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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"

41223 results found.

  1. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  2. Further VLA observations of SGR 1806-20
  3. SGR 1806-20 and extragalactic short-duration GRBs
  4. Further ATCA observations of SGR 1806-20
  5. Fourth Epoch VLA observations of SGR 1806-20
  6. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  7. SGR 1806-20: Temporal and Spectral behavior of radio transient
  8. ATCA observations of SGR 1806-20
  9. SGR 1806-20, RHESSI observations of the 041227 giant flare
  10. Third epoch observations of SGR 1806-20 with VLA
  11. Second Epoch VLA observations of SGR 1806-20
  12. Second-epoch VLA observations of SGR 1806-20
  13. SGR1806: Detection of a Sudden Ionospheric Disturbance
  14. VLA observations of SGR 1806-20
  15. SGR1806 VLA Observations
  16. VLA observations of SGR 1806-20
  17. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  18. GRB 041217: Optical observations
  19. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  20. GRB041219, early time observations
  21. Detection of the SGR 1806-20 giant outburst back-scattered by the
  22. The giant outburst from SGR 1806-20
  23. IPN localization of giant flare from SGR1806-20
  24. Giant flare from SGR 1806-20 detected by INTEGRAL
  25. GRB041228: ROTSE-III Optical Observations
  26. GRB041228: Swift-BAT detection of a burst
  27. GRB041219; RXTE ASM Observations
  28. NIR Observations of GRB 041219
  29. GRB041226: ROTSE-III Optical Observations
  30. GRB041226: Swift-BAT detection of a burst
  31. GRB041223: decay of the afterglow
  32. GRB041224: ROTSE-III Optical Observations
  33. GRB 041224: near-infrared observations with REM
  34. GRB 041223: XRT afterglow spectrum and light curve
  35. GRB 041223 Fluence measured by Swift-BAT
  36. GRB041224: Swift-BAT detection of a soft burst
  37. GRB041223: optical and NIR observations with REM
  38. Swift-BAT Time History of GRB041219
  39. GRB 041219: TAROT optical observations
  40. GRB 041218: TAROT optical observations
  41. GRB 041223: J-band observations of the afterglow
  42. GRB 041223: Detection of Optical Transient with LCO40
  43. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  44. GRB 041219c: PROMPT Observations
  45. GRB041223: ROTSE-III Optical Observations
  46. GRB041223: Swift-BAT detection of a bright long burst
  47. GRB 041218: optical observations
  48. Very high activity of SGR 1806-20
  49. GRB 041219: Second Epoch WSRT Radio Observations
  50. GRB 041219: WSRT Radio Afterglow Detection
  51. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  52. GRB 041218: Optical observations
  53. GRB 041219 : optical follow-up observations
  54. GRB041220: Swift-BAT burst
  55. Deep RAPTOR observations during GRB 041219
  56. GRB 041218 Optical Observations
  57. GRB 041219 Optical Observations
  58. GRB041219c: Third Burst in One Day from Swift-BAT
  59. GRB041219: Optical Afterglow Detection
  60. GRB041219: Continued NIR Observations
  61. GRB041219b: A Swift-BAT burst
  62. GRB 041219 ,optical observation
  63. GRB 041219: Radio Afterglow Detection
  64. GRB 041218 : Radio Observations
  65. GRB 041218: R-band optical observations
  66. GRB041218: Liverpool Telescope optical observations
  67. GRB041218: optical observations
  68. GRB041219: Confirmed NIR Afterglow
  69. GRB041218: Continued P60 Optical Observations
  70. Swift-BAT detection of the bright long burst GRB041219
  71. GRB 041218: Optical Observation
  72. GRB 041219: Infrared Afterglow Candidate
  73. GRB041219, BVRcIc field calibration
  74. GRB 041219: Infrared Afterglow Candidate
  75. GRB041218, BVRcIc field calibration
  76. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  77. GRB041219: P60 Optical Observations
  78. GRB 041219 - A long GRB detected by INTEGRAL
  79. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  80. GRB 041217: PROMPT Observations
  81. GRB041218: optical observations
  82. GRB041217: optical limit 30 min after GRB
  83. GRB 041218; optical candidate
  84. GRB 041218: Optical observations
  85. GRB 041217: LCO40 Optical Observations and Possible Candidates
  86. GRB 041218 - A long GRB detected by integral
  87. GRB041217: Optical Observations
  88. GRB041217: NIR and optical observations with REM
  89. GRB041217: P60 Optical Observations
  90. GRB041217: Infrared Observations
  91. GRB041217: The First GRB Located On-Board Swift
  92. GRB041211: Faulkes Telescope continued optical monitoring
  93. Optical Transient in Lynx not a GRB
  94. Optical transient (GRB?) in Lynx
  95. Optical transient (GRB?) in Lynx, UT Dec 11.4436
  96. GRB041211: Continued P60 Observations
  97. GRB041211: RAPTOR observations
  98. GRB041211: Ashra Prototype optical observation
  99. GRB041211, Faulkes Telescope optical observation
  100. GRB041211, BVRcIc field calibration

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