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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').
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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"

32494 results found.

  1. GRB050117a: Radio Observations
  2. GRB050117a: Refined analysis
  3. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  4. GRB050117: Palomar WIRC Ks-band observations
  5. GRB050117: optical observation
  6. GRB 050117, I-band observations
  7. GRB 050117: Optical observation
  8. GRB050117: Refined XRT position
  9. GRB050117: MASTER optical observations
  10. MASTER:GRB050117 SWIFT
  11. GRB050117: Swift-BAT detection of a long multi-peaked burst
  12. SGR 1806-20: RXTE/PCA pulse frequency during flare
  13. SGR 1806-20: Further low frequency GMRT results
  14. SGR1806-20: Swift-BAT observations of two additional bursts
  15. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  16. Further VLA observations of SGR 1806-20
  17. SGR 1806-20 and extragalactic short-duration GRBs
  18. Fourth Epoch VLA observations of SGR 1806-20
  19. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  20. SGR 1806-20: Temporal and Spectral behavior of radio transient
  21. ATCA observations of SGR 1806-20
  22. SGR 1806-20, RHESSI observations of the 041227 giant flare
  23. Third epoch observations of SGR 1806-20 with VLA
  24. Second Epoch VLA observations of SGR 1806-20
  25. Second-epoch VLA observations of SGR 1806-20
  26. SGR1806: Detection of a Sudden Ionospheric Disturbance
  27. DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
  28. VLA observations of SGR 1806-20
  29. SGR1806 VLA Observations
  30. VLA observations of SGR 1806-20
  31. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  32. GRB 041217: Optical observations
  33. GRB041219, early time observations
  34. The giant outburst from SGR 1806-20
  35. IPN localization of giant flare from SGR1806-20
  36. GRB041228: ROTSE-III Optical Observations
  37. GRB041219; RXTE ASM Observations
  38. NIR Observations of GRB 041219
  39. GRB041226: ROTSE-III Optical Observations
  40. GRB041223: decay of the afterglow
  41. GRB041224: ROTSE-III Optical Observations
  42. GRB 041224: near-infrared observations with REM
  43. GRB 041223: XRT afterglow spectrum and light curve
  44. GRB 041223 Fluence measured by Swift-BAT
  45. GRB041223: optical and NIR observations with REM
  46. Swift-BAT Time History of GRB041219
  47. GRB 041219: TAROT optical observations
  48. GRB 041223: J-band observations of the afterglow
  49. GRB 041223: Detection of Optical Transient with LCO40
  50. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  51. GRB 041219c: PROMPT Observations
  52. GRB041223: ROTSE-III Optical Observations
  53. GRB 041218: optical observations
  54. Very high activity of SGR 1806-20
  55. GRB 041219: Second Epoch WSRT Radio Observations
  56. GRB 041219: WSRT Radio Afterglow Detection
  57. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  58. GRB 041218: Optical observations
  59. GRB 041219 : optical follow-up observations
  60. Deep RAPTOR observations during GRB 041219
  61. GRB 041218 Optical Observations
  62. GRB 041219 Optical Observations
  63. GRB041219: Optical Afterglow Detection
  64. GRB041219: Continued NIR Observations
  65. GRB 041219: Radio Afterglow Detection
  66. GRB 041218 : Radio Observations
  67. GRB 041218: R-band optical observations
  68. GRB041218: Liverpool Telescope optical observations
  69. GRB041218: optical observations
  70. GRB041219: Confirmed NIR Afterglow
  71. Swift-BAT detection of the bright long burst GRB041219
  72. GRB 041218: Optical Observation
  73. GRB 041219: Infrared Afterglow Candidate
  74. GRB041219, BVRcIc field calibration
  75. GRB 041219: Infrared Afterglow Candidate
  76. GRB041218, BVRcIc field calibration
  77. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  78. GRB 041217: PROMPT Observations
  79. GRB041218: optical observations
  80. GRB041217: optical limit 30 min after GRB
  81. GRB 041218; optical candidate
  82. GRB 041218: Optical observations
  83. GRB 041217: LCO40 Optical Observations and Possible Candidates
  84. GRB041217: Optical Observations
  85. GRB041217: NIR and optical observations with REM
  86. GRB041217: Infrared Observations
  87. GRB041217: The First GRB Located On-Board Swift
  88. GRB041211: Faulkes Telescope continued optical monitoring
  89. Optical Transient in Lynx not a GRB
  90. Optical transient (GRB?) in Lynx
  91. GRB041211: Continued P60 Observations
  92. GRB041211, Faulkes Telescope optical observation
  93. GRB041211, BVRcIc field calibration
  94. GRB 041211: Infrared Observations
  95. GRB 041211: Optical follow-up in East Asian region
  96. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  97. GRB041015: Near-Infrared observations
  98. GRB 040924: Afterglow Color
  99. GRB 041006: GETS Optical Afterglow Observation
  100. Summary of the recent bursts from SGR 1806-20

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