Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
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"
  1. GRB 061102, XRT refined analysis
  2. GRB 061004: Further VLT/NTT observations
  3. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
  4. GRB061102B: Super-LOTIS observations
  5. GRB 061028: Optical R passband observations
  6. GRB 061102B: Swift detection of a possible burst
  7. GRB 061102, Swift-BAT refined analysis
  8. GRB 061102: Swift detection of a burst
  9. GRB 061028: VLA Observation
  10. GRB 061004: Swift/XRT Astrometry Correction
  11. GRB 060801: Swift/XRT Astrometry Correction
  12. GRB 061028: Futher P200 Observations
  13. GRB 061028: MDM Observations
  14. GRB 061028: P200 Observations
  15. GRB 061028: SARA upper limit
  16. GRB 061028: z band imaging
  17. GRB061028: XRT refined analysis
  18. GRB 061028: Swift/UVOT Observations
  19. GRB 061028, Swift-BAT refined analysis
  20. GRB 061028: TAROT Calern observatory late optical observations
  21. GRB 061028: TAROT Calern observatory optical observations
  22. GRB 061028: Swift detection of a burst
  23. GRB 061027, Swift refined analysis of a possible burst
  24. GRB 061027: Swift detection of a possible burst
  25. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  26. GRB061025: Swift XRT refined analysis
  27. GRB061025: Swift/UVOT observations
  28. GRB 061019: MITSuME upper limits
  29. GRB 061025: REM observations
  30. GRB 061025: Gemini-S observations
  31. GRB061025: Swift XRT position
  32. GRB 061025: ROTSE-III Optical Limits
  33. GRB 061025: a long GRB detected by INTEGRAL
  34. Swift XRT boresight update
  35. GRB 061021, Swift-BAT Lag analysis
  36. Konus-Wind observation of GRB 061021
  37. GRB 061021 - VLT spectrum without lines
  38. GRB 061021: Swift-XRT refined analysis
  39. GRB 061021: Swift/UVOT Observation
  40. GRB 061021, Swift-BAT refined analysis
  41. GRB 061021: Swift detection of a burst
  42. GRB 061019: Super-LOTIS upper limit
  43. GRB060904b: optical observations
  44. GRB061019: optical observations
  45. GRB061019: optical observations
  46. GRB 061019: SARA upper limit
  47. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  48. GRB 060930: MARGE Optical Limits
  49. GRB 061019: Swift/UVOT upper limit
  50. GRB 061019: SMARTS afterglow confirmation
  51. GRB061019: Swift XRT refined analysis
  52. GRB 061019, Swift-BAT refined analysis
  53. GRB 061019: TAROT La Silla observatory optical observations
  54. GRB 061019: REM K-band candidate afterglow
  55. GRB061019: Swift/XRT position
  56. GRB 061019: Swift-BAT detection of a burst
  57. GRB 060825: GORT Observations
  58. GRB 061007: Second Epoch ATCA Radio Observations
  59. GRB 061007: RHESSI Spectral Fit
  60. GRB 061007: Suzaku/WAM observation of the prompt emission
  61. GRB 061006: astrometry-corrected XRT position
  62. Konus-Wind observation of GRB 061007
  63. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  64. GRB 061007: ATCA Radio Observations
  65. GRB061007: Swift UVOT followup observations
  66. GRB 061006: optical afterglow
  67. GRB 061006 : Suzaku/WAM observation of the prompt emission
  68. GRB 061007: OA fading and VLT redshift
  69. GRB 061007: Magellan Spectroscopy
  70. GRB 061007: Correction to GCN 5712
  71. GRB 061007: Swift-BAT refined analysis
  72. GRB 061007: Swift XRT refined analysis
  73. GRB 061006: Swift/UVOT optical observations
  74. Konus-Wind observation of the short hard GRB 061006
  75. GRB 061007 - FTS early brightening and power law decay
  76. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  77. GRB 061007: Swift detection of a burst with an optical counterpart
  78. GRB 061007: ROTSE-III Detection of Optical Counterpart
  79. GRB 061006: VLT observation
  80. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  81. GRB 061006: Swift-XRT Team Refined Analysis
  82. GRB061006 (Swift 232585) might be a short-hard GRB
  83. GRB 060930: near-IR afterglow candidate retraction
  84. GRB061006: Faulkes Telescope South Observations
  85. GRB 061006: Swift detection of a burst
  86. GRB 061004: Optical afterglow candidate and redshift
  87. GRB 061004: Las Campanas Optical/NIR Observations
  88. GRB061004: Swift/UVOT optical observations
  89. GRB 061004: Swift-XRT Team Refined Analysis
  90. GRB 061004, Swift BAT refined analysis
  91. GRB 061004: Nearby 2MASS Galaxy
  92. GRB 060928: Correction to GCN 5690
  93. GRB 061004: Swift detection of a burst
  94. GRB 060928: 2 pseudo-z from 2 detections spectral parameters
  95. Konus-Wind observation of GRB 060928
  96. GRB 060928: Suzaku/WAM observation of the prompt emission
  97. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  98. GRB 060928: Swift observations
  99. GRB 060928: RHESSI Spectral Fit
  100. IPN triangulation of GRB060928 (long, exceptionally bright)

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