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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"

11402 results found.

  1. Swift-BAT detection of a bright outburst from SGR1806-20
  2. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  3. GRB 050319: ROTSE-III Refined Analysis
  4. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  5. GRB 050319: NIR afterglow candidate
  6. GRB 050319:Near IR afterglow
  7. GRB050319: BR optical photometry
  8. GRB 050319: Optical observation
  9. GRB050223: analysis of the XMM-Newton observation
  10. GRB050315: Radio afterglow
  11. GRB 050315: Absorption redshift
  12. GRB 050315: Optical afterglow identification
  13. GRB 050315: Swift XRT Position
  14. Swift-BAT detection of GRB 050315
  15. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  16. GRB 050306: R-band observations
  17. Swift trigger 107518: optical observation
  18. Ongoing activity of SGR 1806-20 after the giant flare
  19. GRB050215B: Late-Time Swift UVOT Observations
  20. INTEGRAL detection of GRB 050223
  21. GRB 050223 : Planned XMM-Newton observation
  22. GRB050223: ROTSE-III Optical Observations
  23. GRB 050219a: Optical observations from LCO
  24. GRB 050215b: Swift XRT Source Variability
  25. GRB 050215b : Lulin follow-up observation
  26. GRB050215B: ROTSE-III optical observations
  27. GRB050215A: ROTSE-III Optical Observations
  28. short/hard GRB 050202, optical observations
  29. GRB 050129: a weak long GRB detected with INTEGRAL
  30. SGR1806-20: Swift-BAT detection of a large normal burst
  31. SGR 1806-20: GMRT results at 240 MHz band.
  32. SGR 1806-20: low frequency GMRT results of 2005 Jan 16.
  33. GRB 050128: Swift XRT prompt afterglow position
  34. GRB050126: Burst Parameters Measured by BAT
  35. GRB 050124 : Lulin R-band follow-up observation
  36. GRB050124: Refined BAT position, spectral and fluence information
  37. Unusual optical transient (GRB ???)
  38. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  39. GRB050117b: Swift-BAT detection of a weak burst
  40. GRB050117: optical observation
  41. GRB050117: Refined XRT position
  42. GRB050117: MASTER optical observations
  43. MASTER:GRB050117 SWIFT
  44. SGR 1806-20: RXTE/PCA pulse frequency during flare
  45. Triangulation of Short Hard GRB050112 (large error box)
  46. SGR 1806-20: Further VLA Observations
  47. SGR 1806-20: Further low frequency GMRT results
  48. SGR 1806-20: Further VLA Observations
  49. SGR1806-20: Swift-BAT observations of two additional bursts
  50. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  51. Further VLA observations of SGR 1806-20
  52. SGR 1806-20 and extragalactic short-duration GRBs
  53. Further ATCA observations of SGR 1806-20
  54. Fourth Epoch VLA observations of SGR 1806-20
  55. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  56. SGR 1806-20: Temporal and Spectral behavior of radio transient
  57. ATCA observations of SGR 1806-20
  58. SGR 1806-20, RHESSI observations of the 041227 giant flare
  59. Third epoch observations of SGR 1806-20 with VLA
  60. Second Epoch VLA observations of SGR 1806-20
  61. Second-epoch VLA observations of SGR 1806-20
  62. SGR1806: Detection of a Sudden Ionospheric Disturbance
  63. DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
  64. VLA observations of SGR 1806-20
  65. SGR1806 VLA Observations
  66. VLA observations of SGR 1806-20
  67. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  68. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  69. Detection of the SGR 1806-20 giant outburst back-scattered by the
  70. The giant outburst from SGR 1806-20
  71. IPN localization of giant flare from SGR1806-20
  72. Giant flare from SGR 1806-20 detected by INTEGRAL
  73. NIR Observations of GRB 041219
  74. GRB041226: ROTSE-III Optical Observations
  75. GRB041226: Swift-BAT detection of a burst
  76. GRB041224: ROTSE-III Optical Observations
  77. GRB041224: Swift-BAT detection of a soft burst
  78. GRB 041223: Detection of Optical Transient with LCO40
  79. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  80. GRB041223: ROTSE-III Optical Observations
  81. Very high activity of SGR 1806-20
  82. GRB 041219: WSRT Radio Afterglow Detection
  83. GRB 041219 : optical follow-up observations
  84. GRB041219c: Third Burst in One Day from Swift-BAT
  85. GRB041219: Optical Afterglow Detection
  86. GRB041218: optical observations
  87. GRB041219: P60 Optical Observations
  88. GRB 041219 - A long GRB detected by INTEGRAL
  89. GRB 041218; optical candidate
  90. GRB 041218: Optical observations
  91. GRB 041218 - A long GRB detected by integral
  92. GRB041217: The First GRB Located On-Board Swift
  93. GRB041211: Continued P60 Observations
  94. GRB 041211: Infrared Observations
  95. GRB 041211: KAIT observations
  96. GRB 041211: Optical follow-up in East Asian region
  97. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  98. GRB041015: Near-Infrared observations
  99. GRB 041006: GETS Optical Afterglow Observation
  100. Summary of the recent bursts from SGR 1806-20

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