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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"

35939 results found.

  1. GRB 060825: TAROT optical observations
  2. GRB 060825: P60 Observations
  3. GRB060825: BOOTES-IR optical observations
  4. GRB 060825: Swift detection of a burst
  5. GRB060801: host galaxy redshift
  6. GRB060729: analysis of XMM-Newton observation
  7. GRB 060814: pseudo-z from spectral parameters of the prompt
  8. Radio observations of GRB 060719
  9. GRB 060729, SMARTS optical/IR observations
  10. GRB060814: Break in the XRT light curve
  11. GRB060813: Break in the XRT light curve
  12. GRB 060813: A long, bright GRB detected with Suzaku WAM
  13. GRB 060814: Confirmation of IR afterglow
  14. Konus-Wind observation of GRB 060814
  15. GRB 060814: Refined analysis of the Swift-BAT burst
  16. GRB 060814: P60 Observations
  17. GRB 060814: P200 NIR Observations
  18. GRB 060814: source inside revised XRT error box
  19. GRB 060814: Possible IR counterpart
  20. GRB060805B: optical observations
  21. GRB060814: Swift/UVOT upper limits
  22. GRB 060813: pseudo-z from spectral parameters of the prompt
  23. GRB 060814: Swift XRT refined analysis
  24. GRB 060814: VLT optical limits
  25. GRB 060814 - SDSS Pre-Burst Observations
  26. GRB 060814: TAROT optical observations
  27. GRB 060814: Swift detection of a bright burst
  28. Konus-Wind observation of GRB 060813
  29. GRB060813: Swift/UVOT upper limits
  30. GRB 060813: Swift XRT refined analysis
  31. GRB 060813: Refined analysis of the Swift-BAT burst
  32. GRB 060813: Swift detection of a burst
  33. GRB051109B: Late-time Radio Observations
  34. Second VLA limit on new radio point source in SGR 1806-20
  35. GRB 060805B: pseudo-z from spectral parameters of the prompt emission
  36. GRB060714: optical observations
  37. IBAS Alert n. 3422: not a GRB
  38. GRB 060729: An update on the Swift XRT and UVOT observations
  39. GRB060717: optical observations
  40. GRB060807: Optical limiting magnitudes
  41. GRB 060805B: optical observation at Sierra Nevada
  42. GRB 060805B: XRT Team Analysis
  43. VLA Upper Limit on Outburst of SGR 1806-20
  44. GRB 060807: UVOT Upper limits
  45. GRB 060807: afterglow confirmation
  46. GRB 060807: XRT Team refined analysis
  47. GRB 060807: K- and R-band observations
  48. GRB 060807: Refined analysis of the Swift-BAT burst
  49. GRB060807: optical afterglow candidate
  50. GRB 060805B: RHESSI Spectral Fit
  51. GRB060807: optical upper limit in white light
  52. IPN triangulation of GRB060806 (long, exceptionally bright)
  53. GRB060807 - SDSS Pre-burst Observations
  54. GRB 060805B: X-ray Afterglow Detection, Spectral/Spatial/Temporal Properties
  55. GRB 060805B: Swift/UVOT Upper Limits
  56. GRB 060807, optical observation
  57. GRB 060807: Kanazawa R-band observation
  58. GRB 060807: optical limit
  59. GRB 060807: Swift detection of a burst
  60. GRB 060801: Second Epoch WSRT Radio Observations
  61. IPN triangulation of GRB060805B
  62. GRB 060805: optical upper limit in R
  63. GRB 060805: XRT Team Refined Analysis
  64. GRB 060805: Swift-BAT Refined Analysis
  65. GRB 060805: Swift/UVOT Upper Limits
  66. GRB 060805: P60 Observations
  67. GRB 060805: KAIT observations
  68. GRB 060805 - SDSS Pre-Burst Observations
  69. GRB 060805: Swift detection of a burst
  70. GRB 060804: Swift UVOT observations
  71. GRB 060804: Swift-XRT Team Refined Analysis
  72. GRB 060804: Refined analysis of the Swift-BAT burst
  73. GRB 060804: Swift detection of a burst with a possible UVOT counterpart
  74. GRB 060728: Upper limits of the X-ray emission
  75. GRB 060801: no variability of optical sources
  76. IBAS Alert 3418: not a GRB
  77. GRB 060801: WSRT Radio Observations
  78. GRB 060801: XRT/SDSS Frame Offset and Refined XRT Position
  79. GRB060801: Radio Observations
  80. GRB 051109B: Bright spiral host galaxy at low redshift
  81. GRB 060801: optical observations at FORS2/VLT
  82. GRB 060801: optical observations at Hanle and Calar Alto
  83. GRB060801: optical upper limit in R
  84. GRB 060801: Swift XRT refined analysis
  85. GRB 060801: Refined analysis of the Swift-BAT short hard burst
  86. GRB 060801, optical observation
  87. GRB 060801: Kanazawa Optical Observation
  88. GRB 060801: Swift detection of a short burst
  89. GRB060729: ROTSE-III Observations of the Slow Optical Decay
  90. GRB 060218 / SN 2006aj Nebular Spectrum
  91. IBAS Alert n. 3415: not a GRB
  92. Swift-BAT trigger 221873 is not a GRB or a Transient
  93. GRB 060729 redshift
  94. GRB 060719: TORTOREM optical upper limits
  95. GRB 060729: Swift/UVOT Detections
  96. GRB 060729: Refined analysis of the Swift-BAT burst
  97. GRB 060729: Swift-XRT refined analysis
  98. GRB 060729 : Planned XMM-Newton observation
  99. GRB 060729: Swift/UVOT Observations
  100. GRB 060729: ROTSE-III Detection of Optical Counterpart

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