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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"

6474 results found.

  1. GRB 051221B: Optical Observations with Kuiper 1.54m
  2. GRB 051227: Swift/UVOT Upper Limits (Possible U-band
  3. GRB051016: analysis of the XMM-Newton observation
  4. GRB 051221A: Chandra Afterglow Position
  5. GRB 051221B: Refined analysis of the Swift-BAT burst
  6. GRB 051221: Swift XRT refined analysis
  7. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  8. GRB051211A (=H3979): Refined Analysis
  9. GRB 051215: near-infrared observations
  10. GRB 051213: Swift-BAT refined analysis
  11. GRB 051211B: Swift XRT confirmation of the afterglow
  12. GRB 051211B: Swift XRT Observations
  13. GRB 051210: Swift XRT refined analysis
  14. GRB 051117b: NIR observations
  15. GRB051117A : XRT refined analysis
  16. GRB 051117B: Lulin R and I band observation
  17. GRB051114: results of the Swift-XRT observation
  18. GRB051111: XRT preliminary analysis
  19. GRB 051111: Swift-BAT refined analysis
  20. GRB 051111a: IR photometry
  21. GRB 051109B: Swift-BAT refined analysis
  22. GRB051109B: XRT refined analysis
  23. GRB051109A: XRT refined analysis
  24. GRB 051109a: IR Photometry and Astrometry
  25. GRB 051109a: IR Detections
  26. GRB051028: Swift-XRT refined analysis
  27. XRT observations of GRB 051105A
  28. GRB 051021, Optical Observations
  29. Chandra Observations of GRB 051022
  30. GRB051012: Swift-XRT analysis
  31. GRB 051022 Chandra Observations scheduled
  32. GRB 051022: SOAR JKs Observations
  33. GRB051021b: Magellan IR Imaging
  34. GRB 051022, J & K-band observation
  35. GRB 051021: P200 Ks Observations
  36. GRB051021: Swift XRT analysis
  37. GRB 051016b: Gemini Near IR Observations
  38. GRB 051016: Swift-BAT refined analysis
  39. GRB051008: Swift XRT refined analysis
  40. GRB051008: Refined analysis of the Swift-BAT burst
  41. GRB 051006: optical observations at Sierra Nevada
  42. GRB 051001, optical observations at Mt. John
  43. GRB 051001: AAT infra-red observations
  44. GRB 051001: Swift-BAT refined analysis
  45. GRB050925: Swift/XRT limits
  46. GRB/SGR 050925: IR Observations
  47. Refined analysis of the Swift-BAT soft short burst
  48. GRB 050922B: Correction to BAT refined analysis, longer burst
  49. GRB050922C: TNG spectroscopic observations
  50. GRB050922B: refined XRT analysis
  51. GRB050922C: Optical Observations
  52. GRB 050922C: NOT optical observations
  53. GRB050820B: analysis of the XMM-Newton observation
  54. GRB 050916: Swift-BAT refined analysis
  55. Swift-BAT trigger 155764 is not a GRB
  56. GRB050916 : Swift-XRT refined analysis
  57. GRB 050915B: Swift-BAT refined analysis
  58. GRB 050915: Swift-BAT refined analysis
  59. GRB050911: Upper limit on X-ray afterglow
  60. Swift-BAT trigger 155072 ground analysis
  61. GRB 050908: Swift-BAT refined analysis
  62. GRB 050908: Optical observations
  63. GRB 050906: Swift XRT upper limit
  64. GRB 050904: Keck I-band Imaging
  65. GRB 050904: early Swift XRT analysis results
  66. GRB050904: Optical Observations
  67. GRB 050827: Swift XRT preliminary analysis results
  68. GRB 050827: P200 NIR Observations
  69. GRB 050827: Swift-BAT refined analysis
  70. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  71. GRB050822: Swift/UVOT upper limits
  72. GRB 050730, optical observation
  73. GRB050805b: CrAO optical limit
  74. GRB050805a : Null detection report
  75. GRB 050805b: OHP optical limits
  76. GRB 050730: OHP optical observations
  77. GRB 050802 : Lulin Optical follow-up observation
  78. GRB 050730: XRT refined analysis
  79. Swift/UVOT photometry of GRB050730
  80. GRB 050730, optical candidate
  81. GRB 050724: Chandra Observations of the X-ray Afterglow
  82. GRB050713: analysis of the XMM-Newton observation
  83. GRB 050724 : Lulin early R-band monitoring observations
  84. GRB 050714a: Refined XRT analysis and afterglow confirmation
  85. GRB 050714B: refined XRT analysis
  86. GRB 050713A: XRT refined analysis
  87. GRB050712: TNG R-band observations
  88. GRB 050713b : Lulin R-band observations
  89. GRB 050713: ARC NIR Detections and Identification of Fading
  90. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  91. GRB 050626: Swift XRT observations
  92. GRB 050408: ARC 3.5-meter NIR Observations
  93. GRB 050603 - XRT data analysis of the first day
  94. GRB 050603: INTEGRAL shows it is not a short GRB
  95. GRB 050525a, infrared observations
  96. GRB 050509b: refined XRT/Chandra afterglow position analysis
  97. GRB 050525a: SARA Observations
  98. XRF050522: NIR observations of XRT candidate
  99. XRF 050522: Continued NIR P200 Monitoring
  100. XRF050522: Near-infrared Observations

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