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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"

35958 results found.

  1. GRB 060901: Swift/XRT Position
  2. GRB 060901: further INTEGRAL results
  3. GRB 060901: Watcher observations
  4. GRB 060901: a long GRB detected by INTEGRAL
  5. GRB 060605, observations using an Integral Field Unit
  6. GRB 060604: VLA Observation
  7. GRB 060814: Suzaku/WAM observation of the prompt emission
  8. GRB 060605: VLA Observation
  9. GRB 060707: VLA observation
  10. GRB 060825: VLA observations
  11. GRB 060825: pseudo-z from spectral parameters of the prompt emission
  12. Swift-BAT trigger 226614 is not a GRB
  13. GRB060826 - SDSS Pre-Burst Observations
  14. GRB 060826(?): Swift detection of a possible burst
  15. GRB 060825: XRT Team Refined Analysis
  16. GRB 060825: Swift-BAT Refined Analysis
  17. GRB 060813: Swift/BAT, Konus-Wind, and Suzaku/WAM joint prompt spectral analysis
  18. GRB060825: Liverpool Telescope optical observations
  19. GRB 060825: TNG optical observations
  20. GRB 060825: TAROT optical observations
  21. GRB 060825: P60 Observations
  22. GRB060825: BOOTES-IR optical observations
  23. GRB 060825: Swift detection of a burst
  24. GRB060801: host galaxy redshift
  25. GRB060729: analysis of XMM-Newton observation
  26. GRB 060814: pseudo-z from spectral parameters of the prompt
  27. Radio observations of GRB 060719
  28. GRB 060729, SMARTS optical/IR observations
  29. GRB060814: Break in the XRT light curve
  30. GRB060813: Break in the XRT light curve
  31. GRB 060813: A long, bright GRB detected with Suzaku WAM
  32. GRB 060814: Confirmation of IR afterglow
  33. Konus-Wind observation of GRB 060814
  34. GRB 060814: Refined analysis of the Swift-BAT burst
  35. GRB 060814: P60 Observations
  36. GRB 060814: P200 NIR Observations
  37. GRB 060814: source inside revised XRT error box
  38. GRB 060814: Possible IR counterpart
  39. GRB060805B: optical observations
  40. GRB060814: Swift/UVOT upper limits
  41. GRB 060813: pseudo-z from spectral parameters of the prompt
  42. GRB 060814: Swift XRT refined analysis
  43. GRB 060814: VLT optical limits
  44. GRB 060814 - SDSS Pre-Burst Observations
  45. GRB 060814: TAROT optical observations
  46. GRB 060814: Swift detection of a bright burst
  47. Konus-Wind observation of GRB 060813
  48. GRB060813: Swift/UVOT upper limits
  49. GRB 060813: Swift XRT refined analysis
  50. GRB 060813: Refined analysis of the Swift-BAT burst
  51. GRB 060813: Swift detection of a burst
  52. GRB051109B: Late-time Radio Observations
  53. Second VLA limit on new radio point source in SGR 1806-20
  54. GRB 060805B: pseudo-z from spectral parameters of the prompt emission
  55. GRB060714: optical observations
  56. IBAS Alert n. 3422: not a GRB
  57. GRB 060729: An update on the Swift XRT and UVOT observations
  58. GRB060717: optical observations
  59. GRB060807: Optical limiting magnitudes
  60. GRB 060805B: optical observation at Sierra Nevada
  61. GRB 060805B: XRT Team Analysis
  62. VLA Upper Limit on Outburst of SGR 1806-20
  63. GRB 060807: UVOT Upper limits
  64. GRB 060807: afterglow confirmation
  65. GRB 060807: XRT Team refined analysis
  66. GRB 060807: K- and R-band observations
  67. GRB 060807: Refined analysis of the Swift-BAT burst
  68. GRB060807: optical afterglow candidate
  69. GRB 060805B: RHESSI Spectral Fit
  70. GRB060807: optical upper limit in white light
  71. IPN triangulation of GRB060806 (long, exceptionally bright)
  72. GRB060807 - SDSS Pre-burst Observations
  73. GRB 060805B: X-ray Afterglow Detection, Spectral/Spatial/Temporal Properties
  74. GRB 060805B: Swift/UVOT Upper Limits
  75. GRB 060807, optical observation
  76. GRB 060807: Kanazawa R-band observation
  77. GRB 060807: optical limit
  78. GRB 060807: Swift detection of a burst
  79. GRB 060801: Second Epoch WSRT Radio Observations
  80. IPN triangulation of GRB060805B
  81. GRB 060805: optical upper limit in R
  82. GRB 060805: XRT Team Refined Analysis
  83. GRB 060805: Swift-BAT Refined Analysis
  84. GRB 060805: Swift/UVOT Upper Limits
  85. GRB 060805: P60 Observations
  86. GRB 060805: KAIT observations
  87. GRB 060805 - SDSS Pre-Burst Observations
  88. GRB 060805: Swift detection of a burst
  89. GRB 060804: Swift UVOT observations
  90. GRB 060804: Swift-XRT Team Refined Analysis
  91. GRB 060804: Refined analysis of the Swift-BAT burst
  92. GRB 060804: Swift detection of a burst with a possible UVOT counterpart
  93. GRB 060728: Upper limits of the X-ray emission
  94. GRB 060801: no variability of optical sources
  95. IBAS Alert 3418: not a GRB
  96. GRB 060801: WSRT Radio Observations
  97. GRB 060801: XRT/SDSS Frame Offset and Refined XRT Position
  98. GRB060801: Radio Observations
  99. GRB 051109B: Bright spiral host galaxy at low redshift
  100. GRB 060801: optical observations at FORS2/VLT

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