Skip to main content
Due to the lapse in federal government funding, NASA is not updating this website. See the Operations FAQ for GCN impacts.
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

19189 results found.

  1. GRB050712: XRT refined analysis
  2. GRB 050709: Swift UVOT and XRT observations
  3. GRB 050712: Swift-BAT Refined Analysis
  4. GRB050712: UVOT candidate optical counterpart
  5. GRB 050712: Swift XRT afterglow position
  6. GRB 050712: Swift detection of a weak burst
  7. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  8. GRB 050626: Swift XRT observations
  9. GRB 050701
  10. GRB 050701, optical observations
  11. GRB 050701: Refined XRT analysis
  12. Swift UVOT observations of GRB 050701
  13. GRB050701: Swift-BAT Refined analysis
  14. GRB 050701: Swift XRT afterglow position
  15. Swift trigger 143708 is really GRB 050701
  16. GRB 050525A: Swift Late-Time Decay Rate
  17. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  18. GRB 050416(a): Host Galaxy Redshift Determination
  19. Swift/UVOT observations of GRB050607
  20. GRB 050607: RAPTOR-S Early Optical Limits
  21. GRB050607: KAIT optical limits
  22. GRB 050607: MDM Observations
  23. GRB050607,optical observation
  24. GRB 050607 - XRT refined data analysis
  25. GRB050607 optical limit by "Pi of the Sky"
  26. GRB050607: Swift Detection of a long GRB
  27. GRB 050603 - XRT data analysis of the first day
  28. Konus-Wind observation of GRB 050603
  29. GRB 050603: Analysis of UVOT data
  30. GRB050603: Fading Afterglow observed by Swift UVOT
  31. GRB 050603: Swift XRT Position
  32. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  33. Swift/BAT Detection of GRB050603
  34. GRB 050408: jet break in the XRT light curve
  35. GRB050528, XRT observations
  36. Correction to GCN Circ 3502 on GRB 050528
  37. Swift-BAT GRB 050528: a soft burst
  38. Update on Swift-BAT GRB 050528 (Trigger 130679)
  39. Possible GRB050528: no candidate from Liverpool Telescope
  40. Swift-BAT detection of possible GRB 050528
  41. GRB 050509b: refined XRT/Chandra afterglow position analysis
  42. GRB050525a: optical upper limits
  43. GRB 050525B: Swift-BAT observations
  44. GRB050525A,optical observation
  45. GRB050525: Super-LOTIS observations
  46. GRB 050525, spectral lag pseudo-redshift
  47. GRB050306: optical afterglow not confirmed
  48. GRB 050525A: BOOTES simultaneous optical observations
  49. GRB 050525A: Swift-BAT refined analysis
  50. Swift/UVOT UV and optical detections of GRB 050525
  51. Konus-Wind observation of GRB 050525
  52. GRB 050525: TAROT observations of the early afterglow
  53. INTEGRAL detection of GRB 050525
  54. GRB 050525: Optical observation
  55. GRB050525: ROTSE-III Refined Analysis
  56. GRB 050525 - Very Bright, Not Short
  57. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  58. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  59. XRF 050522: Swift XRT refined analysis
  60. Swift/UVOT observation of XRF 050522
  61. GRB 050509A: Further I-band imaging
  62. RBO Observations of GRB050522
  63. XRF 050522: Swift XRT observation
  64. GRB 050520: VLT/ULTRACAM observations
  65. Swift UVOT Observations of GRB 050520
  66. GRB 050520: Swift XRT refined analysis
  67. XRF050509C: Chandra Afterglow Detection
  68. XRF 050509c: Swift XRT Upper Limit
  69. RBO Observations of GRB050520
  70. GRB 050520: TAROT optical limit
  71. GRB 050520: Swift XRT position
  72. No Swift-BAT Lightcurves in real-time for next 3 weeks
  73. Swift-BAT trigger 122203 is not a real GRB
  74. GRB 050504: Swift XRT afterglow candidate has faded
  75. GRB 050509B: Subaru Optical Observations
  76. GRB050502b: Early Observation
  77. Refined Chandra analysis of GRB 050509b
  78. GRB050509b, SDSS pre-burst observations
  79. Chandra observation of GRB 050509b
  80. GRB 050509b: RAPTOR deep, early limits.
  81. GRB050509B: Optical/Infared observations
  82. GRB 050509b: Swift/UVOT follow-up measurements
  83. GRB 050509b Milagro GeV/TeV Observations
  84. GRB050509B: Optical observations at the Very Large Telescope
  85. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  86. GRB 050509a: Swift-BAT refined analysis
  87. GRB 050509B: WSRT Radio Observations
  88. GRB 050505: SARA Observations
  89. Swift UVOT Follow-up Observations of GRB 050509B
  90. GRB 050509B, Optical Observations
  91. GRB 050509B: Swift/XRT refined analysis
  92. GRB050509a: Swift UVOT observations
  93. GRB 050509b: Optical observations
  94. GRB 050509b: Possible Optical Counterpart
  95. GRB 050509A: Optical observations
  96. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  97. GRB 050509b: optical observations
  98. GRB 050509b: Swift XRT Position
  99. GRB 050509B: ROTSE-III Optical Limits
  100. Swift Detection of GRB050509b: A short duration burst

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