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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"

27563 results found.

  1. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  2. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  3. short/hard GRB 050202, optical observations
  4. GRB 050128: Radio observations
  5. GRB 050128 Optical observation with REM
  6. SGR1806-20: Swift-BAT detection of a large normal burst
  7. GRB050128: Faulkes Telescope South observations
  8. GRB 050124: Radio Observations
  9. GRB 050128: near-infrared observations with REM
  10. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  11. GRB050126: Updated Swift XRT Position
  12. SGR 1806-20: GMRT results at 240 MHz band.
  13. SGR 1806-20: low frequency GMRT results of 2005 Jan 16.
  14. GRB 050126: Radio Observations
  15. GRB050128 Swift-BAT observations
  16. GRB 050128: Swift XRT prompt afterglow position
  17. GRB 050124: K-band afterglow observations
  18. GRB050126: MASTER optical limit for KECK OT
  19. GRB050126: Burst Parameters Measured by BAT
  20. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  21. GRB 050126: Prompt XRT detection and localization
  22. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  23. GRB050124: No Swift UVOT Detection of Afterglow Emission
  24. GRB 050124, SMARTS optical/IR observations
  25. GRB 050117a: Radio Observations
  26. GRB 050124: NIR Candidates from Keck/NIRC
  27. GRB050124: Updated Swift XRT Position and Fluxes
  28. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  29. CFHTLS optical transient unlikely to be a GRB
  30. Unusual optical transient (GRB ???)
  31. GRB050117a: Radio Observations
  32. GRB050117: Palomar WIRC Ks-band observations
  33. GRB050117b: Swift-BAT detection of a weak burst
  34. GRB050117: optical observation
  35. GRB 050117, I-band observations
  36. GRB 050117: Optical observation
  37. GRB050117: Refined XRT position
  38. GRB050117: Swift-BAT detection of a long multi-peaked burst
  39. GRB050117: Swift XRT Position
  40. SGR 1806-20: Further low frequency GMRT results
  41. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  42. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  43. SGR 1806-20: Temporal and Spectral behavior of radio transient
  44. Second-epoch VLA observations of SGR 1806-20
  45. SGR1806: Detection of a Sudden Ionospheric Disturbance
  46. DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
  47. SGR1806 VLA Observations
  48. GRB 041217: Optical observations
  49. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  50. GRB041219, early time observations
  51. Detection of the SGR 1806-20 giant outburst back-scattered by the
  52. GRB041228: Swift-BAT detection of a burst
  53. GRB041219; RXTE ASM Observations
  54. NIR Observations of GRB 041219
  55. GRB041226: Swift-BAT detection of a burst
  56. GRB041223: decay of the afterglow
  57. GRB 041223: XRT afterglow spectrum and light curve
  58. GRB041224: Swift-BAT detection of a soft burst
  59. GRB041223: optical and NIR observations with REM
  60. Swift-BAT Time History of GRB041219
  61. GRB 041223: J-band observations of the afterglow
  62. GRB 041223: Detection of Optical Transient with LCO40
  63. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  64. GRB041223: Swift-BAT detection of a bright long burst
  65. GRB 041218: optical observations
  66. GRB 041219: WSRT Radio Afterglow Detection
  67. GRB 041218: Optical observations
  68. GRB 041219 : optical follow-up observations
  69. GRB 041219 Optical Observations
  70. GRB041219: Optical Afterglow Detection
  71. GRB041219: Continued NIR Observations
  72. GRB041219b: A Swift-BAT burst
  73. GRB 041219: Radio Afterglow Detection
  74. GRB 041218 : Radio Observations
  75. GRB 041218: R-band optical observations
  76. GRB041218: Liverpool Telescope optical observations
  77. GRB041218: optical observations
  78. GRB041219: Confirmed NIR Afterglow
  79. GRB041218: Continued P60 Optical Observations
  80. Swift-BAT detection of the bright long burst GRB041219
  81. GRB 041219: Infrared Afterglow Candidate
  82. GRB 041219: Infrared Afterglow Candidate
  83. GRB041218, BVRcIc field calibration
  84. GRB041218: optical observations
  85. GRB 041218: Optical observations
  86. GRB 041217: LCO40 Optical Observations and Possible Candidates
  87. GRB041217: Infrared Observations
  88. Optical transient (GRB?) in Lynx
  89. GRB041211, BVRcIc field calibration
  90. GRB041211: P60 optical imaging
  91. GRB970815: Discovery of Optical Afterglow
  92. Distribution of IBAS Alerts for NON-GRB sources
  93. GRB 040924: Afterglow Color
  94. GRB 041006: GETS Optical Afterglow Observation
  95. GRB 041006: Optical Observations
  96. GRB041006, late-time optical photometry
  97. GRB041006: RTT150 Optical Observations
  98. HST Observations: XRF 040701 and 040812
  99. GRB041006: RTT150 Optical Observations
  100. GRB 041016: Optical limits

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