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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

45651 results found.

  1. GRB 060413: Watcher UBVR observations
  2. GRB 060413: XRT refined analysis
  3. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  4. GRB 060413: Swift detection of a burst
  5. GRB060403: optical observations
  6. GRB 060403 Optical observations
  7. GRB 060403: MITSuME optical observation
  8. GRB060403: Optical Limit
  9. GRB060403: XRT refined analysis
  10. GRB 060403: Swift/UVOT upper limits
  11. HETE Triggers H4043 and H4044 Not Due to New Cosmic Source
  12. SGR 1900+14: BAT observations
  13. GRB 060403: Refined analysis of the Swift-BAT burst
  14. GRB060403: Swift XRT refined position
  15. Konus-Wind observation of the recent SGR 1900+14 activity. Will
  16. GRB 060403: Swift detection of a burst
  17. HETE trigger H4044: RTT150 optical observations
  18. GRB060331: Swift/UVOT upper limits
  19. H4044, a Repeat Outburst From The Source of H4043 (="GRB060331")
  20. Swift XRT observations of the HETE transient H4043
  21. HETE Trigger 4043: ROTSE-III Optical Limits
  22. Correction to Circular 4938, =H4043, an unusual high energy transient observed by HETE
  23. H4043, an unusual high-energy transient observed by HETE
  24. GRB 060322: LNA optical limit
  25. SGR 1900+14: bright burst detected by Konus-Wind on March 28
  26. INTEGRAL and XMM ToO observations of SGR1900+14
  27. SGR 1900+14: Swift-BAT detection of a cluster of outbursts
  28. SGR 1900+14: Swift-BAT detection of a bright outburst
  29. GRB 060218SN 2006aj: optical observations at Rozhen Observatory
  30. GRB 060323 : WIDGET simultaneous optical observations
  31. GRB 060323: Early optical observation at Xinglong
  32. GRB060218, optical observations
  33. GRB 060322: Confirmation of Swift XRT afterglow
  34. GRB 060211A: optical observation
  35. GRB060323: optical limit
  36. GRB060211B: optical observation
  37. SGR 1900+14: CORRECTION to GCN 4923
  38. SGR 1900+14: Refined Swift-BAT analysis of the renewed activity
  39. SGR 1900+14: Swift detection of renewed activity
  40. GRB060323: NOT optical observations
  41. GRB 060322: IAC80 optical observations
  42. GRB 060322: Swift XRT afterglow candidate
  43. GRB060323: P60 Observations
  44. GRB 060323: Swift/UVOT Observations
  45. GRB 060323: optical afterglow confirmed
  46. GRB060323: NOT observations
  47. GRB 060323: Optical Observations
  48. GRB 060323: Tautenburg OT candidate retraction
  49. GRB 060323: Refined analysis of the Swift-BAT burst
  50. GRB 060323: optical observations at TNG
  51. GRB 060323: Swift XRT refined analysis
  52. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  53. GRB 060323: Swift/XRT position
  54. GRB 060322: Refined analysis of the Swift-BAT burst
  55. GRB060323, optical observation
  56. GRB060323 - SDSS Pre-Burst Observations
  57. GRB 060323: Swift detection of a burst with a possible optical afterglow
  58. GRB 060322: Swift-BAT detection of a 200-sec burst
  59. GRB060219: optical observation
  60. GRB060206: optical observation
  61. GRB060218/SN2006aj: optical observations
  62. GRB 060218/SN 2006aj, LNA optical observation
  63. GRB060218: Refined photometric calibration of comparison stars
  64. GRB 060319: WHT K-band candidate afterglow
  65. GRB 060319: IAC-80 optical observations
  66. GRB060319: Swift XRT refined analysis
  67. GRB060319: Swift/UVOT upper limits
  68. GRB 060319: Re-analysis of TNG data
  69. GRB060319: MASTER limit
  70. GRB 060319: Swift-BAT refined analysis
  71. GRB 060319 optical observations at TNG
  72. GRB060319 : Liverpool Telescope optical limit
  73. GRB060319: MASTER optical observation
  74. GRB060319 - SDSS Pre-burst Observations
  75. GRB060319: Swift/XRT position
  76. GRB 060319: Swift detection of a burst
  77. GRB060313: Radio Observations
  78. GRB 060313: early afterglow NIR upper limits with REM
  79. IBAS Alert n. 3221: not a GRB
  80. Konus-Wind observation of GRB 060313
  81. GRB060313: SSO 40inch Observations
  82. GRB 060313: Further analysis of the Swift-BAT bright short hard burst
  83. GRB 060313: PROMPT Observations
  84. GRB 060313: Swift/UVOT Observations
  85. GRB060313:Gemini South Observations
  86. GRB 060313: Swift-XRT team refined analysis
  87. GRB060313: optical observations of the afterglow candidate
  88. GRB 060313: Refined analysis of the Swift-BAT bright short hard burst
  89. GRB 060313, SMARTS optical counterpart?
  90. GRB 060313: Possible optical counterpart
  91. GRB 060313: Swift XRT position
  92. GRB 060313, SMARTS optical/IR observations
  93. GRB060313: optical and near infrared observations with REM
  94. GRB 060313: Swift-BAT detection of a bright short hard burst
  95. GRB060218: SARA Observations of SN2006aj
  96. GRB060312: Swift UVOT observation
  97. GRB 060312: Refined analysis of the Swift-BAT burst
  98. GRB 060218/SN 2006aj, high resolution spectra
  99. GRB 060312: Swift XRT team refined analysis
  100. GRB060306: APO Ks-band Imaging Observations

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