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. GRB061028: XRT refined analysis
  2. GRB 061028: Swift/UVOT Observations
  3. GRB 061028, Swift-BAT refined analysis
  4. GRB 061028: TAROT Calern observatory late optical observations
  5. GRB 061028: TAROT Calern observatory optical observations
  6. GRB 061028: Swift detection of a burst
  7. GRB 061027, Swift refined analysis of a possible burst
  8. GRB 061027: Swift detection of a possible burst
  9. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  10. GRB061025: Swift XRT refined analysis
  11. GRB061025: Swift/UVOT observations
  12. GRB 061019: MITSuME upper limits
  13. GRB 061025: REM observations
  14. GRB 061025: Gemini-S observations
  15. GRB061025: Swift XRT position
  16. GRB 061025: ROTSE-III Optical Limits
  17. GRB 061025: a long GRB detected by INTEGRAL
  18. Swift XRT boresight update
  19. GRB 061021, Swift-BAT Lag analysis
  20. Konus-Wind observation of GRB 061021
  21. GRB 061021 - VLT spectrum without lines
  22. GRB 061021: Swift-XRT refined analysis
  23. GRB 061021: Swift/UVOT Observation
  24. GRB 061021, Swift-BAT refined analysis
  25. GRB 061021: Swift detection of a burst
  26. GRB 061019: Super-LOTIS upper limit
  27. GRB060904b: optical observations
  28. GRB061019: optical observations
  29. GRB061019: optical observations
  30. GRB 061019: SARA upper limit
  31. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  32. GRB 060930: MARGE Optical Limits
  33. GRB 061019: Swift/UVOT upper limit
  34. GRB 061019: SMARTS afterglow confirmation
  35. GRB061019: Swift XRT refined analysis
  36. GRB 061019, Swift-BAT refined analysis
  37. GRB 061019: TAROT La Silla observatory optical observations
  38. GRB 061019: REM K-band candidate afterglow
  39. GRB061019: Swift/XRT position
  40. GRB 061019: Swift-BAT detection of a burst
  41. GRB 060825: GORT Observations
  42. GRB 061007: Second Epoch ATCA Radio Observations
  43. GRB 061007: RHESSI Spectral Fit
  44. GRB 061007: Suzaku/WAM observation of the prompt emission
  45. GRB 061006: astrometry-corrected XRT position
  46. Konus-Wind observation of GRB 061007
  47. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  48. GRB 061007: ATCA Radio Observations
  49. GRB061007: Swift UVOT followup observations
  50. GRB 061006: optical afterglow
  51. GRB 061006 : Suzaku/WAM observation of the prompt emission
  52. GRB 061007: OA fading and VLT redshift
  53. GRB 061007: Magellan Spectroscopy
  54. GRB 061007: Correction to GCN 5712
  55. GRB 061007: Swift-BAT refined analysis
  56. GRB 061007: Swift XRT refined analysis
  57. GRB 061006: Swift/UVOT optical observations
  58. Konus-Wind observation of the short hard GRB 061006
  59. GRB 061007 - FTS early brightening and power law decay
  60. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  61. GRB 061007: Swift detection of a burst with an optical counterpart
  62. GRB 061007: ROTSE-III Detection of Optical Counterpart
  63. GRB 061006: VLT observation
  64. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  65. GRB 061006: Swift-XRT Team Refined Analysis
  66. GRB061006 (Swift 232585) might be a short-hard GRB
  67. GRB 060930: near-IR afterglow candidate retraction
  68. GRB061006: Faulkes Telescope South Observations
  69. GRB 061006: Swift detection of a burst
  70. GRB 061004: Optical afterglow candidate and redshift
  71. GRB 061004: Las Campanas Optical/NIR Observations
  72. GRB061004: Swift/UVOT optical observations
  73. GRB 061004: Swift-XRT Team Refined Analysis
  74. GRB 061004, Swift BAT refined analysis
  75. GRB 061004: Nearby 2MASS Galaxy
  76. GRB 060928: Correction to GCN 5690
  77. GRB 061004: Swift detection of a burst
  78. GRB 060928: 2 pseudo-z from 2 detections spectral parameters
  79. Konus-Wind observation of GRB 060928
  80. GRB 060928: Suzaku/WAM observation of the prompt emission
  81. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  82. GRB 060928: Swift observations
  83. GRB 060928: RHESSI Spectral Fit
  84. IPN triangulation of GRB060928 (long, exceptionally bright)
  85. GRB061002: Swift UVOT followup observations
  86. GRB 060930: near-IR afterglow candidate
  87. GRB 061002: Swift-XRT Team Refined Analysis
  88. VLA observations of GRB 060926
  89. GRB061002 - SDSS Pre-Burst Observations
  90. GRB 061002, Swift-BAT refined analysis
  91. GRB061002: MASTER-VWF-Kislovodsk observations
  92. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  93. GRB 061002: Swift detection of a burst
  94. GRB 060908: Detection of a possible host
  95. GRB 060923A: Probable host galaxy in the R-band
  96. GRB 060807: Detection of a possible host galaxy
  97. GRB 060923A: VLA K-band Observations
  98. GRB060930: Faulkes Telescope South observation
  99. GRB 060930: Xinglong TNT optical observations
  100. GRB 060929: Further XRT 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