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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 Lulin optical observation
  2. GRB 060526: Swift/XRT Team refined analysis
  3. GRB 060526: TNG optical observations
  4. GRB 060526: ROTSE-III Observations of Optical Counterpart
  5. GRB 060526: Watcher Observations
  6. GRB060526 - SDSS Pre-burst Observations
  7. GRB 060526: Continued emission for the Swift burst
  8. GRB 060526: Swift detection of a burst with x-ray and optical afterglow
  9. GRB060505: VLT observations of the optical afterglow
  10. GRB 060413 : WIDGET simultaneous optical observations
  11. GRB 060522: Swift/UVOT Observations: Correction
  12. GRB 060522: Swift/UVOT Observations of the Optical Afterglow
  13. XMM-Newton observation of GRB060510b
  14. GRB060512: Late-Time P200 Observations
  15. GRB060522: z = 5.11 Keck-LRIS Redshift
  16. GRB 060522: Swift/XRT Team refined analysis
  17. GRB 060522: Swift-BAT Refined Analysis
  18. GRB 060522: REM NIR observations
  19. GRB 060522: TNG optical observations
  20. GRB 060522: Swift detection of a burst with possible optical afterglow
  21. GRB 060512: reanalysis of optical spectra
  22. GRB 060515: NIR observation
  23. GRB 060210: Jet Break in the XRT light curve
  24. GRB 060516: Refined analysis of the Swift-BAT burst
  25. GRB 060512: TNG optical spectroscopy
  26. GRB 060516: Swift detection of a burst
  27. GRB060515: P200 NIR Observations
  28. GRB 060505 BAT refined analysis
  29. GRB 060515 BAT refined analysis
  30. GRB 060512: TAROT optical observation
  31. GRB 060515: Swift/XRT Team refined analysis
  32. GRB 060515: Swift/UVOT Upper Limits
  33. GRB 060515: Swift/XRT position
  34. GRB 060515: Super-LOTIS Observations
  35. GRB060515: Swift/UVOT initial observation
  36. GRB 060515: TAROT optical observation
  37. GRB 060515: ROTSE-III Optical Limits
  38. GRB 060515: Swift detection of a burst
  39. VLT optical spectroscopy of GRB 060512
  40. Swift/UVOT observations of GRB060512.
  41. GRB 060512: Subaru NIR observation
  42. GRB060512: Swift XRT Team refined analysis
  43. GRB 060512: 1.54m Kuiper Observations
  44. GRB 060512: Detection of NIR afterglow
  45. GRB 060512: P60 Observations
  46. GRB 060512: Swift-BAT Refined Analysis
  47. GRB 060505 - OT candidate + galaxy spectrum
  48. GRB 060512: optical decay
  49. GRB 060512: REM NIR observations
  50. GRB060512 - SDSS Pre-Burst Observations
  51. GRB060512 Name Correction: LT Afterglow detection
  52. GRB060512: Liverpool Telescope Afterglow detection
  53. GRB 060512: Swift detection of a burst with an optical afterglow
  54. GRB 060510A: Swift/UVOT Detection of an Optical Afterglow
  55. GRB 060505: X-ray afterglow - Correction -
  56. GRB 060505: X-ray afterglow
  57. Konus-Wind observation of GRB 060510A
  58. GRB060418: optical observations
  59. GRB 060428a, SMARTS optical/IR afterglow detection
  60. GRB060510B: Swift XRT refined analysis
  61. GRB 060510B: Swift/UVOT Upper Limits
  62. GRB 060510A: Refined analysis of the Swift-BAT burst
  63. GRB 060510B: Swift-BAT Refined Analysis
  64. GRB060510A: XRT refined analysis
  65. GRB060510 - SDSS Pre-Burst Observations
  66. GRB 060510b: Redshift
  67. GRB060510B : Faulkes North Telescope detection
  68. GRB 060510B : Planned XMM-Newton observation
  69. GRB 060510b: Gemini NIR observations
  70. GRB 060510B: Super-LOTIS Observations
  71. GRB 060510b: NIR observations
  72. GRB 060510B: Coordinate correction
  73. GRB 060510B: MDM Observations and candidate OT
  74. GRB 060510B: Swift detection of a burst
  75. GRB 060510: Swift detection of a burst with optical transient
  76. GRB060507: optical afterglow detection
  77. GRB060502B: improvement in the XRT afterglow position
  78. GRB 060507: BART limit
  79. GRB 060507: Final Refined analysis of the Swift-BAT burst
  80. GRB 060507: Swift-BAT Refined Analysis
  81. GRB 060505: PROMPT Observations
  82. GRB 060507: Swift/UVOT Upper Limits
  83. GRB 060507: Swift XRT Team Refined Analysis
  84. GRB 060507: MDM Optical Upper Limit
  85. GRB060507: Swift XRT position
  86. GRB 060507: Swift detection of a burst
  87. GRB 060429: Suzaku WAM observation
  88. GRB060505: Swift/UVOT Observations
  89. GRB 060505: Swift XRT Team Refined Analysis
  90. GRB060425: new MASTER survey method
  91. GRB 060306: Further Analysis of SOAR and APO NIR Observations
  92. GRB 060505: Swift XRT afterglow canditate position
  93. GRB 060502b: Second epoch Gemini observations
  94. GRB 060505: Swift-BAT detection of a weak burst
  95. GRB 060428B: spectroscopy
  96. GRB 060502B: optical observations
  97. GRB 060502B: AROMA refined photometric calibration
  98. GRB 060502B MDM Follow-up Observation
  99. GRB 060502b: Gemini imaging and spectroscopy
  100. GRB060502A, optical observation

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