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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"

19091 results found.

  1. GRB 060908: Swift detection of a burst with a bright optical counterpart
  2. GRB060906 , optical observation
  3. GRB 060906: Early RAPTOR optical limits
  4. GRB 060906, Swift-BAT refined spectral analysis
  5. GRB 060906: Confirmation of P60 Optical Afterglow
  6. GRB 060906 (?): P60 Optical Afterglow Candidate
  7. GRB 060906: Swift detection of a probable burst
  8. GRB060904b, optical observations
  9. GRB 060904B: RTT150 optical observations
  10. GRB060904A: Swift/UVOT optical observations
  11. GRB 060904A: Subaru NIR observation
  12. GRB 060904A: Refined analysis of the Swift-BAT burst
  13. GRB 060904A: Suzaku-XIS and -HXD observation plan
  14. GRB 060904A: P60 Observations
  15. GRB 060904B: TAROT optical counterpart observations
  16. GRB060904B - SDSS Pre-Burst Observations
  17. GRB 060904: TAROT optical observations
  18. GRB 060904B: Swift detection of a burst with optical counterpart
  19. GRB060904 - SDSS Pre-Burst Observations
  20. GRB 060904: Swift detection of a bright burst
  21. GRB060901: Optical observations
  22. 060901: Swift UVOT followup observations
  23. Konus-Wind observation of GRB 060901
  24. GRB 060605, observations using an Integral Field Unit
  25. GRB 060604: VLA Observation
  26. GRB 060605: VLA Observation
  27. GRB 060707: VLA observation
  28. GRB 060825: VLA observations
  29. GRB060826 - SDSS Pre-Burst Observations
  30. GRB 060826(?): Swift detection of a possible burst
  31. GRB 060825: TNG optical observations
  32. GRB 060825: TAROT optical observations
  33. GRB 060825: P60 Observations
  34. GRB 060825: Swift detection of a burst
  35. GRB060801: host galaxy redshift
  36. GRB 060729, SMARTS optical/IR observations
  37. GRB 060814: P60 Observations
  38. GRB 060814: P200 NIR Observations
  39. GRB 060814: VLT optical limits
  40. GRB 060814 - SDSS Pre-Burst Observations
  41. GRB 060814: TAROT optical observations
  42. GRB 060814: Swift detection of a bright burst
  43. GRB 060813: Swift detection of a burst
  44. GRB051109B: Late-time Radio Observations
  45. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  46. GRB 060729: An update on the Swift XRT and UVOT observations
  47. GRB060717: optical observations
  48. GRB 060805B: XRT Team Analysis
  49. VLA Upper Limit on Outburst of SGR 1806-20
  50. GRB060807: optical afterglow candidate
  51. IPN triangulation of GRB060806 (long, exceptionally bright)
  52. GRB060807 - SDSS Pre-burst Observations
  53. GRB 060805B: Swift/UVOT Upper Limits
  54. GRB 060807, optical observation
  55. GRB 060807: Kanazawa R-band observation
  56. GRB 060807: Swift detection of a burst
  57. IPN triangulation of GRB060805B
  58. GRB060805 Liverpool Telescope observations
  59. GRB 060805: Swift-BAT Refined Analysis
  60. GRB 060805: Swift/UVOT Upper Limits
  61. GRB 060805: P60 Observations
  62. GRB 060805 - SDSS Pre-Burst Observations
  63. GRB 060805: Swift detection of a burst
  64. GRB 060804: Swift UVOT observations
  65. GRB 060728: Upper limits of the X-ray emission
  66. GRB 060801: no variability of optical sources
  67. GRB 060801: XRT/SDSS Frame Offset and Refined XRT Position
  68. GRB060801: Radio Observations
  69. GRB 051109B: Bright spiral host galaxy at low redshift
  70. GRB060801: Swift/UVOT Upper Limits
  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 060719: TORTOREM optical upper limits
  75. GRB 060729: Swift/UVOT Observations
  76. GRB 060729: Swift detection of a burst with an UVOT optical counterpart
  77. GRB 060728: Swift/UVOT Upper Limits
  78. GRB 060728, SMARTS optical/IR observations
  79. Swift/XRT preliminary analysis
  80. GRB 060728: Swift detection of a burst
  81. GRB 060714: Swift/UVOT Observations
  82. GRB060719: prompt NIR observations with REM
  83. GRB 060714: NOT observations
  84. GRB 060719: near-infrared afterglow
  85. GRB 060522: VLA observation
  86. GRB 060719: Swift/UVOT Upper Limits
  87. GRB 060719: VLT/ISAAC observations
  88. GRB060719: REM NIR Observations
  89. GRB 060719: VLT observations
  90. GRB 060719: LCO optical observations
  91. GRB 060719: Swift detection of a burst
  92. GRB 060717: Swift XRT refined analysis
  93. GRB060717: Swift/UVOT upper limits
  94. GRB 060717: Swift-BAT refined analysis
  95. GRB060717 - SDSS Pre-burst Observations
  96. GRB 060714: REM infrared observations
  97. GRB 060717, optical observation
  98. GRB 060717: Swift detection of a burst
  99. GRB 060714 : Liverpool Telescope Observations
  100. GRB 060708: VLT spectroscopy

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