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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"

6667 results found.

  1. GRB051211A (=H3979): Refined Analysis
  2. GRB 051215: near-infrared observations
  3. GRB 051213: Swift-BAT refined analysis
  4. GRB 051211B: Swift XRT confirmation of the afterglow
  5. GRB 051211B: Swift XRT Observations
  6. GRB 051210: Swift XRT refined analysis
  7. GRB 051117b: NIR observations
  8. GRB051117A : XRT refined analysis
  9. GRB 051117B: Lulin R and I band observation
  10. GRB051114: results of the Swift-XRT observation
  11. GRB051111: XRT preliminary analysis
  12. GRB 051111: Swift-BAT refined analysis
  13. GRB 051111a: IR photometry
  14. GRB 051109B: Swift-BAT refined analysis
  15. GRB051109B: XRT refined analysis
  16. GRB051109A: XRT refined analysis
  17. GRB 051109a: IR Photometry and Astrometry
  18. GRB 051109a: IR Detections
  19. GRB051028: Swift-XRT refined analysis
  20. XRT observations of GRB 051105A
  21. GRB 051021, Optical Observations
  22. Chandra Observations of GRB 051022
  23. GRB051012: Swift-XRT analysis
  24. GRB 051022 Chandra Observations scheduled
  25. GRB 051022: SOAR JKs Observations
  26. GRB051021b: Magellan IR Imaging
  27. GRB 051022, J & K-band observation
  28. GRB 051021: P200 Ks Observations
  29. GRB051021: Swift XRT analysis
  30. GRB 051016b: Gemini Near IR Observations
  31. GRB 051016: Swift-BAT refined analysis
  32. GRB051008: Swift XRT refined analysis
  33. GRB051008: Refined analysis of the Swift-BAT burst
  34. GRB 051006: optical observations at Sierra Nevada
  35. GRB 051001, optical observations at Mt. John
  36. GRB 051001: AAT infra-red observations
  37. GRB 051001: Swift-BAT refined analysis
  38. GRB050925: Swift/XRT limits
  39. GRB/SGR 050925: IR Observations
  40. Refined analysis of the Swift-BAT soft short burst
  41. GRB 050922B: Correction to BAT refined analysis, longer burst
  42. GRB050922C: TNG spectroscopic observations
  43. GRB050922B: refined XRT analysis
  44. GRB050922C: Optical Observations
  45. GRB 050922C: NOT optical observations
  46. GRB050820B: analysis of the XMM-Newton observation
  47. GRB 050916: Swift-BAT refined analysis
  48. Swift-BAT trigger 155764 is not a GRB
  49. GRB050916 : Swift-XRT refined analysis
  50. GRB 050915B: Swift-BAT refined analysis
  51. GRB 050915: Swift-BAT refined analysis
  52. GRB050911: Upper limit on X-ray afterglow
  53. Swift-BAT trigger 155072 ground analysis
  54. GRB 050908: Swift-BAT refined analysis
  55. GRB 050908: Optical observations
  56. GRB 050906: Swift XRT upper limit
  57. GRB 050904: Keck I-band Imaging
  58. GRB 050904: early Swift XRT analysis results
  59. GRB050904: Optical Observations
  60. GRB 050827: Swift XRT preliminary analysis results
  61. GRB 050827: P200 NIR Observations
  62. GRB 050827: Swift-BAT refined analysis
  63. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  64. GRB050822: Swift/UVOT upper limits
  65. GRB 050730, optical observation
  66. GRB050805b: CrAO optical limit
  67. GRB050805a : Null detection report
  68. GRB 050805b: OHP optical limits
  69. GRB 050730: OHP optical observations
  70. GRB 050802 : Lulin Optical follow-up observation
  71. GRB 050730: XRT refined analysis
  72. Swift/UVOT photometry of GRB050730
  73. GRB 050730, optical candidate
  74. GRB 050724: Chandra Observations of the X-ray Afterglow
  75. GRB050713: analysis of the XMM-Newton observation
  76. GRB 050724 : Lulin early R-band monitoring observations
  77. GRB 050714a: Refined XRT analysis and afterglow confirmation
  78. GRB 050714B: refined XRT analysis
  79. GRB 050713A: XRT refined analysis
  80. GRB050712: TNG R-band observations
  81. GRB 050713b : Lulin R-band observations
  82. GRB 050713: ARC NIR Detections and Identification of Fading
  83. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  84. GRB 050626: Swift XRT observations
  85. GRB 050408: ARC 3.5-meter NIR Observations
  86. GRB 050603 - XRT data analysis of the first day
  87. GRB 050603: INTEGRAL shows it is not a short GRB
  88. GRB 050525a, infrared observations
  89. GRB 050509b: refined XRT/Chandra afterglow position analysis
  90. GRB 050525a: SARA Observations
  91. XRF050522: NIR observations of XRT candidate
  92. XRF 050522: Continued NIR P200 Monitoring
  93. XRF050522: Near-infrared Observations
  94. XRF050509C: Chandra Afterglow Detection
  95. XRF 050509c: Swift XRT Upper Limit
  96. GRB 050520: P200 Observations
  97. GRB 050520: OSN optical observations
  98. GRB 050504: Swift XRT afterglow candidate has faded
  99. Refined Chandra analysis of GRB 050509b
  100. Chandra observation of GRB 050509b

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