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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. Konus-Wind observation of GRB 061021
  2. GRB 061021 - VLT spectrum without lines
  3. GRB 061021: Swift-XRT refined analysis
  4. GRB 061021: Swift/UVOT Observation
  5. GRB 061021, Swift-BAT refined analysis
  6. GRB 061021: Swift detection of a burst
  7. GRB 061019: Super-LOTIS upper limit
  8. GRB060904b: optical observations
  9. GRB061019: optical observations
  10. GRB061019: optical observations
  11. GRB 061019: SARA upper limit
  12. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  13. GRB 060930: MARGE Optical Limits
  14. GRB 061019: Swift/UVOT upper limit
  15. GRB 061019: SMARTS afterglow confirmation
  16. GRB061019: Swift XRT refined analysis
  17. GRB 061019, Swift-BAT refined analysis
  18. GRB 061019: TAROT La Silla observatory optical observations
  19. GRB 061019: REM K-band candidate afterglow
  20. GRB061019: Swift/XRT position
  21. GRB 061019: Swift-BAT detection of a burst
  22. GRB 060825: GORT Observations
  23. GRB 061007: Second Epoch ATCA Radio Observations
  24. GRB 061007: RHESSI Spectral Fit
  25. GRB 061007: Suzaku/WAM observation of the prompt emission
  26. GRB 061006: astrometry-corrected XRT position
  27. Konus-Wind observation of GRB 061007
  28. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  29. GRB 061007: ATCA Radio Observations
  30. GRB061007: Swift UVOT followup observations
  31. GRB 061006: optical afterglow
  32. GRB 061006 : Suzaku/WAM observation of the prompt emission
  33. GRB 061007: OA fading and VLT redshift
  34. GRB 061007: Magellan Spectroscopy
  35. GRB 061007: Correction to GCN 5712
  36. GRB 061007: Swift-BAT refined analysis
  37. GRB 061007: Swift XRT refined analysis
  38. GRB 061006: Swift/UVOT optical observations
  39. Konus-Wind observation of the short hard GRB 061006
  40. GRB 061007 - FTS early brightening and power law decay
  41. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  42. GRB 061007: Swift detection of a burst with an optical counterpart
  43. GRB 061007: ROTSE-III Detection of Optical Counterpart
  44. GRB 061006: VLT observation
  45. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  46. GRB 061006: Swift-XRT Team Refined Analysis
  47. GRB061006 (Swift 232585) might be a short-hard GRB
  48. GRB 060930: near-IR afterglow candidate retraction
  49. GRB061006: Faulkes Telescope South Observations
  50. GRB 061006: Swift detection of a burst
  51. GRB 061004: Optical afterglow candidate and redshift
  52. GRB 061004: Las Campanas Optical/NIR Observations
  53. GRB061004: Swift/UVOT optical observations
  54. GRB 061004: Swift-XRT Team Refined Analysis
  55. GRB 061004, Swift BAT refined analysis
  56. GRB 061004: Nearby 2MASS Galaxy
  57. GRB 060928: Correction to GCN 5690
  58. GRB 061004: Swift detection of a burst
  59. GRB 060928: 2 pseudo-z from 2 detections spectral parameters
  60. Konus-Wind observation of GRB 060928
  61. GRB 060928: Suzaku/WAM observation of the prompt emission
  62. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  63. GRB 060928: Swift observations
  64. GRB 060928: RHESSI Spectral Fit
  65. IPN triangulation of GRB060928 (long, exceptionally bright)
  66. GRB061002: Swift UVOT followup observations
  67. GRB 060930: near-IR afterglow candidate
  68. GRB 061002: Swift-XRT Team Refined Analysis
  69. VLA observations of GRB 060926
  70. GRB061002 - SDSS Pre-Burst Observations
  71. GRB 061002, Swift-BAT refined analysis
  72. GRB061002: MASTER-VWF-Kislovodsk observations
  73. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  74. GRB 061002: Swift detection of a burst
  75. GRB 060908: Detection of a possible host
  76. GRB 060923A: Probable host galaxy in the R-band
  77. GRB 060807: Detection of a possible host galaxy
  78. GRB 060923A: VLA K-band Observations
  79. GRB060930: Faulkes Telescope South observation
  80. GRB 060930: Xinglong TNT optical observations
  81. GRB 060929: Further XRT Refined Analysis
  82. GRB 060929: Swift/UVOT Optical Observations
  83. GRB 060930: ROTSE-III Optical Limits
  84. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  85. GRB 060927 : GAO 150cm telescope optical observation
  86. GRB060929: Swift-XRT refined analysis.
  87. GRB 060929, Swift-BAT further refined analysis - late-time flare
  88. GRB 060929: TNG K-band observations
  89. GRB 060929, Swift-BAT refined analysis
  90. GRB060929: Optical limit
  91. GRB 060929: BART observation
  92. GRB 060929: MASTER-VWF-Kislovodsk observations
  93. GRB 060929: BOOTES-IR & OSN observations
  94. Liverpool Telescope observations of GRB 060929
  95. GRB 060929: Swift detection of a burst
  96. GRB060908: optical observations
  97. GRB 060729: An update on the late-time Swift observations
  98. GRB 060927: Spectroscopic redshift z=5.6
  99. IBAS Alert n.3501: not a GRB
  100. IBAS Alert n.3500: not a GRB

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