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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"

27394 results found.

  1. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  2. GRB051211A (=H3979): Refined Analysis
  3. Swift detection of an RS CVn flare star
  4. Swift Trigger 172767 is not a GRB
  5. GRB 051215: near-infrared observations
  6. GRB 051215: Swift detection of a possible burst
  7. GRB 051215: A short GRB in a cluster?
  8. GRB051105: optical observations
  9. GRB 051213: Swift-BAT refined analysis
  10. GRB051211B: XRT refined analysis
  11. GRB 051213: Swift-BAT detection of a burst
  12. GRB 051211A: Swift/UVOT upper limits
  13. GRB 051211B: Swift/UVOT upper limits
  14. GRB051211B: Liverpool Telescope observation
  15. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  16. GRB 051210: Swift/UVOT upper limits
  17. HETE SXC localization of GRB 051211 (=H3979)
  18. GRB 051210: BAT further refined analysis of the short burst
  19. GRB 051210: Swift XRT refined analysis
  20. GRB 051210: Swift-BAT refined analysis of a short burst
  21. GRB051210: Swift UVOT Observation
  22. GRB 051210: Swift detection of a burst
  23. An extraordinary long burst on December 3 from SGR1806-20
  24. Possible resuming of the SGR 1806-20 activity
  25. Swift-BAT trigger 165579 is not a GRB
  26. GRB 051127: Swift-BAT detection of a possible burst
  27. GRB051117b: No Swift/UVOT Detection
  28. GRB 051117A: Swift/UVOT Detection of an Afterglow
  29. GRB051111: Rc optical observations
  30. GRB051008: Suzaku WAM observation of the prompt emission
  31. GRB 051021 Optical Observations
  32. GRB 051117B: MARGE Optical Limits
  33. GRB 051117A: Refined analysis of the Swift-BAT burst
  34. GRB 051117B: Refined analysis of the Swift-BAT burst
  35. GRB051117A : XRT refined analysis
  36. GRB 051117B,optical observation
  37. GRB 051117B: Optical observations
  38. GRB 051117B: ROTSE-III Optical Limits
  39. GRB051117B: Swift XRT position
  40. GRB 051117B: Swift detection of a burst
  41. GRB 051117: Swift detection of a bright burst
  42. GRB051114: results of the Swift-XRT observation
  43. GRB 051028 Optical Observations
  44. GRB 051114: Radio Observations
  45. GRB 051114: Swift-BAT refined analysis
  46. GRB050925: analysis of the XMM-Newton observation
  47. GRB 051114: Swift-BAT detection of a short burst
  48. GRB 051113: Swift-BAT refined analysis
  49. GRB 051113: Swift-BAT detection of a burst
  50. GRB 051111: AEOS optical observations
  51. GRB/SGR 050925: XMM-Newton ToO observation
  52. GRB051111: Swift/UVOT Observations
  53. GRB051111: XRT preliminary analysis
  54. GRB 051111: Swift-BAT refined analysis
  55. GRB 051109A Optical Observations
  56. GRB051111a: SARA Observations
  57. GRB 051111A: KAIT optical observations
  58. GRB051111: Super-LOTIS Early Detection
  59. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  60. Faulkes Telescope R-band detection of GRB051111
  61. GRB051111: Swift-BAT detection of a bright burst
  62. GRB 051111A: ROTSE-III Detection of Possible Counterpart
  63. GRB 051109B. Radio Observations
  64. GRB 051105a: GETS optical limit
  65. GRB 051109b: GETS observation
  66. Early RAPTOR measurements of GRB 051109a - the movie.
  67. Konus-Wind observation of GRB 051109A
  68. GRB 051109B: Swift-BAT refined analysis
  69. GRB 051109B: ROTSE-III Optical Limits
  70. GRB 051109A: Swift-UVOT Observations
  71. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  72. GRB051109B: no UVOT source detected
  73. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  74. GRB051109B: XRT position
  75. GRB 051109B: Super-LOTIS Observations
  76. GRB 051109B Kiso optical follow-up observation
  77. GRB 051109B: Swift detection of a burst
  78. GRB 051109: HET Optical Spectrum and Absorption Redshift
  79. GRB051109: Early Super-LOTIS Detection
  80. GRB 051109: Swift-BAT refined analysis
  81. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  82. GRB051109: Swift detection of a burst
  83. GRB 051109a: IR Detections
  84. GRB 051109: ROTSE-III Detection of Possible Counterpart
  85. GRB051105B: Swift/XRT upper limit
  86. GRB051105B: Swift/UVOT upper limit
  87. GRB051103: optical observations
  88. GRB051028: Swift-XRT refined analysis
  89. GRB 051105a, observation from Naini Tal and OSN
  90. GRB 051105a: MDM Observations
  91. GRB051105A: Swift/UVOT Observations
  92. GRB 051105A, radio observations
  93. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  94. XRT observations of GRB 051105A
  95. GRB 051105: Swift-BAT improved refined analysis
  96. GRB 051105b: ART optical limits
  97. GRB 051105B (INTEGRAL 2701): Optical observation
  98. GRB 051105: Swift-BAT refined analysis
  99. GRB 051105: Optical limit
  100. GRB 051105: Swift detection of a short burst

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