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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"

12090 results found.

  1. GRB 050315: Swift XRT Position
  2. Swift-BAT detection of GRB 050315
  3. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  4. GRB 050306: R-band observations
  5. Swift trigger 107518: optical observation
  6. Ongoing activity of SGR 1806-20 after the giant flare
  7. GRB050215B: Late-Time Swift UVOT Observations
  8. INTEGRAL detection of GRB 050223
  9. GRB 050223 : Planned XMM-Newton observation
  10. GRB050223: ROTSE-III Optical Observations
  11. GRB 050219a: Optical observations from LCO
  12. GRB 050215b: Swift XRT Source Variability
  13. GRB 050215b : Lulin follow-up observation
  14. GRB050215B: ROTSE-III optical observations
  15. GRB050215A: ROTSE-III Optical Observations
  16. short/hard GRB 050202, optical observations
  17. GRB 050129: a weak long GRB detected with INTEGRAL
  18. SGR1806-20: Swift-BAT detection of a large normal burst
  19. SGR 1806-20: GMRT results at 240 MHz band.
  20. SGR 1806-20: low frequency GMRT results of 2005 Jan 16.
  21. GRB 050128: Swift XRT prompt afterglow position
  22. GRB050126: Burst Parameters Measured by BAT
  23. GRB 050124 : Lulin R-band follow-up observation
  24. GRB050124: Refined BAT position, spectral and fluence information
  25. Unusual optical transient (GRB ???)
  26. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  27. GRB050117b: Swift-BAT detection of a weak burst
  28. GRB050117: optical observation
  29. GRB050117: Refined XRT position
  30. GRB050117: MASTER optical observations
  31. MASTER:GRB050117 SWIFT
  32. SGR 1806-20: RXTE/PCA pulse frequency during flare
  33. Triangulation of Short Hard GRB050112 (large error box)
  34. SGR 1806-20: Further VLA Observations
  35. SGR 1806-20: Further low frequency GMRT results
  36. SGR 1806-20: Further VLA Observations
  37. SGR1806-20: Swift-BAT observations of two additional bursts
  38. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  39. Further VLA observations of SGR 1806-20
  40. SGR 1806-20 and extragalactic short-duration GRBs
  41. Further ATCA observations of SGR 1806-20
  42. Fourth Epoch VLA observations of SGR 1806-20
  43. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  44. SGR 1806-20: Temporal and Spectral behavior of radio transient
  45. ATCA observations of SGR 1806-20
  46. SGR 1806-20, RHESSI observations of the 041227 giant flare
  47. Third epoch observations of SGR 1806-20 with VLA
  48. Second Epoch VLA observations of SGR 1806-20
  49. Second-epoch VLA observations of SGR 1806-20
  50. SGR1806: Detection of a Sudden Ionospheric Disturbance
  51. DETECTION OF POLARIZATION OF THE RADIO EMISSION FROM SGR 1806-20
  52. VLA observations of SGR 1806-20
  53. SGR1806 VLA Observations
  54. VLA observations of SGR 1806-20
  55. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  56. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  57. Detection of the SGR 1806-20 giant outburst back-scattered by the
  58. The giant outburst from SGR 1806-20
  59. IPN localization of giant flare from SGR1806-20
  60. Giant flare from SGR 1806-20 detected by INTEGRAL
  61. NIR Observations of GRB 041219
  62. GRB041226: ROTSE-III Optical Observations
  63. GRB041226: Swift-BAT detection of a burst
  64. GRB041224: ROTSE-III Optical Observations
  65. GRB041224: Swift-BAT detection of a soft burst
  66. GRB 041223: Detection of Optical Transient with LCO40
  67. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  68. GRB041223: ROTSE-III Optical Observations
  69. Very high activity of SGR 1806-20
  70. GRB 041219: WSRT Radio Afterglow Detection
  71. GRB 041219 : optical follow-up observations
  72. GRB041219c: Third Burst in One Day from Swift-BAT
  73. GRB041219: Optical Afterglow Detection
  74. GRB041218: optical observations
  75. GRB041219: P60 Optical Observations
  76. GRB 041219 - A long GRB detected by INTEGRAL
  77. GRB 041218; optical candidate
  78. GRB 041218: Optical observations
  79. GRB 041218 - A long GRB detected by integral
  80. GRB041217: The First GRB Located On-Board Swift
  81. GRB041211: Continued P60 Observations
  82. GRB 041211: Infrared Observations
  83. GRB 041211: KAIT observations
  84. GRB 041211: Optical follow-up in East Asian region
  85. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  86. GRB041015: Near-Infrared observations
  87. GRB 041006: GETS Optical Afterglow Observation
  88. Summary of the recent bursts from SGR 1806-20
  89. GRB041015, optical observation in CrAO
  90. IBAS GRB Alert # 2034
  91. Bright bursts from SGR1806-20
  92. GRB041016: MASTER: Optical observations
  93. GRB 041015 R band observations
  94. GRB041015: MASTER: Optical observations
  95. GRB041006: Fading X-ray Afterglow Observed with Chandra
  96. GRB 041015: Optical limit at Osaka University
  97. GRB 041015 - A long GRB detected by INTEGRAL
  98. GRB041006, optical observation in CrAO
  99. Search for SN light in XRF 040912 with MEGACAM
  100. GRB 041006 : optical follow-up observation at Lulin Observatory

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