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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"

26363 results found.

  1. GRB050326: delayed XRT observation
  2. GRB050319, color indices
  3. GRB050319: optical observation, March 20-22
  4. GRB050319: RTT150 Optical Observations
  5. Swift-BAT trigger 112060 is not a real GRB
  6. GRB 050318: Swift-BAT refined analysis
  7. GRB050319: VLA Observations
  8. GRB050319: radio observation
  9. GRB 050319: Swift-UVOT detection of the afterglow
  10. GRB 050315: Variability Analysis of Swift BAT Time History
  11. GRB050319: Radio Observations
  12. GRB 050319: NIR afterglow candidate
  13. GRB 050319:Near IR afterglow
  14. GRB 050318: SWIFT-UVOT refined analysis
  15. GRB 050319 : Confirmation of optical afterglow decay
  16. GRB 050319: Swift-BAT refined analysis
  17. GRB050319,optical observation
  18. GRB 050318: Swift/UVOT detection of afterglow emission
  19. RXTE Observations of GRB050318
  20. GRB050223: analysis of the XMM-Newton observation
  21. GRB050316: MASTER before, simultanious and follow up optical
  22. GRB 050306: ROTSE-III early limits
  23. GRB050316: MASTER optical observations
  24. GRB 050315: Swift-BAT further refined analysis
  25. GRB 050315 I-band observations
  26. GRB050315: Radio afterglow
  27. GRB050315: Swift-BAT Refined analysis
  28. Non-detection of GRB050315 in ATCA Radio Observations
  29. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  30. GRB 050315: Early Observations with Swift/UVOT
  31. GRB 050306: Radio Observations
  32. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  33. GRB 050306: optical afterglow
  34. Swift-BAT trigger 107873: No Swift XRT counterpart
  35. GRB 050306: Confirmation of X-ray afterglow
  36. GRB 050306: further TAROT optical data
  37. GRB050309: Early optical limit from P60
  38. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  39. GRB 050309 : Lulin R-band observation
  40. Swift 107873: P60 Optical Observations
  41. GRB 050306: R-band observations
  42. GRB 050306: REM optical-infrared observations
  43. GRB 050306: Possible X-ray Afterglow Position from the Swift
  44. GRB 050306: TAROT optical observations
  45. GRB 050306,optical observation
  46. Ongoing activity of SGR 1806-20 after the giant flare
  47. GRB050215B: Late-Time Swift UVOT Observations
  48. PROMPT VRcIc Observations of GRB 050223
  49. XRF/GRB 050215B: Radio Observations
  50. XMM-Newton Images of GRB 050223
  51. GRB 050219b: candidate NIR afterglow
  52. Confirmed XRF nature for GRB050215b
  53. GRB050223 XMM-Newton observation
  54. INTEGRAL detection of GRB 050223
  55. GRB050223: ROTSE-III Optical Observations
  56. GRB 050223 Swift/BAT detection of a burst
  57. GRB 050223: Swift XRT Position
  58. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  59. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  60. GRB 050219a: Optical observations from LCO
  61. GRB 050219b: Optical and near-IR observations from LCO
  62. GRB 050219b: Swift-BAT detection of a burst
  63. GRB 050219b: CORRECTION: Swift XRT Position
  64. GRB 050219b: Swift XRT Position
  65. GRB 050219: Swift-BAT detection of a burst
  66. GRB 050215b: XRT confirmation of IR afterglow candidate
  67. GRB050215b: P60 Optical Observations
  68. GRB 050215b: Swift XRT Source Variability
  69. GRB 050215B: candidate afterglow
  70. GRB 050215b : Lulin follow-up observation
  71. GRB 050215b, BOOTES-2 simultaneous optical observations
  72. GRB050215A: ROTSE-III Optical Observations
  73. GRB050209: TAROT optical observations
  74. GRB 050209(=U11568): Duration and spectrum
  75. GRB050209: REM optical observations
  76. GRB 050209 I-band observation
  77. GRB 050209 Optical observations
  78. GRB050209: P60 Optical Observations
  79. GRB 050128: Radio observations
  80. Further analysis of the short Swift-BAT GRB 050202
  81. GRB 050202: Short burst detected by Swift-BAT
  82. GRB 050128 Optical observation with REM
  83. SGR1806-20: Swift-BAT detection of a large normal burst
  84. GRB 050128: near-infrared observations with REM
  85. GRB050128,optical observations
  86. GRB050128 Swift-BAT observations
  87. GRB 050128: Swift XRT prompt afterglow position
  88. GRB050126: MASTER optical limit for KECK OT
  89. GRB050126: Burst Parameters Measured by BAT
  90. GRB050126: MASTER optical observations
  91. GRB 050124 I-band observation
  92. GRB050124,optical observation
  93. GRB 050124 : Lulin R-band follow-up observation
  94. GRB050124: Updated Swift XRT Position and Fluxes
  95. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  96. GRB050124: Refined BAT position, spectral and fluence information
  97. GRB 050123 : I-band follow-up observation
  98. GRB050123,optical observation
  99. GRB 050123: KAIT observations
  100. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations

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