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"

45438 results found.

  1. GRB050509b: Radio Observations
  2. GRB 050509b: PAIRITEL and WIYN Observations
  3. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  4. GRB 050509b: optical observations
  5. GRB 050509b: Swift XRT Position
  6. GRB 050509B: ROTSE-III Optical Limits
  7. Swift Detection of GRB050509b: A short duration burst
  8. GRB 050509a: Swift XRT Position
  9. Swift Detection of the Burst GRB050509
  10. Swift-BAT detection of GRB 050507
  11. GRB 050505: Keck I-band Magnitude
  12. GRB 050505: early time observations
  13. GRB 050505 - Faulkes Telescope North observations
  14. GRB 050502a: Swift XRT Upper Limit
  15. GRB 050505, simultaneous optical observation
  16. GRB050505: Infrared observations
  17. GRB 050505: Further Swift UVOT observations.
  18. GRB050505: AAVSO observations
  19. GRB050416A : 1 GHz limit from GMRT
  20. GRB 050505: Keck absorption spectrum and redshift (z=4.27)
  21. GRB 050505 UVOT
  22. GRB050505: Optical Afterglow Candidate
  23. GRB 050505: Swift XRT Position
  24. GRB050505 Swift-BAT refined analysis
  25. GRB 050502a: Optical Observations
  26. GRB 050416b:Swift XRT afterglow upper limits
  27. GRB 050416b:Swift XRT afterglow upper limits
  28. Swift-BAT detection of GRB050505
  29. GRB 050504: Swift XRT position
  30. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  31. GRB050502b: Afterglow Confirmation
  32. GRB050502: P200 Observations (Correction)
  33. GRB050502: P200 Observations
  34. GRB 050504 : R band observation at Lulin observatory
  35. Swift UVOT observation of GRB 050504
  36. GRB 050504, R band Observations
  37. GRB050504: Faulkes North optical robotic limit
  38. GRB 050502b, V band Observations
  39. GRB050504: P60 Observations
  40. GRB 050504: A long GRB detected with INTEGRAL
  41. GRB (?) 050504: IR Observations, Intriguing Source
  42. GRB 050502b, Optical observations
  43. GRB050502a: P60 Observations (Correction)
  44. GRB050502a: P60 Observations
  45. Renewal of SGR 1806-20 activity
  46. GRB 050502a: RBO Observations
  47. GRB 050502A: WSRT Radio Observations
  48. GRB050502A: Optical Observations
  49. GRB050502B Swift-BAT refined analysis
  50. GRB050502B: I band source in XRT error circle
  51. Swift UVOT refined analysis
  52. Retraction of Swift-BAT trigger 116145
  53. GRB 050502a : R band observation at Lulin observatory
  54. GRB 050502b : optical observation at Lulin observatory
  55. GRB 050502b: Swift XRT Position
  56. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  57. GRB050502B: Optical Limits from ANU 1m
  58. Swift Detection of the Bright Burst GRB050502b
  59. GRB 050502: INTEGRAL results
  60. GRB050502: ANU 1m optical Observations
  61. GRB 050502: Confirmed variability of the afterglow candidate +
  62. GRB 050502: PAIRITEL IR Observations
  63. GRB050502 - Correction on the Optical Candidate from the Liverpool
  64. GRB050502 - Optical Candidate from the Liverpool Telescope
  65. GRB 050502 - A long GRB detected with INTEGRAL
  66. GRB 050502: ROTSE-III Detection of Possible Counterpart
  67. Swift-BAT Trigger 115881 is not a real GRB
  68. Swift/BAT possible detection of a weak burst GRB050430
  69. GRB 050401: Rc observation
  70. GRB050416a: Radio Detection
  71. GRB 050422: Swift-UVOT observation
  72. GRB 050422: Swift-BAT refined analysis
  73. GRB 050422: Swift XRT Position
  74. Swift Detection of GRB 050422
  75. GRB 050421: NIR observations
  76. GRB 050416: Optical/NIR observations
  77. GRB 050421: SLOTIS observations
  78. GRB 050421: Further Analysis of IR imaging
  79. GRB050421: Radio Observations
  80. GRB050421: Radio Observations
  81. GRB 050421: Swift-UVOT observation
  82. GRB 050421: IR Observations
  83. GRB 050421: Swift-BAT refined analysis
  84. GRB 050421: ROTSE-III Optical Limits
  85. GRB 050421: NIR observations re-examination
  86. GRB050421
  87. GRB 050421: early Swift XRT analysis results
  88. GRB 050421: NIR observations
  89. GRB050421: P60 Observations
  90. GRB 050421: BOOTES-2 simultaneous optical observations
  91. GRB 050421: Optical observations at the INT
  92. Swift Detection of GRB050421
  93. GRB 050416b: Tentative Swift XRT Position
  94. GRB 050315: potential host galaxy
  95. GRB050326: analysis of the XMM-Newton observation
  96. GRB050418: Null Optical Observations
  97. GRB 050412: Chandra observations
  98. GRB050416A, optical observations
  99. GRB 050418: Swift-BAT refined analysis
  100. Swift-BAT detection of the bright and long GRB 050418

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