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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"

6472 results found.

  1. GRB051016: analysis of the XMM-Newton observation
  2. GRB 051221A: Chandra Afterglow Position
  3. GRB 051221B: Refined analysis of the Swift-BAT burst
  4. GRB 051221: Swift XRT refined analysis
  5. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  6. GRB051211A (=H3979): Refined Analysis
  7. GRB 051215: near-infrared observations
  8. GRB 051213: Swift-BAT refined analysis
  9. GRB 051211B: Swift XRT confirmation of the afterglow
  10. GRB 051211B: Swift XRT Observations
  11. GRB 051210: Swift XRT refined analysis
  12. GRB 051117b: NIR observations
  13. GRB051117A : XRT refined analysis
  14. GRB 051117B: Lulin R and I band observation
  15. GRB051114: results of the Swift-XRT observation
  16. GRB051111: XRT preliminary analysis
  17. GRB 051111: Swift-BAT refined analysis
  18. GRB 051111a: IR photometry
  19. GRB 051109B: Swift-BAT refined analysis
  20. GRB051109B: XRT refined analysis
  21. GRB051109A: XRT refined analysis
  22. GRB 051109a: IR Photometry and Astrometry
  23. GRB 051109a: IR Detections
  24. GRB051028: Swift-XRT refined analysis
  25. XRT observations of GRB 051105A
  26. GRB 051021, Optical Observations
  27. Chandra Observations of GRB 051022
  28. GRB051012: Swift-XRT analysis
  29. GRB 051022 Chandra Observations scheduled
  30. GRB 051022: SOAR JKs Observations
  31. GRB051021b: Magellan IR Imaging
  32. GRB 051022, J & K-band observation
  33. GRB 051021: P200 Ks Observations
  34. GRB051021: Swift XRT analysis
  35. GRB 051016b: Gemini Near IR Observations
  36. GRB 051016: Swift-BAT refined analysis
  37. GRB051008: Swift XRT refined analysis
  38. GRB051008: Refined analysis of the Swift-BAT burst
  39. GRB 051006: optical observations at Sierra Nevada
  40. GRB 051001, optical observations at Mt. John
  41. GRB 051001: AAT infra-red observations
  42. GRB 051001: Swift-BAT refined analysis
  43. GRB050925: Swift/XRT limits
  44. GRB/SGR 050925: IR Observations
  45. Refined analysis of the Swift-BAT soft short burst
  46. GRB 050922B: Correction to BAT refined analysis, longer burst
  47. GRB050922C: TNG spectroscopic observations
  48. GRB050922B: refined XRT analysis
  49. GRB050922C: Optical Observations
  50. GRB 050922C: NOT optical observations
  51. GRB050820B: analysis of the XMM-Newton observation
  52. GRB 050916: Swift-BAT refined analysis
  53. Swift-BAT trigger 155764 is not a GRB
  54. GRB050916 : Swift-XRT refined analysis
  55. GRB 050915B: Swift-BAT refined analysis
  56. GRB 050915: Swift-BAT refined analysis
  57. GRB050911: Upper limit on X-ray afterglow
  58. Swift-BAT trigger 155072 ground analysis
  59. GRB 050908: Swift-BAT refined analysis
  60. GRB 050908: Optical observations
  61. GRB 050906: Swift XRT upper limit
  62. GRB 050904: Keck I-band Imaging
  63. GRB 050904: early Swift XRT analysis results
  64. GRB050904: Optical Observations
  65. GRB 050827: Swift XRT preliminary analysis results
  66. GRB 050827: P200 NIR Observations
  67. GRB 050827: Swift-BAT refined analysis
  68. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  69. GRB050822: Swift/UVOT upper limits
  70. GRB 050730, optical observation
  71. GRB050805b: CrAO optical limit
  72. GRB050805a : Null detection report
  73. GRB 050805b: OHP optical limits
  74. GRB 050730: OHP optical observations
  75. GRB 050802 : Lulin Optical follow-up observation
  76. GRB 050730: XRT refined analysis
  77. Swift/UVOT photometry of GRB050730
  78. GRB 050730, optical candidate
  79. GRB 050724: Chandra Observations of the X-ray Afterglow
  80. GRB050713: analysis of the XMM-Newton observation
  81. GRB 050724 : Lulin early R-band monitoring observations
  82. GRB 050714a: Refined XRT analysis and afterglow confirmation
  83. GRB 050714B: refined XRT analysis
  84. GRB 050713A: XRT refined analysis
  85. GRB050712: TNG R-band observations
  86. GRB 050713b : Lulin R-band observations
  87. GRB 050713: ARC NIR Detections and Identification of Fading
  88. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  89. GRB 050626: Swift XRT observations
  90. GRB 050408: ARC 3.5-meter NIR Observations
  91. GRB 050603 - XRT data analysis of the first day
  92. GRB 050603: INTEGRAL shows it is not a short GRB
  93. GRB 050525a, infrared observations
  94. GRB 050509b: refined XRT/Chandra afterglow position analysis
  95. GRB 050525a: SARA Observations
  96. XRF050522: NIR observations of XRT candidate
  97. XRF 050522: Continued NIR P200 Monitoring
  98. XRF050522: Near-infrared Observations
  99. XRF050509C: Chandra Afterglow Detection
  100. XRF 050509c: Swift XRT Upper Limit

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