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"

19938 results found.

  1. Konus-Wind observation of GRB 061021
  2. GRB 061021: Swift-XRT refined analysis
  3. GRB 061021: Swift/UVOT Observation
  4. GRB 061021, Swift-BAT refined analysis
  5. GRB 061021: Swift detection of a burst
  6. GRB 061019: Super-LOTIS upper limit
  7. GRB 061019: SARA upper limit
  8. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  9. GRB 061019: Swift/UVOT upper limit
  10. GRB061019: Swift XRT refined analysis
  11. GRB 061019, Swift-BAT refined analysis
  12. GRB 061019: TAROT La Silla observatory optical observations
  13. GRB061019: Swift/XRT position
  14. GRB 061019: Swift-BAT detection of a burst
  15. GRB 061006: astrometry-corrected XRT position
  16. Konus-Wind observation of GRB 061007
  17. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  18. GRB061007: Swift UVOT followup observations
  19. GRB 061007: Magellan Spectroscopy
  20. GRB 061007: Correction to GCN 5712
  21. GRB 061007: Swift-BAT refined analysis
  22. GRB 061007: Swift XRT refined analysis
  23. GRB 061006: Swift/UVOT optical observations
  24. Konus-Wind observation of the short hard GRB 061006
  25. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  26. GRB 061007: Swift detection of a burst with an optical counterpart
  27. GRB 061007: ROTSE-III Detection of Optical Counterpart
  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. GRB061006: Faulkes Telescope South Observations
  32. GRB 061006: Swift detection of a burst
  33. GRB061004: Swift/UVOT optical observations
  34. GRB 061004: Swift-XRT Team Refined Analysis
  35. GRB 061004, Swift BAT refined analysis
  36. GRB 061004: Swift detection of a burst
  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. GRB061002: Swift UVOT followup observations
  41. GRB 061002: Swift-XRT Team Refined Analysis
  42. GRB 061002, Swift-BAT refined analysis
  43. GRB061002: MASTER-VWF-Kislovodsk observations
  44. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  45. GRB 061002: Swift detection of a burst
  46. GRB 060929: Further XRT Refined Analysis
  47. GRB 060929: Swift/UVOT Optical Observations
  48. GRB060929: Swift-XRT refined analysis.
  49. GRB 060929, Swift-BAT further refined analysis - late-time flare
  50. GRB 060929, Swift-BAT refined analysis
  51. GRB 060929: BART observation
  52. GRB 060929: MASTER-VWF-Kislovodsk observations
  53. GRB 060929: BOOTES-IR & OSN observations
  54. Liverpool Telescope observations of GRB 060929
  55. GRB 060929: Swift detection of a burst
  56. GRB 060729: An update on the late-time Swift observations
  57. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  58. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  59. GRB 060927: Swift/UVOT Optical Observations
  60. GRB 060927: Swift XRT Team refined analysis
  61. GRB 060927, Swift-BAT refined analysis
  62. GRB060927: Faulkes Telescope South observation
  63. GRB060927 - SDSS Pre-Burst Observations
  64. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  65. Swift XRT boresight
  66. GRB 060927: Swift detection of a burst
  67. GRB060926: VLT redshift
  68. GRB 060926: Swift-UVOT Detections
  69. GRB 060926: Swift XRT refined analysis
  70. GRB 060926, Swift-BAT refined analysis
  71. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  72. GRB 060926: BOOTES-IR observations
  73. GRB060926 OPTIMA-Burst optical observation
  74. GRB 060926: Swift detection of a burst
  75. GRB 060923C, Swift-BAT refined analysis
  76. GRB 060923C: VLA Observation
  77. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  78. GRB060923B: Swift/UVOT upper limits
  79. GRB 060923B: Swift XRT Refined Analysis
  80. GRB 060923C: Swift XRT refined analysis
  81. GRB 060923C, Swift-BAT partial refined analysis
  82. GRB 060923A: Swift XRT refined analysis
  83. GRB 060923A: Keck and Gemini Observations
  84. GRB 060923B, Swift-BAT refined analysis
  85. GRB060923C : Faulkes Telescope South optical limits
  86. GRB060923C: Faulkes Telescope North optical observations
  87. GRB 060923C: Swift detection of a burst
  88. GRB 060923B: Swift detection of a burst
  89. GRB 060923, Swift-BAT refined analysis
  90. GRB 060923: Early Super-LOTIS Observations
  91. GRB060923: Faulkes Telescope North optical observations
  92. GRB 060923: KAIT observations
  93. GRB 060923: Swift detection of a burst
  94. Swift detection of IGR J17497-2821 (trigger 230504)
  95. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  96. GRB060919: Swift/UVOT optical observations
  97. GRB 060919, Swift-BAT refined analysis
  98. GRB060919: XRT refined analysis
  99. GRB 060919: TAROT optical observations
  100. GRB 060919: Swift detection of a burst

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