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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 060928: Confirmation of the X-ray afterglow detected by Swift
  2. GRB 061007: ATCA Radio Observations
  3. GRB061007: Swift UVOT followup observations
  4. GRB 061006: optical afterglow
  5. GRB 061006 : Suzaku/WAM observation of the prompt emission
  6. GRB 061007: OA fading and VLT redshift
  7. GRB 061007: Magellan Spectroscopy
  8. GRB 061007: Correction to GCN 5712
  9. GRB 061007: Swift-BAT refined analysis
  10. GRB 061007: Swift XRT refined analysis
  11. GRB 061006: Swift/UVOT optical observations
  12. Konus-Wind observation of the short hard GRB 061006
  13. GRB 061007 - FTS early brightening and power law decay
  14. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  15. GRB 061007: Swift detection of a burst with an optical counterpart
  16. GRB 061007: ROTSE-III Detection of Optical Counterpart
  17. GRB 061006: VLT observation
  18. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  19. GRB 061006: Swift-XRT Team Refined Analysis
  20. GRB061006 (Swift 232585) might be a short-hard GRB
  21. GRB 060930: near-IR afterglow candidate retraction
  22. GRB061006: Faulkes Telescope South Observations
  23. GRB 061006: Swift detection of a burst
  24. GRB 061004: Optical afterglow candidate and redshift
  25. GRB 061004: Las Campanas Optical/NIR Observations
  26. GRB061004: Swift/UVOT optical observations
  27. GRB 061004: Swift-XRT Team Refined Analysis
  28. GRB 061004, Swift BAT refined analysis
  29. GRB 061004: Nearby 2MASS Galaxy
  30. GRB 060928: Correction to GCN 5690
  31. GRB 061004: Swift detection of a burst
  32. GRB 060928: 2 pseudo-z from 2 detections spectral parameters
  33. Konus-Wind observation of GRB 060928
  34. GRB 060928: Suzaku/WAM observation of the prompt emission
  35. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  36. GRB 060928: Swift observations
  37. GRB 060928: RHESSI Spectral Fit
  38. IPN triangulation of GRB060928 (long, exceptionally bright)
  39. GRB061002: Swift UVOT followup observations
  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. GRB061002: MASTER-VWF-Kislovodsk observations
  46. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  47. GRB 061002: Swift detection of a burst
  48. GRB 060908: Detection of a possible host
  49. GRB 060923A: Probable host galaxy in the R-band
  50. GRB 060807: Detection of a possible host galaxy
  51. GRB 060923A: VLA K-band Observations
  52. GRB060930: Faulkes Telescope South observation
  53. GRB 060930: Xinglong TNT optical observations
  54. GRB 060929: Further XRT Refined Analysis
  55. GRB 060929: Swift/UVOT Optical Observations
  56. GRB 060930: ROTSE-III Optical Limits
  57. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  58. GRB 060927 : GAO 150cm telescope optical observation
  59. GRB060929: Swift-XRT refined analysis.
  60. GRB 060929, Swift-BAT further refined analysis - late-time flare
  61. GRB 060929: TNG K-band observations
  62. GRB 060929, Swift-BAT refined analysis
  63. GRB060929: Optical limit
  64. GRB 060929: BART observation
  65. GRB 060929: MASTER-VWF-Kislovodsk observations
  66. GRB 060929: BOOTES-IR & OSN observations
  67. Liverpool Telescope observations of GRB 060929
  68. GRB 060929: Swift detection of a burst
  69. GRB060908: optical observations
  70. GRB 060729: An update on the late-time Swift observations
  71. GRB 060927: Spectroscopic redshift z=5.6
  72. IBAS Alert n.3501: not a GRB
  73. IBAS Alert n.3500: not a GRB
  74. GRB060923C: optical limit
  75. GRB060927: optical observations
  76. test of new software, grb
  77. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  78. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  79. GRB 060927: Swift/UVOT Optical Observations
  80. GRB 060927: Early color
  81. GRB 060927: Swift XRT Team refined analysis
  82. GRB 060927 optical limit
  83. GRB 060927, Swift-BAT refined analysis
  84. GRB 060927: Xinglong TNT optical observations
  85. GRB060926: improved redshift
  86. GRB 060927, optical observation
  87. GRB 060927: Possible host galaxy (star?) in the SDSS
  88. GRB 060927 : Kiso optical observation
  89. GRB060927: Faulkes Telescope South observation
  90. GRB 060926: MASTER: first minutes decay
  91. GRB060927 - SDSS Pre-Burst Observations
  92. GRB 060927: optical afterglow confirmation
  93. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  94. Swift XRT boresight
  95. GRB 060927: Swift detection of a burst
  96. GRB060926: VLT redshift
  97. GRB 060926: Swift-UVOT Detections
  98. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  99. GRB 060926: OPTIMA-Burst -- further observations
  100. GRB 060926: Swift XRT refined analysis

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