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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 061019: SMARTS afterglow confirmation
  2. GRB061019: Swift XRT refined analysis
  3. GRB 061019, Swift-BAT refined analysis
  4. GRB 061019: TAROT La Silla observatory optical observations
  5. GRB 061019: REM K-band candidate afterglow
  6. GRB061019: Swift/XRT position
  7. GRB 061019: Swift-BAT detection of a burst
  8. GRB 060825: GORT Observations
  9. GRB 061007: Second Epoch ATCA Radio Observations
  10. GRB 061007: RHESSI Spectral Fit
  11. GRB 061007: Suzaku/WAM observation of the prompt emission
  12. GRB 061006: astrometry-corrected XRT position
  13. Konus-Wind observation of GRB 061007
  14. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  15. GRB 061007: ATCA Radio Observations
  16. GRB061007: Swift UVOT followup observations
  17. GRB 061006: optical afterglow
  18. GRB 061006 : Suzaku/WAM observation of the prompt emission
  19. GRB 061007: OA fading and VLT redshift
  20. GRB 061007: Magellan Spectroscopy
  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. Konus-Wind observation of the short hard GRB 061006
  26. GRB 061007 - FTS early brightening and power law decay
  27. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  28. GRB 061007: Swift detection of a burst with an optical counterpart
  29. GRB 061007: ROTSE-III Detection of Optical Counterpart
  30. GRB 061006: VLT observation
  31. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  32. GRB 061006: Swift-XRT Team Refined Analysis
  33. GRB061006 (Swift 232585) might be a short-hard GRB
  34. GRB 060930: near-IR afterglow candidate retraction
  35. GRB061006: Faulkes Telescope South Observations
  36. GRB 061006: Swift detection of a burst
  37. GRB 061004: Optical afterglow candidate and redshift
  38. GRB 061004: Las Campanas Optical/NIR Observations
  39. GRB061004: Swift/UVOT optical observations
  40. GRB 061004: Swift-XRT Team Refined Analysis
  41. GRB 061004, Swift BAT refined analysis
  42. GRB 061004: Nearby 2MASS Galaxy
  43. GRB 060928: Correction to GCN 5690
  44. GRB 061004: Swift detection of a burst
  45. GRB 060928: 2 pseudo-z from 2 detections spectral parameters
  46. Konus-Wind observation of GRB 060928
  47. GRB 060928: Suzaku/WAM observation of the prompt emission
  48. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  49. GRB 060928: Swift observations
  50. GRB 060928: RHESSI Spectral Fit
  51. IPN triangulation of GRB060928 (long, exceptionally bright)
  52. GRB061002: Swift UVOT followup observations
  53. GRB 060930: near-IR afterglow candidate
  54. GRB 061002: Swift-XRT Team Refined Analysis
  55. VLA observations of GRB 060926
  56. GRB061002 - SDSS Pre-Burst Observations
  57. GRB 061002, Swift-BAT refined analysis
  58. GRB061002: MASTER-VWF-Kislovodsk observations
  59. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  60. GRB 061002: Swift detection of a burst
  61. GRB 060908: Detection of a possible host
  62. GRB 060923A: Probable host galaxy in the R-band
  63. GRB 060807: Detection of a possible host galaxy
  64. GRB 060923A: VLA K-band Observations
  65. GRB060930: Faulkes Telescope South observation
  66. GRB 060930: Xinglong TNT optical observations
  67. GRB 060929: Further XRT Refined Analysis
  68. GRB 060929: Swift/UVOT Optical Observations
  69. GRB 060930: ROTSE-III Optical Limits
  70. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  71. GRB 060927 : GAO 150cm telescope optical observation
  72. GRB060929: Swift-XRT refined analysis.
  73. GRB 060929, Swift-BAT further refined analysis - late-time flare
  74. GRB 060929: TNG K-band observations
  75. GRB 060929, Swift-BAT refined analysis
  76. GRB060929: Optical limit
  77. GRB 060929: BART observation
  78. GRB 060929: MASTER-VWF-Kislovodsk observations
  79. GRB 060929: BOOTES-IR & OSN observations
  80. Liverpool Telescope observations of GRB 060929
  81. GRB 060929: Swift detection of a burst
  82. GRB060908: optical observations
  83. GRB 060729: An update on the late-time Swift observations
  84. GRB 060927: Spectroscopic redshift z=5.6
  85. IBAS Alert n.3501: not a GRB
  86. IBAS Alert n.3500: not a GRB
  87. GRB060923C: optical limit
  88. GRB060927: optical observations
  89. test of new software, grb
  90. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  91. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  92. GRB 060927: Swift/UVOT Optical Observations
  93. GRB 060927: Early color
  94. GRB 060927: Swift XRT Team refined analysis
  95. GRB 060927 optical limit
  96. GRB 060927, Swift-BAT refined analysis
  97. GRB 060927: Xinglong TNT optical observations
  98. GRB060926: improved redshift
  99. GRB 060927, optical observation
  100. GRB 060927: Possible host galaxy (star?) in the SDSS

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