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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"

28068 results found.

  1. GRB 051105: Swift detection of a short burst
  2. GRB 051016B host spectroscopy and redshift
  3. GRB051016B: optical observation
  4. GRB 051022: RTT150 optical observations
  5. GRB051028: optical observations
  6. GRB051028: Swift/UVOT upper limits
  7. GRB051028: confirmation of the afterglow
  8. GRB051028: WHT optical candidate
  9. GRB051028: Swift XRT Position
  10. GRB 051022: XRT Refined Spectral and Temporal Analysis--Correction
  11. GRB051022: Swift XRT measurement of jet break
  12. GRB051021B: Swift/UVOT Upper limits
  13. GRB 051022: XRT Refined Spectral and Temporal Analysis
  14. GRB051012: Swift-XRT analysis
  15. GRB051021B: Swift XRT refined analysis
  16. GRB051021a: optical observations
  17. GRB 051022: WSRT Radio Detection
  18. GRB051022: host galaxy redshift
  19. GRB 051022: Swift/UVOT Upper Limits
  20. GRB051022: Radio Counterpart
  21. GRB051022: IR observations
  22. GRB 051022: SOAR JKs Observations
  23. GRB051021A: Swift XRT refined analysis
  24. GRB051022: Optical Observations
  25. GRB 051022: Magellan NIR imaging
  26. GRB 051021: PROMPT RcIc Observations
  27. GRB051021b: Magellan IR Imaging
  28. GRB 051021: Correction
  29. GRB 051022, J & K-band observation
  30. GRB 051021, SMARTS optical/IR observations
  31. GRB051022: Swift XRT Position
  32. GRB 051021: P200 Ks Observations
  33. GRB 051021: MDM Upper Limit
  34. GRB051021B: Swift XRT Position
  35. GRB 051021: SOAR NIR Observations
  36. GRB 051021B: Swift detection of a burst
  37. GRB051021: Swift XRT analysis
  38. GRB 051021 : optical afterglow observation at Lulin
  39. GRB 051021: Optical observations and candidate afterglow
  40. Swift-BAT triggered on a posible CR Shower or possible GRB
  41. GRB 050502b: Optical limit
  42. GRB 051016b: Optical limit
  43. Afterglow candidate of GRB 051016B observed at Lulin
  44. GRB 051016b: Gemini Near IR Observations
  45. GRB 051016A: Swift/UVOT upper limits
  46. GRB 051016B: refined analysis of the Swift/XRT data
  47. GRB 051016B: Swift/UVOT detection
  48. GRB 051016B : Optical follow-up at Lulin
  49. GRB 051016B: Swift detection of a soft burst
  50. GRB 051016: Swift-BAT refined analysis
  51. GRB051016 XMM-Newton observation
  52. GRB051016: Swift XRT refined analysis.
  53. GRB 051016: LCO optical and near-IR imaging
  54. GRB 051016: PROMPT Observations
  55. GRB051016: Swift detection of a burst
  56. GRB051006: optical observations
  57. GRB 051012: Swift-BAT detection of burst yesterday
  58. Swift trigger 159578 is not a burst
  59. Swift-BAT Trigger 159578 is a possible burst
  60. GRB 051006: Swift/UVOT Upper Limits
  61. GRB051008: optical candidate
  62. GRB 051008 - a low redshift low-luminosity burst?
  63. GRB051008: optical observation
  64. GRB051008: Swift XRT refined analysis
  65. GRB051008 - Swift UVOT upper limits
  66. GRB 051008: R-band upper limit
  67. GRB051008: Radio Observation
  68. GRB 051008: Swift XRT position
  69. GRB 051008, optical observations
  70. GRB 051008: early Swift XRT analysis
  71. GRB 051008: Swift UVOT Candidate
  72. GRB051008: Swift-BAT detection of a bright burst
  73. GRB 051006: P60 Observations
  74. GRB 051006: XRT refined analysis
  75. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  76. GRB 051006: optical observations at Sierra Nevada
  77. GRB 051006: XRT position
  78. GRB051006: Swift detection of a burst
  79. GRB 050906, summary of radio observations
  80. GRB051001: Swift UVOT Upper Limits
  81. GRB 051001: Swift XRT refined analysis
  82. GRB 051001, optical observations at Mt. John
  83. GRB 051001: I-band limit
  84. GRB 051001: AAT infra-red observations
  85. GRB 051001: Swift-BAT refined analysis
  86. GRB 051001: Swift Detection of a Burst
  87. GRB 050922C: further VLT observations
  88. GRB050922C: UVES/VLT high resolution spectroscopy
  89. GRB050925: Swift/XRT limits
  90. GRB050922C - Swift UVOT preliminary analysis
  91. GRB 050922C: break in the lightcurve
  92. GRB050925: Swift UVOT upper limits
  93. GRB050925: Faulkes Telescope North R-band limit
  94. GRB050925: Swift-BAT detection of a short burst
  95. GRB050922C: TNG spectroscopic observations
  96. GRB050922B: refined XRT analysis
  97. GRB 050922C: Refined redshift
  98. GRB050922B: Swift UVOT early upper limits.
  99. INT 2.5m limit for GRB050922B
  100. GRB 050922B: optical limit

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