: delayed XRT observation
  97. GRB050319, color indices
  98. GRB050319: optical observation, March 20-22
  99. GRB050319: RTT150 Optical Observations
  100. Swift-BAT trigger 112060 is not a real GRB

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