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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 060805B: RHESSI Spectral Fit
  2. GRB060807: optical upper limit in white light
  3. IPN triangulation of GRB060806 (long, exceptionally bright)
  4. GRB060807 - SDSS Pre-burst Observations
  5. GRB 060805B: X-ray Afterglow Detection, Spectral/Spatial/Temporal Properties
  6. GRB 060805B: Swift/UVOT Upper Limits
  7. GRB 060807, optical observation
  8. GRB 060807: Kanazawa R-band observation
  9. GRB 060807: optical limit
  10. GRB 060807: Swift detection of a burst
  11. GRB 060801: Second Epoch WSRT Radio Observations
  12. IPN triangulation of GRB060805B
  13. GRB060805 Liverpool Telescope observations
  14. GRB 060805: optical upper limit in R
  15. GRB 060805: XRT Team Refined Analysis
  16. GRB 060805: Swift-BAT Refined Analysis
  17. GRB 060805: Swift/UVOT Upper Limits
  18. GRB 060805: P60 Observations
  19. GRB 060805: KAIT observations
  20. GRB 060805 - SDSS Pre-Burst Observations
  21. GRB 060805: Swift detection of a burst
  22. GRB 060804: Swift UVOT observations
  23. GRB 060804: Swift-XRT Team Refined Analysis
  24. GRB 060804: Refined analysis of the Swift-BAT burst
  25. GRB 060804: Swift detection of a burst with a possible UVOT counterpart
  26. GRB 060728: Upper limits of the X-ray emission
  27. GRB 060801: no variability of optical sources
  28. IBAS Alert 3418: not a GRB
  29. GRB 060801: WSRT Radio Observations
  30. GRB 060801: XRT/SDSS Frame Offset and Refined XRT Position
  31. GRB060801: Radio Observations
  32. GRB 051109B: Bright spiral host galaxy at low redshift
  33. GRB 060801: optical observations at FORS2/VLT
  34. GRB060801: Swift/UVOT Upper Limits
  35. GRB 060801: optical observations at Hanle and Calar Alto
  36. GRB060801: optical upper limit in R
  37. GRB 060801: Swift XRT refined analysis
  38. GRB 060801: Refined analysis of the Swift-BAT short hard burst
  39. GRB 060801, optical observation
  40. GRB 060801: Kanazawa Optical Observation
  41. GRB 060801: Swift detection of a short burst
  42. GRB060729: ROTSE-III Observations of the Slow Optical Decay
  43. GRB 060218 / SN 2006aj Nebular Spectrum
  44. IBAS Alert n. 3415: not a GRB
  45. Swift-BAT trigger 221873 is not a GRB or a Transient
  46. GRB 060729 redshift
  47. GRB 060719: TORTOREM optical upper limits
  48. GRB 060729: Swift/UVOT Detections
  49. GRB 060729: Refined analysis of the Swift-BAT burst
  50. GRB 060729: Swift-XRT refined analysis
  51. GRB 060729 : Planned XMM-Newton observation
  52. GRB 060729: Swift/UVOT Observations
  53. GRB 060729: ROTSE-III Detection of Optical Counterpart
  54. GRB 060729: Swift detection of a burst with an UVOT optical counterpart
  55. GRB 060728: Swift/UVOT Upper Limits
  56. GRB 060728: Refined analysis of the Swift-BAT burst
  57. GRB 060728, SMARTS optical/IR observations
  58. Swift/XRT preliminary analysis
  59. GRB 060728: Swift detection of a burst
  60. GRB060614 ATCA Radio Limits
  61. GRB 060218 (SN 2006aj): IR afterglow detection six months after the
  62. GRB 060714: Swift/UVOT Observations
  63. GRB060719: prompt NIR observations with REM
  64. GRB 060714: NOT observations
  65. GRB 060719: near-infrared afterglow
  66. GRB 060719: correction to the coordinates reported in GCN 5347
  67. GRB 060522: VLA observation
  68. GRB 060719: Swift/UVOT Upper Limits
  69. GRB 060719: VLT/ISAAC observations
  70. GRB 060719: Refined analysis of the Swift-BAT burst
  71. GRB 060719: XRT refined analysis
  72. GRB 060719: further analysis of VLT observations
  73. GRB 060719: optical limit by Pi-of-the-Sky
  74. GRB060719: FRAM early follow-up limit
  75. GRB 060719: prompt PROMPT observations
  76. GRB060719: REM NIR Observations
  77. GRB 060719: Continued LCO optical observations
  78. GRB 060719: VLT observations
  79. GRB 060719: LCO optical observations
  80. GRB 060719: Swift detection of a burst
  81. GRB 060717: Swift XRT refined analysis
  82. GRB 060714: OA fading and a possible host detection
  83. GRB060714: optical observations
  84. GRB 060717: NOT observations
  85. GRB 060714: Refined analysis of the Swift-BAT burst
  86. GRB 060717 optical upper limit
  87. GRB060717: Swift/UVOT upper limits
  88. GRB 060717: Swift XRT refined position
  89. GRB 060717: Swift-BAT refined analysis
  90. GRB060717 - SDSS Pre-burst Observations
  91. GRB 060714: REM infrared observations
  92. GRB 060717, optical observation
  93. GRB 060717: Swift detection of a burst
  94. GRB060714: correction to GCN 5324
  95. GRB060714: optical observations
  96. GRB 060714, SMARTS optical/IR afterglow observation
  97. GRB 060714 : Liverpool Telescope Observations
  98. GRB 060714: Swift XRT refined analysis
  99. GRB 060714: OA redshift
  100. GRB 060708: VLT spectroscopy

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