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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"

3402 results found.

  1. GRB060403: XRT refined analysis
  2. GRB 060322: Confirmation of Swift XRT afterglow
  3. GRB 060322: Swift XRT afterglow candidate
  4. GRB 060313: early afterglow NIR upper limits with REM
  5. GRB 060312: Swift XRT team refined analysis
  6. GRB060306: APO Ks-band Imaging Observations
  7. GRB 060306: SOAR Ks Observations
  8. GRB060218: analysis of the XMM-Newton observation
  9. GRB 060223B: Swift XRT possible afterglow
  10. GRB 060223: Swift/UVOT Confirmation of Optical Afterglow
  11. GRB 060219: Swift-XRT Team refined analysis
  12. GRB 051221B: Swift-XRT Team Refined Analysis
  13. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  14. GRB 060211B: Swift-XRT Team refined analysis
  15. GRB060210: Swift XRT Refined Analysis
  16. GRB 060206: near-infrared observations (JK' imaging)
  17. GRB 060206: IR Detection of the Afterglow
  18. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  19. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  20. Swift XRT Observation of GRB 060204C
  21. GRB060204B: Swift XRT Team Refined Analysis
  22. GRB 060203: IR Counterpart
  23. Swift BAT Trigger 180151: Swift XRT source detection
  24. GRB 060121: Confirmation of NIR Afterglow
  25. GRB 060123: Swift refined analysis of an unusual GRB
  26. GRB060105: refined analysis of the Suzaku observation
  27. GRB 060121: Probable Detection of NIR Afterglow
  28. GRB060124: detailed XRT analysis
  29. GRB060123: Optical and IR Imaging
  30. GRB 060123: Swift detection of a very long, faint burst
  31. GRB 060121: Swift/UVOT upper limits
  32. GRB 060121: Swift XRT refined analysis
  33. GRB 060121: Swift XRT refined position
  34. GRB 060121: Infrared Observations
  35. GRB 060116: possible I-J dropout
  36. GRB 060110: XRT position and analysis
  37. GRB 060114: Swift XRT upper limit
  38. GRB 060108: further analysis of VLT images
  39. GRB 060111B: Swift XRT refined analysis
  40. GRB060111 : XRT refined analysis
  41. GRB 060110: IR Candidate Afterglow
  42. GRB 060108: ISAS early observations and near IR upper limit
  43. GRB060108: P200 Ks Observations
  44. GRB 060105: ISAS observations and near IR upper limit
  45. Swift-BAT trigger 175653 is not an astrophysical source
  46. GRB051016: analysis of the XMM-Newton observation
  47. GRB 051221A: Chandra Afterglow Position
  48. GRB 051221: Swift XRT refined analysis
  49. GRB 051215: near-infrared observations
  50. GRB 051211B: Swift XRT confirmation of the afterglow
  51. GRB 051211B: Swift XRT Observations
  52. GRB 051210: Swift XRT refined analysis
  53. GRB 051117b: NIR observations
  54. GRB051117A : XRT refined analysis
  55. GRB051114: results of the Swift-XRT observation
  56. GRB051111: XRT preliminary analysis
  57. GRB 051111a: IR photometry
  58. GRB051109B: XRT refined analysis
  59. GRB051109A: XRT refined analysis
  60. GRB 051109a: IR Photometry and Astrometry
  61. GRB 051109a: IR Detections
  62. GRB051028: Swift-XRT refined analysis
  63. XRT observations of GRB 051105A
  64. GRB 051022: XRT Refined Spectral and Temporal Analysis
  65. Chandra Observations of GRB 051022
  66. GRB051012: Swift-XRT analysis
  67. GRB 051022 Chandra Observations scheduled
  68. GRB 051022: SOAR JKs Observations
  69. GRB 051022, J & K-band observation
  70. GRB 051021: P200 Ks Observations
  71. GRB051021: Swift XRT analysis
  72. GRB 051016b: Gemini Near IR Observations
  73. GRB051008: Swift XRT refined analysis
  74. GRB 051001: AAT infra-red observations
  75. GRB 051001: ROTSE-III Optical Limits
  76. GRB050925: Swift/XRT limits
  77. GRB/SGR 050925: IR Observations
  78. GRB050922B: refined XRT analysis
  79. GRB050820B: analysis of the XMM-Newton observation
  80. Swift-BAT trigger 155764 is not a GRB
  81. GRB050916 : Swift-XRT refined analysis
  82. GRB050911: Upper limit on X-ray afterglow
  83. Swift-BAT trigger 155072 ground analysis
  84. GRB 050906: Swift XRT upper limit
  85. GRB 050904: early Swift XRT analysis results
  86. GRB 050827: Swift XRT preliminary analysis results
  87. GRB 050827: P200 NIR Observations
  88. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  89. GRB 050730: XRT refined analysis
  90. GRB 050724: Chandra Observations of the X-ray Afterglow
  91. GRB050713: analysis of the XMM-Newton observation
  92. GRB 050714a: Refined XRT analysis and afterglow confirmation
  93. GRB 050713: ARC NIR Detections and Identification of Fading
  94. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  95. GRB 050626: Swift XRT observations
  96. GRB 050408: ARC 3.5-meter NIR Observations
  97. GRB 050603 - XRT data analysis of the first day
  98. GRB 050525a, infrared observations
  99. GRB 050509b: refined XRT/Chandra afterglow position analysis
  100. XRF050522: NIR observations of XRT candidate

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