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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: OA fading and VLT redshift
  2. GRB 061007: Magellan Spectroscopy
  3. GRB 061007: Correction to GCN 5712
  4. GRB 061007: Swift-BAT refined analysis
  5. GRB 061007: Swift XRT refined analysis
  6. GRB 061006: Swift/UVOT optical observations
  7. Konus-Wind observation of the short hard GRB 061006
  8. GRB 061007 - FTS early brightening and power law decay
  9. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  10. GRB 061007: Swift detection of a burst with an optical counterpart
  11. GRB 061007: ROTSE-III Detection of Optical Counterpart
  12. GRB 061006: VLT observation
  13. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  14. GRB 061006: Swift-XRT Team Refined Analysis
  15. GRB061006 (Swift 232585) might be a short-hard GRB
  16. GRB 060930: near-IR afterglow candidate retraction
  17. GRB061006: Faulkes Telescope South Observations
  18. GRB 061006: Swift detection of a burst
  19. GRB 061004: Optical afterglow candidate and redshift
  20. GRB 061004: Las Campanas Optical/NIR Observations
  21. GRB061004: Swift/UVOT optical observations
  22. GRB 061004: Swift-XRT Team Refined Analysis
  23. GRB 061004, Swift BAT refined analysis
  24. GRB 061004: Nearby 2MASS Galaxy
  25. GRB 060928: Correction to GCN 5690
  26. GRB 061004: Swift detection of a burst
  27. GRB 060928: 2 pseudo-z from 2 detections spectral parameters
  28. Konus-Wind observation of GRB 060928
  29. GRB 060928: Suzaku/WAM observation of the prompt emission
  30. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  31. GRB 060928: Swift observations
  32. GRB 060928: RHESSI Spectral Fit
  33. IPN triangulation of GRB060928 (long, exceptionally bright)
  34. GRB061002: Swift UVOT followup observations
  35. GRB 060930: near-IR afterglow candidate
  36. GRB 061002: Swift-XRT Team Refined Analysis
  37. VLA observations of GRB 060926
  38. GRB061002 - SDSS Pre-Burst Observations
  39. GRB 061002, Swift-BAT refined analysis
  40. GRB061002: MASTER-VWF-Kislovodsk observations
  41. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  42. GRB 061002: Swift detection of a burst
  43. GRB 060908: Detection of a possible host
  44. GRB 060923A: Probable host galaxy in the R-band
  45. GRB 060807: Detection of a possible host galaxy
  46. GRB 060923A: VLA K-band Observations
  47. GRB060930: Faulkes Telescope South observation
  48. GRB 060930: Xinglong TNT optical observations
  49. GRB 060929: Further XRT Refined Analysis
  50. GRB 060929: Swift/UVOT Optical Observations
  51. GRB 060930: ROTSE-III Optical Limits
  52. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  53. GRB 060927 : GAO 150cm telescope optical observation
  54. GRB060929: Swift-XRT refined analysis.
  55. GRB 060929, Swift-BAT further refined analysis - late-time flare
  56. GRB 060929: TNG K-band observations
  57. GRB 060929, Swift-BAT refined analysis
  58. GRB060929: Optical limit
  59. GRB 060929: BART observation
  60. GRB 060929: MASTER-VWF-Kislovodsk observations
  61. GRB 060929: BOOTES-IR & OSN observations
  62. Liverpool Telescope observations of GRB 060929
  63. GRB 060929: Swift detection of a burst
  64. GRB060908: optical observations
  65. GRB 060729: An update on the late-time Swift observations
  66. GRB 060927: Spectroscopic redshift z=5.6
  67. IBAS Alert n.3501: not a GRB
  68. IBAS Alert n.3500: not a GRB
  69. GRB060923C: optical limit
  70. GRB060927: optical observations
  71. test of new software, grb
  72. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  73. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  74. GRB 060927: Swift/UVOT Optical Observations
  75. GRB 060927: Early color
  76. GRB 060927: Swift XRT Team refined analysis
  77. GRB 060927 optical limit
  78. GRB 060927, Swift-BAT refined analysis
  79. GRB 060927: Xinglong TNT optical observations
  80. GRB060926: improved redshift
  81. GRB 060927, optical observation
  82. GRB 060927: Possible host galaxy (star?) in the SDSS
  83. GRB 060927 : Kiso optical observation
  84. GRB060927: Faulkes Telescope South observation
  85. GRB 060926: MASTER: first minutes decay
  86. GRB060927 - SDSS Pre-Burst Observations
  87. GRB 060927: optical afterglow confirmation
  88. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  89. Swift XRT boresight
  90. GRB 060927: Swift detection of a burst
  91. GRB060926: VLT redshift
  92. GRB 060926: Swift-UVOT Detections
  93. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  94. GRB 060926: OPTIMA-Burst -- further observations
  95. GRB 060926: Swift XRT refined analysis
  96. GRB 060926, Swift-BAT refined analysis
  97. GRB 060923A: Radio Observations
  98. GRB 060926: MASTER OT alert observation
  99. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  100. GRB 060912A: Redshift of probable host galaxy

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