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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"

28055 results found.

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

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