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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"

12111 results found.

  1. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  2. Swift-BAT detection of GRB 050401
  3. GRB 050401: Prompt XRT position
  4. GRB050331: No Afterglow Detected
  5. Swift-BAT detection of GRB 050331
  6. Konus-Wind observation of GRB 050326
  7. GRB050326: optical limit 33min before GRB
  8. GRB050319, optical observations
  9. GRB050319: optical observation, March 20-22
  10. Swift-BAT detection of a bright outburst from SGR1806-20
  11. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  12. GRB 050319: ROTSE-III Refined Analysis
  13. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  14. GRB 050319: NIR afterglow candidate
  15. GRB 050319:Near IR afterglow
  16. GRB050319: BR optical photometry
  17. GRB 050319: Optical observation
  18. GRB050223: analysis of the XMM-Newton observation
  19. GRB050315: Radio afterglow
  20. GRB 050315: Absorption redshift
  21. GRB 050315: Optical afterglow identification
  22. GRB 050315: Swift XRT Position
  23. Swift-BAT detection of GRB 050315
  24. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  25. GRB 050306: R-band observations
  26. Swift trigger 107518: optical observation
  27. Ongoing activity of SGR 1806-20 after the giant flare
  28. GRB050215B: Late-Time Swift UVOT Observations
  29. INTEGRAL detection of GRB 050223
  30. GRB 050223 : Planned XMM-Newton observation
  31. GRB050223: ROTSE-III Optical Observations
  32. GRB 050219a: Optical observations from LCO
  33. GRB 050215b: Swift XRT Source Variability
  34. GRB 050215b : Lulin follow-up observation
  35. GRB050215B: ROTSE-III optical observations
  36. GRB050215A: ROTSE-III Optical Observations
  37. short/hard GRB 050202, optical observations
  38. GRB 050129: a weak long GRB detected with INTEGRAL
  39. SGR1806-20: Swift-BAT detection of a large normal burst
  40. SGR 1806-20: GMRT results at 240 MHz band.
  41. SGR 1806-20: low frequency GMRT results of 2005 Jan 16.
  42. GRB 050128: Swift XRT prompt afterglow position
  43. GRB050126: Burst Parameters Measured by BAT
  44. GRB 050124 : Lulin R-band follow-up observation
  45. GRB050124: Refined BAT position, spectral and fluence information
  46. Unusual optical transient (GRB ???)
  47. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  48. GRB050117b: Swift-BAT detection of a weak burst
  49. GRB050117: optical observation
  50. GRB050117: Refined XRT position
  51. GRB050117: MASTER optical observations
  52. MASTER:GRB050117 SWIFT
  53. SGR 1806-20: RXTE/PCA pulse frequency during flare
  54. Triangulation of Short Hard GRB050112 (large error box)
  55. SGR 1806-20: Further VLA Observations
  56. SGR 1806-20: Further low frequency GMRT results
  57. SGR 1806-20: Further VLA Observations
  58. SGR1806-20: Swift-BAT observations of two additional bursts
  59. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  60. Further VLA observations of SGR 1806-20
  61. SGR 1806-20 and extragalactic short-duration GRBs
  62. Further ATCA observations of SGR 1806-20
  63. Fourth Epoch VLA observations of SGR 1806-20
  64. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  65. SGR 1806-20: Temporal and Spectral behavior of radio transient
  66. ATCA observations of SGR 1806-20
  67. SGR 1806-20, RHESSI observations of the 041227 giant flare
  68. Third epoch observations of SGR 1806-20 with VLA
  69. Second Epoch VLA observations of SGR 1806-20
  70. Second-epoch VLA observations of SGR 1806-20
  71. SGR1806: Detection of a Sudden Ionospheric Disturbance
  72. DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
  73. VLA observations of SGR 1806-20
  74. SGR1806 VLA Observations
  75. VLA observations of SGR 1806-20
  76. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  77. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  78. Detection of the SGR 1806-20 giant outburst back-scattered by the
  79. The giant outburst from SGR 1806-20
  80. IPN localization of giant flare from SGR1806-20
  81. Giant flare from SGR 1806-20 detected by INTEGRAL
  82. NIR Observations of GRB 041219
  83. GRB041226: ROTSE-III Optical Observations
  84. GRB041226: Swift-BAT detection of a burst
  85. GRB041224: ROTSE-III Optical Observations
  86. GRB041224: Swift-BAT detection of a soft burst
  87. GRB 041223: Detection of Optical Transient with LCO40
  88. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  89. GRB041223: ROTSE-III Optical Observations
  90. Very high activity of SGR 1806-20
  91. GRB 041219: WSRT Radio Afterglow Detection
  92. GRB 041219 : optical follow-up observations
  93. GRB041219c: Third Burst in One Day from Swift-BAT
  94. GRB041219: Optical Afterglow Detection
  95. GRB041218: optical observations
  96. GRB041219: P60 Optical Observations
  97. GRB 041219 - A long GRB detected by INTEGRAL
  98. GRB 041218; optical candidate
  99. GRB 041218: Optical observations
  100. GRB 041218 - A long GRB detected by integral

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