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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"

35343 results found.

  1. GRB 060814: Refined analysis of the Swift-BAT burst
  2. GRB 060814: P60 Observations
  3. GRB 060814: P200 NIR Observations
  4. GRB 060814: source inside revised XRT error box
  5. GRB 060814: Possible IR counterpart
  6. GRB060805B: optical observations
  7. GRB060814: Swift/UVOT upper limits
  8. GRB 060813: pseudo-z from spectral parameters of the prompt
  9. GRB 060814: Swift XRT refined analysis
  10. GRB 060814: VLT optical limits
  11. GRB 060814 - SDSS Pre-Burst Observations
  12. GRB 060814: TAROT optical observations
  13. GRB 060814: Swift detection of a bright burst
  14. Konus-Wind observation of GRB 060813
  15. GRB060813: Swift/UVOT upper limits
  16. GRB 060813: Swift XRT refined analysis
  17. GRB 060813: Refined analysis of the Swift-BAT burst
  18. GRB 060813: Swift detection of a burst
  19. GRB051109B: Late-time Radio Observations
  20. Second VLA limit on new radio point source in SGR 1806-20
  21. GRB 060805B: pseudo-z from spectral parameters of the prompt emission
  22. GRB060714: optical observations
  23. IBAS Alert n. 3422: not a GRB
  24. GRB 060729: An update on the Swift XRT and UVOT observations
  25. GRB060717: optical observations
  26. GRB060807: Optical limiting magnitudes
  27. GRB 060805B: optical observation at Sierra Nevada
  28. GRB 060805B: XRT Team Analysis
  29. VLA Upper Limit on Outburst of SGR 1806-20
  30. GRB 060807: UVOT Upper limits
  31. GRB 060807: afterglow confirmation
  32. GRB 060807: XRT Team refined analysis
  33. GRB 060807: K- and R-band observations
  34. GRB 060807: Refined analysis of the Swift-BAT burst
  35. GRB060807: optical afterglow candidate
  36. GRB 060805B: RHESSI Spectral Fit
  37. GRB060807: optical upper limit in white light
  38. IPN triangulation of GRB060806 (long, exceptionally bright)
  39. GRB060807 - SDSS Pre-burst Observations
  40. GRB 060805B: X-ray Afterglow Detection, Spectral/Spatial/Temporal Properties
  41. GRB 060805B: Swift/UVOT Upper Limits
  42. GRB 060807, optical observation
  43. GRB 060807: Kanazawa R-band observation
  44. GRB 060807: optical limit
  45. GRB 060807: Swift detection of a burst
  46. GRB 060801: Second Epoch WSRT Radio Observations
  47. IPN triangulation of GRB060805B
  48. GRB 060805: optical upper limit in R
  49. GRB 060805: XRT Team Refined Analysis
  50. GRB 060805: Swift-BAT Refined Analysis
  51. GRB 060805: Swift/UVOT Upper Limits
  52. GRB 060805: P60 Observations
  53. GRB 060805: KAIT observations
  54. GRB 060805 - SDSS Pre-Burst Observations
  55. GRB 060805: Swift detection of a burst
  56. GRB 060804: Swift UVOT observations
  57. GRB 060804: Swift-XRT Team Refined Analysis
  58. GRB 060804: Refined analysis of the Swift-BAT burst
  59. GRB 060804: Swift detection of a burst with a possible UVOT counterpart
  60. GRB 060728: Upper limits of the X-ray emission
  61. GRB 060801: no variability of optical sources
  62. IBAS Alert 3418: not a GRB
  63. GRB 060801: WSRT Radio Observations
  64. GRB 060801: XRT/SDSS Frame Offset and Refined XRT Position
  65. GRB060801: Radio Observations
  66. GRB 051109B: Bright spiral host galaxy at low redshift
  67. GRB 060801: optical observations at FORS2/VLT
  68. GRB 060801: optical observations at Hanle and Calar Alto
  69. GRB060801: optical upper limit in R
  70. GRB 060801: Swift XRT refined analysis
  71. GRB 060801: Refined analysis of the Swift-BAT short hard burst
  72. GRB 060801, optical observation
  73. GRB 060801: Kanazawa Optical Observation
  74. GRB 060801: Swift detection of a short burst
  75. GRB060729: ROTSE-III Observations of the Slow Optical Decay
  76. GRB 060218 / SN 2006aj Nebular Spectrum
  77. IBAS Alert n. 3415: not a GRB
  78. Swift-BAT trigger 221873 is not a GRB or a Transient
  79. GRB 060729 redshift
  80. GRB 060719: TORTOREM optical upper limits
  81. GRB 060729: Swift/UVOT Detections
  82. GRB 060729: Refined analysis of the Swift-BAT burst
  83. GRB 060729: Swift-XRT refined analysis
  84. GRB 060729 : Planned XMM-Newton observation
  85. GRB 060729: Swift/UVOT Observations
  86. GRB 060729: ROTSE-III Detection of Optical Counterpart
  87. GRB 060729: Swift detection of a burst with an UVOT optical counterpart
  88. GRB 060728: Swift/UVOT Upper Limits
  89. GRB 060728: Refined analysis of the Swift-BAT burst
  90. GRB 060728, SMARTS optical/IR observations
  91. GRB 060728: Swift detection of a burst
  92. GRB060614 ATCA Radio Limits
  93. GRB 060218 (SN 2006aj): IR afterglow detection six months after the
  94. GRB 060714: Swift/UVOT Observations
  95. GRB 060714: NOT observations
  96. GRB 060719: near-infrared afterglow
  97. GRB 060719: correction to the coordinates reported in GCN 5347
  98. GRB 060522: VLA observation
  99. GRB 060719: Swift/UVOT Upper Limits
  100. GRB 060719: VLT/ISAAC observations

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