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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"

35255 results found.

  1. Konus-Wind observation of GRB 051022
  2. GRB051022: Optical Observations
  3. GRB 051022: Magellan NIR imaging
  4. GRB 051021: PROMPT RcIc Observations
  5. GRB051021b: Magellan IR Imaging
  6. GRB 051022: Spectral Analysis Indicates That The Spectrum Is Absorbed
  7. GRB 051021: Correction
  8. GRB 051022, J & K-band observation
  9. GRB 051021, SMARTS optical/IR observations
  10. GRB 051021: P200 Ks Observations
  11. IPN triangulation of GRB051022 (=H3950)
  12. GRB 051021: MDM Upper Limit
  13. GRB 051022 (=H3950): SXC Flight Localization is Valid
  14. GRB051021: Swift/UVOT Upper Limits
  15. GRB 051021B: Refined analysis of the Swift-BAT burst
  16. GRB 051022: SSO40 Optical Observations
  17. GRB 051022A: ROTSE-III Optical Limits
  18. GRB051022 (=H3590), A GRB Detected By HETE
  19. GRB 051022: Optical observations
  20. GRB 051021,optical observation
  21. GRB051021B: Swift XRT Position
  22. GRB 051021: SOAR NIR Observations
  23. GRB 051021B: Swift detection of a burst
  24. GRB051021 (=H3947): Refined Analysis
  25. GRB 051021 : optical afterglow observation at Lulin
  26. GRB 051021: Optical observations
  27. GRB 051021: ROTSE-III Confirmation of Optical Counterpart
  28. GRB 051021: Optical observations and candidate afterglow
  29. GRB051021.63
  30. GRB051021.6: MASTER optical observation
  31. Swift-BAT trigger 160640 is not a real GRB
  32. GRB051021: A GRB Localized by HETE
  33. Swift-BAT trigger 160619 is not a GRB
  34. Swift-BAT triggered on a posible CR Shower or possible GRB
  35. GRB 050502b: Optical limit
  36. GRB 051016b: Optical limit
  37. Afterglow candidate of GRB 051016B observed at Lulin
  38. GRB 051016b: Gemini Near IR Observations
  39. GRB 051016A: Swift/UVOT upper limits
  40. GRB 051016B: refined analysis of the Swift/XRT data
  41. GRB 051016B: Swift/UVOT detection
  42. GRB 051016B,optical observation
  43. GRB 051016B : Optical follow-up at Lulin
  44. GRB 051016B: Refined analysis of the Swift-BAT burst
  45. GRB 051016B: Swift detection of a soft burst
  46. GRB 051016: Swift-BAT refined analysis
  47. GRB051016: Swift XRT refined analysis.
  48. GRB 051016: LCO optical and near-IR imaging
  49. GRB 051016: PROMPT Observations
  50. GRB051016: Swift detection of a burst
  51. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  52. GRB051006: optical observations
  53. GRB 051012: Swift-BAT detection of burst yesterday
  54. Swift trigger 159578 is not a burst
  55. GRB 051006: Swift/UVOT Upper Limits
  56. IBAS Alert 2675 : not a GRB
  57. GRB051008: optical candidate
  58. GRB 051008: - a high redshift high-luminosity burst?
  59. GRB 051008 - a low redshift low-luminosity burst?
  60. IBAS Alert 2673: not a real GRB
  61. GRB051011: MASTER optical observation
  62. GRB051008: optical observation
  63. GRB051008: Swift XRT refined analysis
  64. GRB051008 - Swift UVOT upper limits
  65. Konus-Wind observation of GRB 051008
  66. GRB051008: Final refined analysis of the Swift-BAT burst
  67. GRB 051008: R-band upper limit
  68. GRB051008: Radio Observation
  69. GRB 051008: Swift XRT position
  70. GRB 051008, optical observations
  71. GRB 051008: early Swift XRT analysis
  72. GRB 051008: Swift UVOT Candidate
  73. GRB 051006: P60 Observations
  74. grb test
  75. GRB 051006: XRT refined analysis
  76. GRB 051006: optical observations at Sierra Nevada
  77. GRB 051006: XRT position
  78. GRB 050906, summary of radio observations
  79. GRB 050925: Second Epoch WSRT Radio Observations
  80. GRB 051001: Swift XRT refined analysis
  81. GRB 051001, optical observations at Mt. John
  82. GRB 051001: I-band limit
  83. GRB 051001: AAT infra-red observations
  84. GRB 051001: Swift-BAT refined analysis
  85. GRB 051001: Swift Detection of a Burst
  86. GRB 051001: ROTSE-III Optical Limits
  87. GRB050908: optical observations
  88. GRB050922C: optical observation
  89. GRB050922B: optical limit
  90. GRB 050922C: further VLT observations
  91. GRB 050820A: NIR photometry at the TNG
  92. GRB050922C: UVES/VLT high resolution spectroscopy
  93. GRB050925: Swift/XRT limits
  94. GRB/SGR 050925: IR Observations
  95. GRB 050922C: break in the lightcurve
  96. GRB 050925: WSRT Radio Observations
  97. GRB 050925 : I-band observation at Xinglong observatory
  98. GRB050925: Faulkes Telescope North R-band limit
  99. GRB050925: Swift-BAT detection of a short burst
  100. GRB 050922B: Correction to BAT refined analysis, longer burst

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