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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 061007: Swift detection of a burst with an optical counterpart
  2. GRB 061007: ROTSE-III Detection of Optical Counterpart
  3. GRB 061006: VLT observation
  4. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  5. GRB 061006: Swift-XRT Team Refined Analysis
  6. GRB061006 (Swift 232585) might be a short-hard GRB
  7. GRB 060930: near-IR afterglow candidate retraction
  8. GRB061006: Faulkes Telescope South Observations
  9. GRB 061006: Swift detection of a burst
  10. GRB 061004: Optical afterglow candidate and redshift
  11. GRB 061004: Las Campanas Optical/NIR Observations
  12. GRB061004: Swift/UVOT optical observations
  13. GRB 061004: Swift-XRT Team Refined Analysis
  14. GRB 061004, Swift BAT refined analysis
  15. GRB 061004: Nearby 2MASS Galaxy
  16. GRB 060928: Correction to GCN 5690
  17. GRB 061004: Swift detection of a burst
  18. GRB 060928: 2 pseudo-z from 2 detections spectral parameters
  19. Konus-Wind observation of GRB 060928
  20. GRB 060928: Suzaku/WAM observation of the prompt emission
  21. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  22. GRB 060928: Swift observations
  23. GRB 060928: RHESSI Spectral Fit
  24. IPN triangulation of GRB060928 (long, exceptionally bright)
  25. GRB061002: Swift UVOT followup observations
  26. GRB 060930: near-IR afterglow candidate
  27. GRB 061002: Swift-XRT Team Refined Analysis
  28. VLA observations of GRB 060926
  29. GRB061002 - SDSS Pre-Burst Observations
  30. GRB 061002, Swift-BAT refined analysis
  31. GRB061002: MASTER-VWF-Kislovodsk observations
  32. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  33. GRB 061002: Swift detection of a burst
  34. GRB 060908: Detection of a possible host
  35. GRB 060923A: Probable host galaxy in the R-band
  36. GRB 060807: Detection of a possible host galaxy
  37. GRB 060923A: VLA K-band Observations
  38. GRB060930: Faulkes Telescope South observation
  39. GRB 060930: Xinglong TNT optical observations
  40. GRB 060929: Further XRT Refined Analysis
  41. GRB 060929: Swift/UVOT Optical Observations
  42. GRB 060930: ROTSE-III Optical Limits
  43. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  44. GRB 060927 : GAO 150cm telescope optical observation
  45. GRB060929: Swift-XRT refined analysis.
  46. GRB 060929, Swift-BAT further refined analysis - late-time flare
  47. GRB 060929: TNG K-band observations
  48. GRB 060929, Swift-BAT refined analysis
  49. GRB060929: Optical limit
  50. GRB 060929: BART observation
  51. GRB 060929: MASTER-VWF-Kislovodsk observations
  52. GRB 060929: BOOTES-IR & OSN observations
  53. Liverpool Telescope observations of GRB 060929
  54. GRB 060929: Swift detection of a burst
  55. GRB060908: optical observations
  56. GRB 060729: An update on the late-time Swift observations
  57. GRB 060927: Spectroscopic redshift z=5.6
  58. IBAS Alert n.3501: not a GRB
  59. IBAS Alert n.3500: not a GRB
  60. GRB060923C: optical limit
  61. GRB060927: optical observations
  62. test of new software, grb
  63. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  64. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  65. GRB 060927: Swift/UVOT Optical Observations
  66. GRB 060927: Early color
  67. GRB 060927: Swift XRT Team refined analysis
  68. GRB 060927 optical limit
  69. GRB 060927, Swift-BAT refined analysis
  70. GRB 060927: Xinglong TNT optical observations
  71. GRB060926: improved redshift
  72. GRB 060927, optical observation
  73. GRB 060927: Possible host galaxy (star?) in the SDSS
  74. GRB 060927 : Kiso optical observation
  75. GRB060927: Faulkes Telescope South observation
  76. GRB 060926: MASTER: first minutes decay
  77. GRB060927 - SDSS Pre-Burst Observations
  78. GRB 060927: optical afterglow confirmation
  79. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  80. Swift XRT boresight
  81. GRB 060927: Swift detection of a burst
  82. GRB060926: VLT redshift
  83. GRB 060926: Swift-UVOT Detections
  84. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  85. GRB 060926: OPTIMA-Burst -- further observations
  86. GRB 060926: Swift XRT refined analysis
  87. GRB 060926, Swift-BAT refined analysis
  88. GRB 060923A: Radio Observations
  89. GRB 060926: MASTER OT alert observation
  90. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  91. GRB 060912A: Redshift of probable host galaxy
  92. GRB 060926: BOOTES-IR observations
  93. GRB 060926: Watcher observations
  94. GRB060926 OPTIMA-Burst optical observation
  95. GRB 060926: MASTER optical observation
  96. GRB 060926: Swift detection of a burst
  97. GRB 060923C, Swift-BAT refined analysis
  98. GRB 060923C: VLA Observation
  99. GRB 060923C: NIR afterglow confirmed
  100. GRB060923C: AROMA optical obsevation

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