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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"

28049 results found.

  1. GRB 050319 : Confirmation of optical afterglow decay
  2. GRB 050319: Swift-BAT refined analysis
  3. GRB050319,optical observation
  4. GRB 050318: Swift/UVOT detection of afterglow emission
  5. RXTE Observations of GRB050318
  6. GRB050223: analysis of the XMM-Newton observation
  7. GRB050316: MASTER before, simultanious and follow up optical
  8. GRB 050306: ROTSE-III early limits
  9. GRB050316: MASTER optical observations
  10. GRB 050315: Swift-BAT further refined analysis
  11. GRB 050315 I-band observations
  12. GRB050315: Radio afterglow
  13. GRB050315: Swift-BAT Refined analysis
  14. Non-detection of GRB050315 in ATCA Radio Observations
  15. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  16. GRB 050315: Early Observations with Swift/UVOT
  17. GRB 050306: Radio Observations
  18. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  19. GRB 050306: optical afterglow
  20. Swift-BAT trigger 107873: No Swift XRT counterpart
  21. GRB 050306: Confirmation of X-ray afterglow
  22. GRB 050306: further TAROT optical data
  23. GRB050309: Early optical limit from P60
  24. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  25. GRB 050309 : Lulin R-band observation
  26. Swift 107873: P60 Optical Observations
  27. GRB 050306: R-band observations
  28. GRB 050306: REM optical-infrared observations
  29. GRB 050306: Possible X-ray Afterglow Position from the Swift
  30. GRB 050306: TAROT optical observations
  31. GRB 050306,optical observation
  32. Ongoing activity of SGR 1806-20 after the giant flare
  33. GRB050215B: Late-Time Swift UVOT Observations
  34. PROMPT VRcIc Observations of GRB 050223
  35. XRF/GRB 050215B: Radio Observations
  36. XMM-Newton Images of GRB 050223
  37. GRB 050219b: candidate NIR afterglow
  38. Confirmed XRF nature for GRB050215b
  39. GRB050223 XMM-Newton observation
  40. INTEGRAL detection of GRB 050223
  41. GRB050223: ROTSE-III Optical Observations
  42. GRB 050223 Swift/BAT detection of a burst
  43. GRB 050223: Swift XRT Position
  44. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  45. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  46. GRB 050219a: Optical observations from LCO
  47. GRB 050219b: Optical and near-IR observations from LCO
  48. GRB 050219b: Swift-BAT detection of a burst
  49. GRB 050219b: CORRECTION: Swift XRT Position
  50. GRB 050219b: Swift XRT Position
  51. GRB 050219: Swift-BAT detection of a burst
  52. GRB 050215b: XRT confirmation of IR afterglow candidate
  53. GRB050215b: P60 Optical Observations
  54. GRB 050215b: Swift XRT Source Variability
  55. GRB 050215B: candidate afterglow
  56. GRB 050215b : Lulin follow-up observation
  57. GRB 050215b, BOOTES-2 simultaneous optical observations
  58. GRB050215A: ROTSE-III Optical Observations
  59. GRB050209: TAROT optical observations
  60. GRB 050209(=U11568): Duration and spectrum
  61. GRB050209: REM optical observations
  62. GRB 050209 I-band observation
  63. GRB 050209 Optical observations
  64. GRB050209: P60 Optical Observations
  65. GRB 050128: Radio observations
  66. Further analysis of the short Swift-BAT GRB 050202
  67. GRB 050202: Short burst detected by Swift-BAT
  68. GRB 050128 Optical observation with REM
  69. SGR1806-20: Swift-BAT detection of a large normal burst
  70. GRB 050128: near-infrared observations with REM
  71. GRB050128,optical observations
  72. GRB050128 Swift-BAT observations
  73. GRB 050128: Swift XRT prompt afterglow position
  74. GRB050126: MASTER optical limit for KECK OT
  75. GRB050126: Burst Parameters Measured by BAT
  76. GRB050126: MASTER optical observations
  77. GRB 050124 I-band observation
  78. GRB050124,optical observation
  79. GRB 050124 : Lulin R-band follow-up observation
  80. GRB050124: Updated Swift XRT Position and Fluxes
  81. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  82. GRB050124: Refined BAT position, spectral and fluence information
  83. GRB 050123 : I-band follow-up observation
  84. GRB050123,optical observation
  85. GRB 050123: KAIT observations
  86. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  87. GRB050117: Refined XRT position
  88. GRB050117: MASTER optical observations
  89. MASTER:GRB050117 SWIFT
  90. GRB050117: Swift XRT Position
  91. Triangulation of Short Hard GRB050112 (large error box)
  92. SGR 1806-20: Further VLA Observations
  93. SGR1806-20: Swift-BAT observations of two additional bursts
  94. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  95. Further VLA observations of SGR 1806-20
  96. SGR 1806-20 and extragalactic short-duration GRBs
  97. Further ATCA observations of SGR 1806-20
  98. Fourth Epoch VLA observations of SGR 1806-20
  99. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  100. ATCA observations of SGR 1806-20

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