Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

28082 results found.

  1. Swift XRT boresight update
  2. GRB 061021: Swift/UVOT Observation
  3. GRB 061021, Swift-BAT refined analysis
  4. GRB 061021: Swift detection of a burst
  5. GRB061019: optical observations
  6. GRB 061019: SARA upper limit
  7. GRB 061019: Swift/UVOT upper limit
  8. GRB 061019: SMARTS afterglow confirmation
  9. GRB061019: Swift XRT refined analysis
  10. GRB 061019, Swift-BAT refined analysis
  11. GRB 061019: TAROT La Silla observatory optical observations
  12. GRB 061019: REM K-band candidate afterglow
  13. GRB 061007: Second Epoch ATCA Radio Observations
  14. GRB 061007: Suzaku/WAM observation of the prompt emission
  15. GRB 061006: astrometry-corrected XRT position
  16. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  17. GRB 061007: ATCA Radio Observations
  18. GRB061007: Swift UVOT followup observations
  19. GRB 061006: optical afterglow
  20. GRB 061007: OA fading and VLT redshift
  21. GRB 061007: Correction to GCN 5712
  22. GRB 061007: Swift-BAT refined analysis
  23. GRB 061007: Swift XRT refined analysis
  24. GRB 061006: Swift/UVOT optical observations
  25. GRB 061007: Swift detection of a burst with an optical counterpart
  26. GRB 061007: ROTSE-III Detection of Optical Counterpart
  27. GRB 061006: VLT observation
  28. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  29. GRB 061006: Swift-XRT Team Refined Analysis
  30. GRB061006 (Swift 232585) might be a short-hard GRB
  31. GRB 060930: near-IR afterglow candidate retraction
  32. GRB 061004: Optical afterglow candidate and redshift
  33. GRB 061004: Swift-XRT Team Refined Analysis
  34. GRB 061004, Swift BAT refined analysis
  35. GRB 061004: Swift detection of a burst
  36. GRB 060928: Suzaku/WAM observation of the prompt emission
  37. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  38. GRB 060928: Swift observations
  39. IPN triangulation of GRB060928 (long, exceptionally bright)
  40. GRB 060930: near-IR afterglow candidate
  41. GRB 061002: Swift-XRT Team Refined Analysis
  42. VLA observations of GRB 060926
  43. GRB061002 - SDSS Pre-Burst Observations
  44. GRB 061002, Swift-BAT refined analysis
  45. GRB 060908: Detection of a possible host
  46. GRB 060807: Detection of a possible host galaxy
  47. GRB 060923A: VLA K-band Observations
  48. GRB 060930: Xinglong TNT optical observations
  49. GRB 060929: Further XRT Refined Analysis
  50. GRB 060929: Swift/UVOT Optical Observations
  51. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  52. GRB060929: Swift-XRT refined analysis.
  53. GRB 060929: TNG K-band observations
  54. GRB 060929, Swift-BAT refined analysis
  55. GRB060929: Optical limit
  56. Liverpool Telescope observations of GRB 060929
  57. GRB060908: optical observations
  58. GRB 060927: Swift/UVOT Optical Observations
  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. GRB 060927, optical observation
  64. GRB060927 - SDSS Pre-Burst Observations
  65. Swift XRT boresight
  66. GRB060926: VLT redshift
  67. GRB 060926: Swift-UVOT Detections
  68. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  69. GRB 060926, Swift-BAT refined analysis
  70. GRB 060923A: Radio Observations
  71. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  72. GRB 060926: Swift detection of a burst
  73. GRB 060923C, Swift-BAT refined analysis
  74. GRB 060923C: VLA Observation
  75. GRB 060923C: NIR afterglow confirmed
  76. GRB060923C: AROMA optical obsevation
  77. GRB 060923C, optical observation
  78. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  79. GRB 060923C: VLT J-band observations
  80. GRB 060923B: Swift XRT Refined Analysis
  81. GRB 060923A: Swift XRT refined analysis
  82. GRB 060923A: Keck and Gemini Observations
  83. GRB 060923C: Xinglong TNT optical observations
  84. GRB 060923B, Swift-BAT refined analysis
  85. GRB 060923C: Swift detection of a burst
  86. GRB 060923B: Swift detection of a burst
  87. GRB 060923, Swift-BAT refined analysis
  88. GRB 060923: UKIRT nIR observations - candidate afterglow
  89. GRB060923 - SDSS Pre-Burst Observations
  90. GRB 060923: Swift detection of a burst
  91. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  92. GRB 060919 : Faulkes South Telescope Observations
  93. GRB 060919, Swift-BAT refined analysis
  94. GRB060919: XRT refined analysis
  95. GRB 060919: TAROT optical observations
  96. GRB 060919: Swift detection of a burst
  97. GRB 060912A: VLA Observation
  98. GRB 060912A: Probable Host Galaxy
  99. GRB 060912, Swift-BAT refined analysis
  100. GRB 060912: Correction to GCN 5559

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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