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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"

36082 results found.

  1. GRB 060403: Swift/UVOT upper limits
  2. GRB 060403: Refined analysis of the Swift-BAT burst
  3. GRB 060403: Swift detection of a burst
  4. GRB 060322: LNA optical limit
  5. GRB 060218SN 2006aj: optical observations at Rozhen Observatory
  6. GRB 060323 : WIDGET simultaneous optical observations
  7. GRB 060323: Early optical observation at Xinglong
  8. GRB060218, optical observations
  9. GRB 060322: Confirmation of Swift XRT afterglow
  10. GRB 060211A: optical observation
  11. GRB060323: optical limit
  12. GRB060211B: optical observation
  13. GRB060323: NOT optical observations
  14. GRB 060322: IAC80 optical observations
  15. GRB 060322: Swift XRT afterglow candidate
  16. GRB 060323: Swift/UVOT Observations
  17. GRB 060323: optical afterglow confirmed
  18. GRB060323: NOT observations
  19. GRB 060323: Optical Observations
  20. GRB 060323: Tautenburg OT candidate retraction
  21. GRB 060323: Refined analysis of the Swift-BAT burst
  22. GRB 060323: optical observations at TNG
  23. GRB 060323: Swift XRT refined analysis
  24. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  25. GRB 060323: Swift/XRT position
  26. GRB 060322: Refined analysis of the Swift-BAT burst
  27. GRB060323 - SDSS Pre-Burst Observations
  28. GRB 060323: Swift detection of a burst with a possible optical afterglow
  29. GRB 060322: Swift-BAT detection of a 200-sec burst
  30. GRB060219: optical observation
  31. GRB060206: optical observation
  32. GRB060218/SN2006aj: optical observations
  33. GRB 060218/SN 2006aj, LNA optical observation
  34. GRB060218: Refined photometric calibration of comparison stars
  35. GRB 060319: WHT K-band candidate afterglow
  36. GRB 060319: IAC-80 optical observations
  37. GRB060319: Swift XRT refined analysis
  38. GRB 060319: Re-analysis of TNG data
  39. GRB060319: MASTER limit
  40. GRB 060319: Swift-BAT refined analysis
  41. GRB 060319 optical observations at TNG
  42. GRB060319 : Liverpool Telescope optical limit
  43. GRB060319: MASTER optical observation
  44. GRB060319 - SDSS Pre-burst Observations
  45. GRB 060319: Swift detection of a burst
  46. GRB060313: Radio Observations
  47. GRB 060313: early afterglow NIR upper limits with REM
  48. IBAS Alert n. 3221: not a GRB
  49. Konus-Wind observation of GRB 060313
  50. GRB060313: SSO 40inch Observations
  51. GRB 060313: Further analysis of the Swift-BAT bright short hard burst
  52. GRB 060313: PROMPT Observations
  53. GRB 060313: Swift/UVOT Observations
  54. GRB060313:Gemini South Observations
  55. GRB 060313: Swift-XRT team refined analysis
  56. GRB060313: optical observations of the afterglow candidate
  57. GRB 060313: Refined analysis of the Swift-BAT bright short hard burst
  58. GRB 060313, SMARTS optical counterpart?
  59. GRB 060313: Possible optical counterpart
  60. GRB 060313: Swift XRT position
  61. GRB 060313, SMARTS optical/IR observations
  62. GRB060313: optical and near infrared observations with REM
  63. GRB 060313: Swift-BAT detection of a bright short hard burst
  64. GRB060218: SARA Observations of SN2006aj
  65. GRB 060312: Refined analysis of the Swift-BAT burst
  66. GRB 060218/SN 2006aj, high resolution spectra
  67. GRB 060312: Swift XRT team refined analysis
  68. GRB060306: APO Ks-band Imaging Observations
  69. GRB 060312: ROTSE-III Optical Limits
  70. GRB 060312: Swift detection of a burst
  71. IBAS Alert n. 3218 : not a real GRB
  72. GRB 060306: SOAR Ks Observations
  73. Bright short hard GRB 060303: IPN localization and Konus spectrum
  74. GRB 060306: MAGNUM observations
  75. GRB060218: analysis of the XMM-Newton observation
  76. Swift/UVOT observations of GRB060306
  77. GRB 060306: Swift-BAT refined analysis
  78. GRB 060306: Swift-XRT team refined analysis
  79. GRB 060306: PROMPT Observations
  80. GRB 060306: Swift detection of a bright burst
  81. GRB 060218: RTT150 optical observations
  82. GRB060223b: optical limit
  83. GRB060218/SN 2006aj: optical observation in V
  84. GRB060218/SN 2006aj: optical observation
  85. GRB 060121: HST observations
  86. GRB 060218 : GMRT observation [Correction and Improvement]
  87. GRB 060223b: Swift/UVOT Upper Limits
  88. GRB 060218/SN 2006aj: K-380 optical observations
  89. GRB 060218/SN 2006aj, SMARTS optical/IR observations
  90. GRB 060223B: Swift XRT possible afterglow
  91. GRB 060218/SN 2006aj: ABT observations
  92. GRB 060218/SN 2006aj: REM optical and near-infrared observations
  93. GRB 060218 : Radio upper limits from GMRT
  94. GRB 060218/SN 2006aj: WIRO optical observations
  95. GRB 060218/SN 2006aj: RBO optical observations
  96. GRB 060204B: GETS early limit
  97. GRB 060218: Refined analysis of the radio afterglow
  98. GRB 060223A:Xinglong optical limits
  99. GRB 060223B: ART optical limits
  100. GRB 060223B: Swift-BAT refined analysis

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