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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"

20256 results found.

  1. GRB 051109A Optical Observations
  2. GRB 051111a: IR photometry
  3. GRB 051109B. Radio Observations
  4. GRB 051109A
  5. GRB051109A - radio observations
  6. Early RAPTOR measurements of GRB 051109a - the movie.
  7. GRB 051109B: ROTSE-III Optical Limits
  8. GRB 051109A: Swift-UVOT Observations
  9. GRB051109B: no UVOT source detected
  10. GRB 051109B: Super-LOTIS Observations
  11. GRB051105B: REM Optical observation
  12. GRB 051109: PROMPT Detections
  13. GRB 051109: Rc and Ic observations
  14. GRB 051109: Swift-BAT refined analysis
  15. GRB 051109a: IR Photometry and Astrometry
  16. GRB051109: Swift detection of a burst
  17. GRB 051109a: IR Detections
  18. GRB051105B: Swift/XRT upper limit
  19. GRB051105B: Swift/UVOT upper limit
  20. GRB 051105a, observation from Naini Tal and OSN
  21. GRB 051105a: MDM Observations
  22. GRB 051105A: TNG optical observations
  23. GRB051105A: Swift/UVOT Observations
  24. GRB 051105A, radio observations
  25. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  26. XRT observations of GRB 051105A
  27. GRB 051105b: ART optical limits
  28. GRB051105B - A long GRB detected by INTEGRAL
  29. GRB 051105: Optical limit
  30. GRB 051105: Swift detection of a short burst
  31. Recent GRB UBVRcIc field photometry
  32. GRB051028 SARA Observation
  33. GRB051028: Swift/UVOT upper limits
  34. GRB051028: Swift XRT Position
  35. GRB051021B: Swift/UVOT Upper limits
  36. GRB 051021, Optical Observations
  37. GRB 051022, refined optical astrometry
  38. GRB051012: Swift-XRT analysis
  39. GRB 051022: Swift/UVOT Upper Limits
  40. GRB051022: Radio Counterpart
  41. GRB051022: IR observations
  42. GRB051021A: Swift XRT refined analysis
  43. Konus-Wind observation of GRB 051022
  44. GRB051022: Optical Observations
  45. GRB 051021: PROMPT RcIc Observations
  46. GRB051021b: Magellan IR Imaging
  47. GRB 051022: Spectral Analysis Indicates That The Spectrum Is Absorbed
  48. GRB051022: Swift XRT Position
  49. GRB 051021: P200 Ks Observations
  50. GRB 051021: MDM Upper Limit
  51. GRB 051022 (=H3950): SXC Flight Localization is Valid
  52. GRB051021: Swift/UVOT Upper Limits
  53. GRB 051022: SSO40 Optical Observations
  54. GRB051022,optical observation
  55. GRB 051022A: ROTSE-III Optical Limits
  56. GRB 051022: Optical observations
  57. GRB 051021,optical observation
  58. GRB 051021B: Swift detection of a burst
  59. Swift-BAT triggered on a posible CR Shower or possible GRB
  60. Afterglow candidate of GRB 051016B observed at Lulin
  61. GRB 051016A: Swift/UVOT upper limits
  62. GRB 051016B: Swift/UVOT detection
  63. GRB 051016B,optical observation
  64. GRB 051016B: Swift detection of a soft burst
  65. GRB051016 XMM-Newton observation
  66. GRB 051016: PROMPT Observations
  67. GRB051016: Swift detection of a burst
  68. GRB051006: optical observations
  69. GRB 051012: Swift-BAT detection of burst yesterday
  70. GRB 051006: Swift/UVOT Upper Limits
  71. GRB051011: MASTER optical observation
  72. Konus-Wind observation of GRB 051008
  73. GRB051008: Radio Observation
  74. GRB 051008, optical observations
  75. GRB 051008: early Swift XRT analysis
  76. GRB 051008: Swift UVOT Candidate
  77. GRB 051006: P60 Observations
  78. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  79. GRB051006: Refined analysis of the Swift-BAT burst
  80. GRB051006: Swift detection of a burst
  81. GRB 050906, summary of radio observations
  82. GRB051001: Swift UVOT Upper Limits
  83. GRB 051001: AAT infra-red observations
  84. GRB 051001: Swift Detection of a Burst
  85. GRB 051001: ROTSE-III Optical Limits
  86. GRB 050820A: NIR photometry at the TNG
  87. GRB/SGR 050925: IR Observations
  88. GRB050925: Swift UVOT upper limits
  89. GRB050925: Faulkes Telescope North R-band limit
  90. GRB050925: Swift-BAT detection of a short burst
  91. GRB050922C: TNG spectroscopic observations
  92. Konus-Wind observation of GRB 050922C
  93. GRB050922B: Swift UVOT early upper limits.
  94. GRB050922C: Optical Observations
  95. GRB 050922C: Swift-BAT refined analysis
  96. GRB 050922C: optical obserations
  97. GRB 050922C: NOT optical observations
  98. GRB 050922C: Swift detection of a bright burst
  99. GRB 050922C: ROTSE-IIId Refined Analysis
  100. GRB 050922B: ROTSE-III Optical Limits

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