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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"

26315 results found.

  1. GRB 051105: Swift detection of a short burst
  2. Recent GRB UBVRcIc field photometry
  3. GRB051028 SARA Observation
  4. GRB051028: optical observations
  5. GRB051028: Swift/UVOT upper limits
  6. GRB051028: Swift XRT Position
  7. GRB051028:MASTER observations
  8. GRB051021B: Swift/UVOT Upper limits
  9. GRB 051021, Optical Observations
  10. GRB 051022: XRT Refined Spectral and Temporal Analysis
  11. GRB051012: Swift-XRT analysis
  12. GRB051021B: Swift XRT refined analysis
  13. GRB 051022, mm counterpart
  14. GRB 051022: Swift/UVOT Upper Limits
  15. GRB051022: Radio Counterpart
  16. GRB051022: IR observations
  17. GRB051021A: Swift XRT refined analysis
  18. GRB051022: Optical Observations
  19. GRB051021b: Magellan IR Imaging
  20. GRB 051021, SMARTS optical/IR observations
  21. GRB051022: Swift XRT Position
  22. GRB 051021: P200 Ks Observations
  23. GRB 051022 (=H3950): SXC Flight Localization is Valid
  24. GRB051021: Swift/UVOT Upper Limits
  25. GRB 051021B: Refined analysis of the Swift-BAT burst
  26. GRB 051022: SSO40 Optical Observations
  27. GRB051022,optical observation
  28. GRB 051021,optical observation
  29. GRB 051021B: Swift detection of a burst
  30. GRB 051021 : optical afterglow observation at Lulin
  31. GRB 051021: Optical observations and candidate afterglow
  32. GRB051021.63
  33. GRB051021.6: MASTER optical observation
  34. GRB051021: A GRB Localized by HETE
  35. Swift-BAT triggered on a posible CR Shower or possible GRB
  36. GRB 051016b: Optical limit
  37. Afterglow candidate of GRB 051016B observed at Lulin
  38. GRB 051016A: Swift/UVOT upper limits
  39. GRB 051016B: refined analysis of the Swift/XRT data
  40. GRB 051016B: Swift/UVOT detection
  41. GRB 051016B,optical observation
  42. GRB 051016B : Optical follow-up at Lulin
  43. GRB 051016B: Refined analysis of the Swift-BAT burst
  44. GRB 051016B: Swift detection of a soft burst
  45. GRB 051016: Swift-BAT refined analysis
  46. GRB051016 XMM-Newton observation
  47. GRB051016: Swift XRT refined analysis.
  48. GRB 051016: PROMPT Observations
  49. GRB051016: Swift detection of a burst
  50. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  51. GRB 051012: Swift-BAT detection of burst yesterday
  52. Swift-BAT Trigger 159578 is a possible burst
  53. GRB 051006: Swift/UVOT Upper Limits
  54. GRB051008: optical candidate
  55. GRB 051008 - a low redshift low-luminosity burst?
  56. GRB051011: bright nebulae near error box
  57. GRB051011: MASTER optical observation
  58. GRB051008: Final refined analysis of the Swift-BAT burst
  59. GRB051008: Radio Observation
  60. GRB 051008, optical observations
  61. GRB 051008: early Swift XRT analysis
  62. GRB 051008: Swift UVOT Candidate
  63. GRB 051006: P60 Observations
  64. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  65. GRB 051006: optical observations at Sierra Nevada
  66. GRB051006: Refined analysis of the Swift-BAT burst
  67. GRB051006: Swift detection of a burst
  68. GRB 050906, summary of radio observations
  69. GRB051001: Swift UVOT Upper Limits
  70. GRB 050925: Second Epoch WSRT Radio Observations
  71. GRB 051001: I-band limit
  72. GRB 051001: AAT infra-red observations
  73. GRB 051001: Swift-BAT refined analysis
  74. GRB 051001: Swift Detection of a Burst
  75. GRB 050820A: NIR photometry at the TNG
  76. GRB050925: Swift/XRT limits
  77. GRB/SGR 050925: IR Observations
  78. GRB 050922C: break in the lightcurve
  79. GRB050925: Swift UVOT upper limits
  80. Refined analysis of the Swift-BAT soft short burst
  81. GRB050925: Faulkes Telescope North R-band limit
  82. GRB050925: Swift-BAT detection of a short burst
  83. GRB050922C: TNG spectroscopic observations
  84. GRB050922B: refined XRT analysis
  85. GRB050922B: Swift UVOT early upper limits.
  86. GRB050922C: Optical Observations
  87. GRB 050922C: Swift XRT refined analysis
  88. HETE Fregate observations of GRB 050922C
  89. GRB 050922C: Swift-BAT refined analysis
  90. GRB 050922B: Swift-BAT refined analysis
  91. GRB 050922C: optical obserations
  92. GRB 050922C: NOT optical observations
  93. GRB 050922C: Swift detection of a bright burst
  94. GRB 050922B: ROTSE-III Optical Limits
  95. GRB 050922B,optical observation
  96. GRB050922B: Swift-BAT detection of a weak long burst
  97. GRB050820B: analysis of the XMM-Newton observation
  98. GRB050916: Swift/UVOT Upper Limits
  99. GRB 050916: Swift-BAT refined analysis
  100. Swift-BAT trigger 155764 is not a GRB

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