Skip to main content
Circulars over Kafka event name backfill. 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"

19223 results found.

  1. GRB061122: Swift-XRT position
  2. Konus-Wind observation of GRB 061122
  3. RHESSI Spectrum of GRB061121
  4. Konus-Wind and Konus-A observations of GRB 061121
  5. Swift-BAT trigger 239987 is not a GRB
  6. GRB 061121: Swift/UVOT Observations
  7. GRB 061121, Swift-BAT refined analysis
  8. GRB061121, optical observation
  9. GRB 061121: Optical observation at the KANATA 1.5m telescope
  10. GRB 061121: Swift detection of a bright burst with an optical counterpart
  11. GRB 060605: NIR Observations
  12. GRB 050915B: optical afterglow
  13. Swift/UVOT Upper Limits for GRB061110b
  14. Swift/UVOT Upper Limits for GRB061110a
  15. GRB 061110B, Swift-BAT refined analysis
  16. GRB061110B: Optical observations at Crni Vrh
  17. GRB 061110A, Swift-BAT refined analysis
  18. GRB 061110B: TAROT Calern observatory optical observations
  19. GRB 061110B: Swift detection of a burst
  20. GRB 061110: Candidate confirmed
  21. GRB 061110: ROTSE-III Optical Limits
  22. GRB 061110: Swift detection of a burst
  23. GRB061110A - Optical Non-detection
  24. GRB 061109: TAROT Calern observatory optical observations
  25. GRB 061027: TAROT La Silla observatory optical observations
  26. GRB 061028: Swift/XRT Astrometry Correction
  27. GRB 061102: Swift/UVOT Magnitude Upper Limits
  28. GRB061102B: Super-LOTIS observations
  29. GRB 061028: Optical R passband observations
  30. GRB 061102B: Swift detection of a possible burst
  31. GRB 061102: Swift detection of a burst
  32. GRB 061028: VLA Observation
  33. GRB 061004: Swift/XRT Astrometry Correction
  34. GRB 060801: Swift/XRT Astrometry Correction
  35. GRB 061028: Futher P200 Observations
  36. GRB 061028: P200 Observations
  37. GRB 061028: SARA upper limit
  38. GRB 061028: z band imaging
  39. GRB 061028: Swift/UVOT Observations
  40. GRB 061028, Swift-BAT refined analysis
  41. GRB 061028: TAROT Calern observatory optical observations
  42. GRB 061028: Swift detection of a burst
  43. GRB 061027, Swift refined analysis of a possible burst
  44. GRB 061027: Swift detection of a possible burst
  45. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  46. GRB061025: Swift/UVOT observations
  47. GRB 061025: REM observations
  48. GRB 061025: ROTSE-III Optical Limits
  49. Konus-Wind observation of GRB 061021
  50. GRB 061021: Swift-XRT refined analysis
  51. GRB 061021: Swift/UVOT Observation
  52. GRB 061021: Swift detection of a burst
  53. GRB060904b: optical observations
  54. GRB 061019: SARA upper limit
  55. GRB 061019: Swift/UVOT upper limit
  56. GRB 061019, Swift-BAT refined analysis
  57. GRB 061019: TAROT La Silla observatory optical observations
  58. GRB 061019: REM K-band candidate afterglow
  59. GRB 061007: Suzaku/WAM observation of the prompt emission
  60. GRB 061006: astrometry-corrected XRT position
  61. Konus-Wind observation of GRB 061007
  62. GRB061007: Swift UVOT followup observations
  63. GRB 061006: optical afterglow
  64. GRB 061006 : Suzaku/WAM observation of the prompt emission
  65. GRB 061007: OA fading and VLT redshift
  66. GRB 061007: Swift-BAT refined analysis
  67. GRB 061007: Swift XRT refined analysis
  68. GRB 061006: Swift/UVOT optical observations
  69. Konus-Wind observation of the short hard GRB 061006
  70. GRB 061007: Swift detection of a burst with an optical counterpart
  71. GRB 061006: VLT observation
  72. GRB 060930: near-IR afterglow candidate retraction
  73. GRB 061006: Swift detection of a burst
  74. GRB 061004: Optical afterglow candidate and redshift
  75. GRB 061004: Swift detection of a burst
  76. Konus-Wind observation of GRB 060928
  77. GRB 060928: Suzaku/WAM observation of the prompt emission
  78. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  79. GRB 060928: Swift observations
  80. GRB 060928: RHESSI Spectral Fit
  81. IPN triangulation of GRB060928 (long, exceptionally bright)
  82. GRB 060930: near-IR afterglow candidate
  83. VLA observations of GRB 060926
  84. GRB061002 - SDSS Pre-Burst Observations
  85. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  86. GRB 061002: Swift detection of a burst
  87. GRB 060908: Detection of a possible host
  88. GRB 060923A: Probable host galaxy in the R-band
  89. GRB 060807: Detection of a possible host galaxy
  90. GRB 060923A: VLA K-band Observations
  91. GRB 060930: Xinglong TNT optical observations
  92. GRB 060929: Swift/UVOT Optical Observations
  93. GRB 060930: ROTSE-III Optical Limits
  94. GRB 060929: TNG K-band observations
  95. GRB 060929, Swift-BAT refined analysis
  96. GRB060929: Optical limit
  97. Liverpool Telescope observations of GRB 060929
  98. GRB060908: optical observations
  99. GRB 060927: Swift/UVOT Optical Observations
  100. GRB 060927 optical limit

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov