Skip to main content
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"
  1. GRB 061002: Swift-XRT Team Refined Analysis
  2. VLA observations of GRB 060926
  3. GRB061002 - SDSS Pre-Burst Observations
  4. GRB 061002, Swift-BAT refined analysis
  5. GRB061002: MASTER-VWF-Kislovodsk observations
  6. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  7. GRB 061002: Swift detection of a burst
  8. GRB 060908: Detection of a possible host
  9. GRB 060923A: Probable host galaxy in the R-band
  10. GRB 060807: Detection of a possible host galaxy
  11. GRB 060923A: VLA K-band Observations
  12. GRB060930: Faulkes Telescope South observation
  13. GRB 060930: Xinglong TNT optical observations
  14. GRB 060929: Further XRT Refined Analysis
  15. GRB 060929: Swift/UVOT Optical Observations
  16. GRB 060930: ROTSE-III Optical Limits
  17. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  18. GRB 060927 : GAO 150cm telescope optical observation
  19. GRB060929: Swift-XRT refined analysis.
  20. GRB 060929, Swift-BAT further refined analysis - late-time flare
  21. GRB 060929: TNG K-band observations
  22. GRB 060929, Swift-BAT refined analysis
  23. GRB060929: Optical limit
  24. GRB 060929: BART observation
  25. GRB 060929: MASTER-VWF-Kislovodsk observations
  26. GRB 060929: BOOTES-IR & OSN observations
  27. Liverpool Telescope observations of GRB 060929
  28. GRB 060929: Swift detection of a burst
  29. GRB060908: optical observations
  30. GRB 060729: An update on the late-time Swift observations
  31. GRB 060927: Spectroscopic redshift z=5.6
  32. IBAS Alert n.3501: not a GRB
  33. IBAS Alert n.3500: not a GRB
  34. GRB060923C: optical limit
  35. GRB060927: optical observations
  36. test of new software, grb
  37. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  38. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  39. GRB 060927: Swift/UVOT Optical Observations
  40. GRB 060927: Early color
  41. GRB 060927: Swift XRT Team refined analysis
  42. GRB 060927 optical limit
  43. GRB 060927, Swift-BAT refined analysis
  44. GRB 060927: Xinglong TNT optical observations
  45. GRB060926: improved redshift
  46. GRB 060927, optical observation
  47. GRB 060927: Possible host galaxy (star?) in the SDSS
  48. GRB 060927 : Kiso optical observation
  49. GRB060927: Faulkes Telescope South observation
  50. GRB 060926: MASTER: first minutes decay
  51. GRB060927 - SDSS Pre-Burst Observations
  52. GRB 060927: optical afterglow confirmation
  53. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  54. Swift XRT boresight
  55. GRB 060927: Swift detection of a burst
  56. GRB060926: VLT redshift
  57. GRB 060926: Swift-UVOT Detections
  58. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  59. GRB 060926: OPTIMA-Burst -- further observations
  60. GRB 060926: Swift XRT refined analysis
  61. GRB 060926, Swift-BAT refined analysis
  62. GRB 060923A: Radio Observations
  63. GRB 060926: MASTER OT alert observation
  64. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  65. GRB 060912A: Redshift of probable host galaxy
  66. GRB 060926: BOOTES-IR observations
  67. GRB 060926: Watcher observations
  68. GRB060926 OPTIMA-Burst optical observation
  69. GRB 060926: MASTER optical observation
  70. GRB 060926: Swift detection of a burst
  71. GRB 060923C, Swift-BAT refined analysis
  72. GRB 060923C: VLA Observation
  73. GRB 060923C: NIR afterglow confirmed
  74. GRB060923C: AROMA optical obsevation
  75. GRB 060923C: Gemini Observations and Afterglow Candidate
  76. GRB 060923C, optical observation
  77. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  78. GRB 060923C: VLT J-band observations
  79. GRB060923B: Swift/UVOT upper limits
  80. GRB 060923B: Swift XRT Refined Analysis
  81. GRB 060923C: Swift XRT refined analysis
  82. GRB 060923C, Swift-BAT partial refined analysis
  83. GRB 060923A: Swift XRT refined analysis
  84. GRB 060923C: Keck Observations
  85. GRB 060923A: Keck and Gemini Observations
  86. GRB 060923C: Xinglong TNT optical observations
  87. GRB 060923B, Swift-BAT refined analysis
  88. GRB060923C : Faulkes Telescope South optical limits
  89. GRB060923C: Faulkes Telescope North optical observations
  90. GRB 060923C: optical observation
  91. GRB 060923C: Swift detection of a burst
  92. GRB 060923B: Swift detection of a burst
  93. GRB 060923, Swift-BAT refined analysis
  94. GRB 060923: Early Super-LOTIS Observations
  95. GRB 060923: UKIRT nIR observations - candidate afterglow
  96. GRB060923: Faulkes Telescope North optical observations
  97. GRB060923 - SDSS Pre-Burst Observations
  98. GRB 060923: KAIT observations
  99. GRB 060923: Swift detection of a burst
  100. Swift detection of IGR J17497-2821 (trigger 230504)

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