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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"
  1. GRB 060526: Tautenburg OT observation and light curve fitting
  2. GRB060526: optical observations
  3. GRB 060526: SMARTS optical/IR afterglow observations
  4. GRB060526: possible break in the optical light curve
  5. GRB 060526: REM observations
  6. GRB 060526: RTT150 optical observations, afterglow flattening
  7. GRB 060526: Optical Flare
  8. GRB 060526: MDM-2.4m Observations
  9. GRB 060526: Refined analysis of the Swift-BAT burst
  10. GRB 060526: RTT150 optical observations
  11. GRB060526: Further Swift-UVOT Observations
  12. GRB060526, optical observations
  13. GRB 060526: Magellan Redshift
  14. GRB 060526 Lulin optical observation
  15. GRB 060526: Swift/XRT Team refined analysis
  16. GRB 060526: TNG optical observations
  17. GRB 060526: ROTSE-III Observations of Optical Counterpart
  18. GRB 060526: Watcher Observations
  19. GRB060526 - SDSS Pre-burst Observations
  20. GRB 060526: Continued emission for the Swift burst
  21. GRB 060526: Swift detection of a burst with x-ray and optical afterglow
  22. GRB060505: VLT observations of the optical afterglow
  23. GRB 060413 : WIDGET simultaneous optical observations
  24. GRB 060522: Swift/UVOT Observations: Correction
  25. GRB 060522: Swift/UVOT Observations of the Optical Afterglow
  26. XMM-Newton observation of GRB060510b
  27. GRB060512: Late-Time P200 Observations
  28. GRB060522: z = 5.11 Keck-LRIS Redshift
  29. GRB 060522: Swift/XRT Team refined analysis
  30. GRB 060522: Swift-BAT Refined Analysis
  31. GRB 060522: REM NIR observations
  32. GRB 060522: TNG optical observations
  33. GRB 060522: Swift detection of a burst with possible optical afterglow
  34. GRB 060512: reanalysis of optical spectra
  35. GRB 060515: NIR observation
  36. GRB 060210: Jet Break in the XRT light curve
  37. GRB 060516: Refined analysis of the Swift-BAT burst
  38. GRB 060512: TNG optical spectroscopy
  39. GRB 060516: Swift detection of a burst
  40. GRB060515: P200 NIR Observations
  41. GRB 060505 BAT refined analysis
  42. GRB 060515 BAT refined analysis
  43. GRB 060512: TAROT optical observation
  44. GRB 060515: Swift/XRT Team refined analysis
  45. GRB 060515: Swift/UVOT Upper Limits
  46. GRB 060515: Swift/XRT position
  47. GRB 060515: Super-LOTIS Observations
  48. GRB060515: Swift/UVOT initial observation
  49. GRB 060515: TAROT optical observation
  50. GRB 060515: ROTSE-III Optical Limits
  51. GRB 060515: Swift detection of a burst
  52. VLT optical spectroscopy of GRB 060512
  53. Swift/UVOT observations of GRB060512.
  54. GRB 060512: Subaru NIR observation
  55. GRB060512: Swift XRT Team refined analysis
  56. GRB 060512: 1.54m Kuiper Observations
  57. GRB 060512: Detection of NIR afterglow
  58. GRB 060512: P60 Observations
  59. GRB 060512: Swift-BAT Refined Analysis
  60. GRB 060505 - OT candidate + galaxy spectrum
  61. GRB 060512: optical decay
  62. GRB 060512: REM NIR observations
  63. GRB060512 - SDSS Pre-Burst Observations
  64. GRB060512 Name Correction: LT Afterglow detection
  65. GRB060512: Liverpool Telescope Afterglow detection
  66. GRB 060512: Swift detection of a burst with an optical afterglow
  67. GRB 060510A: Swift/UVOT Detection of an Optical Afterglow
  68. GRB 060505: X-ray afterglow - Correction -
  69. GRB 060505: X-ray afterglow
  70. Konus-Wind observation of GRB 060510A
  71. GRB060418: optical observations
  72. GRB 060428a, SMARTS optical/IR afterglow detection
  73. GRB060510B: Swift XRT refined analysis
  74. GRB 060510B: Swift/UVOT Upper Limits
  75. GRB 060510A: Refined analysis of the Swift-BAT burst
  76. GRB 060510B: Swift-BAT Refined Analysis
  77. GRB060510A: XRT refined analysis
  78. GRB060510 - SDSS Pre-Burst Observations
  79. GRB 060510b: Redshift
  80. GRB060510B : Faulkes North Telescope detection
  81. GRB 060510B : Planned XMM-Newton observation
  82. GRB 060510b: Gemini NIR observations
  83. GRB 060510B: Super-LOTIS Observations
  84. GRB 060510b: NIR observations
  85. GRB 060510B: Coordinate correction
  86. GRB 060510B: MDM Observations and candidate OT
  87. GRB 060510B: Swift detection of a burst
  88. GRB 060510: Swift detection of a burst with optical transient
  89. GRB060507: optical afterglow detection
  90. GRB060502B: improvement in the XRT afterglow position
  91. GRB 060507: BART limit
  92. GRB 060507: Final Refined analysis of the Swift-BAT burst
  93. GRB 060507: Swift-BAT Refined Analysis
  94. GRB 060505: PROMPT Observations
  95. GRB 060507: Swift/UVOT Upper Limits
  96. GRB 060507: Swift XRT Team Refined Analysis
  97. GRB 060507: MDM Optical Upper Limit
  98. GRB060507: Swift XRT position
  99. GRB 060507: Swift detection of a burst
  100. GRB 060429: Suzaku WAM observation

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