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 061006: Swift detection of a burst
  2. GRB 061004: Optical afterglow candidate and redshift
  3. GRB 061004: Las Campanas Optical/NIR Observations
  4. GRB061004: Swift/UVOT optical observations
  5. GRB 061004: Swift-XRT Team Refined Analysis
  6. GRB 061004, Swift BAT refined analysis
  7. GRB 061004: Nearby 2MASS Galaxy
  8. GRB 060928: Correction to GCN 5690
  9. GRB 061004: Swift detection of a burst
  10. GRB 060928: 2 pseudo-z from 2 detections spectral parameters
  11. Konus-Wind observation of GRB 060928
  12. GRB 060928: Suzaku/WAM observation of the prompt emission
  13. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  14. GRB 060928: Swift observations
  15. GRB 060928: RHESSI Spectral Fit
  16. IPN triangulation of GRB060928 (long, exceptionally bright)
  17. GRB061002: Swift UVOT followup observations
  18. GRB 060930: near-IR afterglow candidate
  19. GRB 061002: Swift-XRT Team Refined Analysis
  20. VLA observations of GRB 060926
  21. GRB061002 - SDSS Pre-Burst Observations
  22. GRB 061002, Swift-BAT refined analysis
  23. GRB061002: MASTER-VWF-Kislovodsk observations
  24. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  25. GRB 061002: Swift detection of a burst
  26. GRB 060908: Detection of a possible host
  27. GRB 060923A: Probable host galaxy in the R-band
  28. GRB 060807: Detection of a possible host galaxy
  29. GRB 060923A: VLA K-band Observations
  30. GRB060930: Faulkes Telescope South observation
  31. GRB 060930: Xinglong TNT optical observations
  32. GRB 060929: Further XRT Refined Analysis
  33. GRB 060929: Swift/UVOT Optical Observations
  34. GRB 060930: ROTSE-III Optical Limits
  35. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  36. GRB 060927 : GAO 150cm telescope optical observation
  37. GRB060929: Swift-XRT refined analysis.
  38. GRB 060929, Swift-BAT further refined analysis - late-time flare
  39. GRB 060929: TNG K-band observations
  40. GRB 060929, Swift-BAT refined analysis
  41. GRB060929: Optical limit
  42. GRB 060929: BART observation
  43. GRB 060929: MASTER-VWF-Kislovodsk observations
  44. GRB 060929: BOOTES-IR & OSN observations
  45. Liverpool Telescope observations of GRB 060929
  46. GRB 060929: Swift detection of a burst
  47. GRB060908: optical observations
  48. GRB 060729: An update on the late-time Swift observations
  49. GRB 060927: Spectroscopic redshift z=5.6
  50. IBAS Alert n.3501: not a GRB
  51. IBAS Alert n.3500: not a GRB
  52. GRB060923C: optical limit
  53. GRB060927: optical observations
  54. test of new software, grb
  55. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  56. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  57. GRB 060927: Swift/UVOT Optical Observations
  58. GRB 060927: Early color
  59. GRB 060927: Swift XRT Team refined analysis
  60. GRB 060927 optical limit
  61. GRB 060927, Swift-BAT refined analysis
  62. GRB 060927: Xinglong TNT optical observations
  63. GRB060926: improved redshift
  64. GRB 060927, optical observation
  65. GRB 060927: Possible host galaxy (star?) in the SDSS
  66. GRB 060927 : Kiso optical observation
  67. GRB060927: Faulkes Telescope South observation
  68. GRB 060926: MASTER: first minutes decay
  69. GRB060927 - SDSS Pre-Burst Observations
  70. GRB 060927: optical afterglow confirmation
  71. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  72. Swift XRT boresight
  73. GRB 060927: Swift detection of a burst
  74. GRB060926: VLT redshift
  75. GRB 060926: Swift-UVOT Detections
  76. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  77. GRB 060926: OPTIMA-Burst -- further observations
  78. GRB 060926: Swift XRT refined analysis
  79. GRB 060926, Swift-BAT refined analysis
  80. GRB 060923A: Radio Observations
  81. GRB 060926: MASTER OT alert observation
  82. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  83. GRB 060912A: Redshift of probable host galaxy
  84. GRB 060926: BOOTES-IR observations
  85. GRB 060926: Watcher observations
  86. GRB060926 OPTIMA-Burst optical observation
  87. GRB 060926: MASTER optical observation
  88. GRB 060926: Swift detection of a burst
  89. GRB 060923C, Swift-BAT refined analysis
  90. GRB 060923C: VLA Observation
  91. GRB 060923C: NIR afterglow confirmed
  92. GRB060923C: AROMA optical obsevation
  93. GRB 060923C: Gemini Observations and Afterglow Candidate
  94. GRB 060923C, optical observation
  95. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  96. GRB 060923C: VLT J-band observations
  97. GRB060923B: Swift/UVOT upper limits
  98. GRB 060923B: Swift XRT Refined Analysis
  99. GRB 060923C: Swift XRT refined analysis
  100. GRB 060923C, Swift-BAT partial refined analysis

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