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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"

37784 results found.

  1. SGR 1900+14: Refined analysis of the Swift-BAT outburst
  2. GRB060413: Swift/UVOT upper limits
  3. GRB 060413: REM NIR Observations
  4. SGR 1900+14: Swift detection of an outburst
  5. GRB 060413: Refined analysis of the Swift-BAT burst
  6. GRB 060413: Watcher UBVR observations
  7. GRB 060413: XRT refined analysis
  8. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  9. GRB 060413: Swift detection of a burst
  10. GRB060403: optical observations
  11. GRB 060403 Optical observations
  12. GRB 060403: MITSuME optical observation
  13. GRB060403: XRT refined analysis
  14. GRB 060403: Swift/UVOT upper limits
  15. SGR 1900+14: BAT observations
  16. GRB 060403: Refined analysis of the Swift-BAT burst
  17. GRB060403: Swift XRT refined position
  18. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  19. GRB 060403: Swift detection of a burst
  20. GRB060331: Swift/UVOT upper limits
  21. Swift XRT observations of the HETE transient H4043
  22. GRB 060322: LNA optical limit
  23. SGR 1900+14: bright burst detected by Konus-Wind on March 28
  24. SGR 1900+14: Swift-BAT detection of a cluster of outbursts
  25. SGR 1900+14: Swift-BAT detection of a bright outburst
  26. GRB 060218SN 2006aj: optical observations at Rozhen Observatory
  27. GRB 060323 : WIDGET simultaneous optical observations
  28. GRB 060323: Early optical observation at Xinglong
  29. GRB060218, optical observations
  30. GRB 060322: Confirmation of Swift XRT afterglow
  31. GRB 060211A: optical observation
  32. GRB060323: optical limit
  33. GRB060211B: optical observation
  34. SGR 1900+14: CORRECTION to GCN 4923
  35. SGR 1900+14: Refined Swift-BAT analysis of the renewed activity
  36. SGR 1900+14: Swift detection of renewed activity
  37. GRB060323: NOT optical observations
  38. GRB 060322: IAC80 optical observations
  39. GRB 060322: Swift XRT afterglow candidate
  40. GRB 060323: Swift/UVOT Observations
  41. GRB 060323: optical afterglow confirmed
  42. GRB060323: NOT observations
  43. GRB 060323: Optical Observations
  44. GRB 060323: Tautenburg OT candidate retraction
  45. GRB 060323: Refined analysis of the Swift-BAT burst
  46. GRB 060323: optical observations at TNG
  47. GRB 060323: Swift XRT refined analysis
  48. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  49. GRB 060323: Swift/XRT position
  50. GRB 060322: Refined analysis of the Swift-BAT burst
  51. GRB060323 - SDSS Pre-Burst Observations
  52. GRB 060323: Swift detection of a burst with a possible optical afterglow
  53. GRB 060322: Swift-BAT detection of a 200-sec burst
  54. GRB060219: optical observation
  55. GRB060206: optical observation
  56. GRB060218/SN2006aj: optical observations
  57. GRB 060218/SN 2006aj, LNA optical observation
  58. GRB060218: Refined photometric calibration of comparison stars
  59. GRB 060319: WHT K-band candidate afterglow
  60. GRB 060319: IAC-80 optical observations
  61. GRB060319: Swift XRT refined analysis
  62. GRB060319: Swift/UVOT upper limits
  63. GRB 060319: Re-analysis of TNG data
  64. GRB060319: MASTER limit
  65. GRB 060319: Swift-BAT refined analysis
  66. GRB 060319 optical observations at TNG
  67. GRB060319 : Liverpool Telescope optical limit
  68. GRB060319: MASTER optical observation
  69. GRB060319 - SDSS Pre-burst Observations
  70. GRB060319: Swift/XRT position
  71. GRB 060319: Swift detection of a burst
  72. GRB060313: Radio Observations
  73. GRB 060313: early afterglow NIR upper limits with REM
  74. IBAS Alert n. 3221: not a GRB
  75. Konus-Wind observation of GRB 060313
  76. GRB060313: SSO 40inch Observations
  77. GRB 060313: Further analysis of the Swift-BAT bright short hard burst
  78. GRB 060313: PROMPT Observations
  79. GRB 060313: Swift/UVOT Observations
  80. GRB060313:Gemini South Observations
  81. GRB 060313: Swift-XRT team refined analysis
  82. GRB060313: optical observations of the afterglow candidate
  83. GRB 060313: Refined analysis of the Swift-BAT bright short hard burst
  84. GRB 060313, SMARTS optical counterpart?
  85. GRB 060313: Possible optical counterpart
  86. GRB 060313: Swift XRT position
  87. GRB 060313, SMARTS optical/IR observations
  88. GRB060313: optical and near infrared observations with REM
  89. GRB 060313: Swift-BAT detection of a bright short hard burst
  90. GRB060218: SARA Observations of SN2006aj
  91. GRB060312: Swift UVOT observation
  92. GRB 060312: Refined analysis of the Swift-BAT burst
  93. GRB 060218/SN 2006aj, high resolution spectra
  94. GRB 060312: Swift XRT team refined analysis
  95. GRB060306: APO Ks-band Imaging Observations
  96. GRB 060312: ROTSE-III Optical Limits
  97. GRB 060312: Swift detection of a burst
  98. IBAS Alert n. 3218 : not a real GRB
  99. GRB 060306: SOAR Ks Observations
  100. Bright short hard GRB 060303: IPN localization and Konus spectrum

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