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"

18540 results found.

  1. Swift/UVOT UV and optical detections of GRB 050525
  2. Konus-Wind observation of GRB 050525
  3. GRB 050525: TAROT observations of the early afterglow
  4. INTEGRAL detection of GRB 050525
  5. GRB 050525: Optical observation
  6. GRB050525: ROTSE-III Refined Analysis
  7. GRB 050525 - Very Bright, Not Short
  8. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  9. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  10. XRF 050522: Swift XRT refined analysis
  11. Swift/UVOT observation of XRF 050522
  12. GRB 050509A: Further I-band imaging
  13. RBO Observations of GRB050522
  14. XRF 050522: Swift XRT observation
  15. GRB 050520: VLT/ULTRACAM observations
  16. Swift UVOT Observations of GRB 050520
  17. GRB 050520: Swift XRT refined analysis
  18. XRF050509C: Chandra Afterglow Detection
  19. XRF 050509c: Swift XRT Upper Limit
  20. RBO Observations of GRB050520
  21. GRB 050520: TAROT optical limit
  22. GRB 050520: Swift XRT position
  23. No Swift-BAT Lightcurves in real-time for next 3 weeks
  24. Swift-BAT trigger 122203 is not a real GRB
  25. GRB 050504: Swift XRT afterglow candidate has faded
  26. GRB 050509B: Subaru Optical Observations
  27. GRB050502b: Early Observation
  28. Refined Chandra analysis of GRB 050509b
  29. GRB050509b, SDSS pre-burst observations
  30. Chandra observation of GRB 050509b
  31. GRB 050509b: RAPTOR deep, early limits.
  32. GRB050509B: Optical/Infared observations
  33. GRB 050509b: Swift/UVOT follow-up measurements
  34. GRB 050509b Milagro GeV/TeV Observations
  35. GRB050509B: Optical observations at the Very Large Telescope
  36. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  37. GRB 050509a: Swift-BAT refined analysis
  38. GRB 050509B: WSRT Radio Observations
  39. GRB 050505: SARA Observations
  40. Swift UVOT Follow-up Observations of GRB 050509B
  41. GRB 050509B, Optical Observations
  42. GRB 050509B: Swift/XRT refined analysis
  43. GRB050509a: Swift UVOT observations
  44. GRB 050509b: Optical observations
  45. GRB 050509b: Possible Optical Counterpart
  46. GRB 050509A: Optical observations
  47. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  48. GRB 050509b: optical observations
  49. GRB 050509b: Swift XRT Position
  50. GRB 050509B: ROTSE-III Optical Limits
  51. Swift Detection of GRB050509b: A short duration burst
  52. GRB 050509a: Swift XRT Position
  53. Swift Detection of the Burst GRB050509
  54. Swift-BAT detection of GRB 050507
  55. GRB 050505: early time observations
  56. GRB 050505 - Faulkes Telescope North observations
  57. GRB 050502a: Swift XRT Upper Limit
  58. GRB 050505, simultaneous optical observation
  59. GRB 050505: Further Swift UVOT observations.
  60. GRB050416A : 1 GHz limit from GMRT
  61. GRB 050505 UVOT
  62. GRB 050505: Swift XRT Position
  63. GRB050505 Swift-BAT refined analysis
  64. GRB 050416b:Swift XRT afterglow upper limits
  65. GRB 050416b:Swift XRT afterglow upper limits
  66. Swift-BAT detection of GRB050505
  67. GRB 050504: Swift XRT position
  68. Swift UVOT observation of GRB 050504
  69. GRB 050502b, V band Observations
  70. GRB050502B Swift-BAT refined analysis
  71. GRB050502B: I band source in XRT error circle
  72. Swift UVOT refined analysis
  73. Retraction of Swift-BAT trigger 116145
  74. GRB 050502b : optical observation at Lulin observatory
  75. GRB 050502b: Swift XRT Position
  76. GRB050502B: Optical Limits from ANU 1m
  77. Swift Detection of the Bright Burst GRB050502b
  78. GRB050502: ANU 1m optical Observations
  79. Swift-BAT Trigger 115881 is not a real GRB
  80. Swift/BAT possible detection of a weak burst GRB050430
  81. GRB 050401: Rc observation
  82. GRB050416a: Radio Detection
  83. GRB 050422: Swift-UVOT observation
  84. GRB 050422: Swift-BAT refined analysis
  85. GRB 050422: Swift XRT Position
  86. Swift Detection of GRB 050422
  87. GRB 050421: SLOTIS observations
  88. GRB050421: Radio Observations
  89. GRB050421: Radio Observations
  90. GRB 050421: Swift-UVOT observation
  91. GRB 050421: Swift-BAT refined analysis
  92. GRB 050421: ROTSE-III Optical Limits
  93. GRB 050421: early Swift XRT analysis results
  94. GRB 050421: BOOTES-2 simultaneous optical observations
  95. GRB 050421: Optical observations at the INT
  96. Swift Detection of GRB050421
  97. GRB 050416b: Tentative Swift XRT Position
  98. GRB050326: analysis of the XMM-Newton observation
  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:
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