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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: RTT150 optical observations
  2. GRB060526: Further Swift-UVOT Observations
  3. GRB060526, optical observations
  4. GRB 060526: Magellan Redshift
  5. GRB 060526 Lulin optical observation
  6. GRB 060526: Swift/XRT Team refined analysis
  7. GRB 060526: TNG optical observations
  8. GRB 060526: ROTSE-III Observations of Optical Counterpart
  9. GRB 060526: Watcher Observations
  10. GRB060526 - SDSS Pre-burst Observations
  11. GRB 060526: Continued emission for the Swift burst
  12. GRB 060526: Swift detection of a burst with x-ray and optical afterglow
  13. GRB060505: VLT observations of the optical afterglow
  14. GRB 060413 : WIDGET simultaneous optical observations
  15. GRB 060522: Swift/UVOT Observations: Correction
  16. GRB 060522: Swift/UVOT Observations of the Optical Afterglow
  17. XMM-Newton observation of GRB060510b
  18. GRB060512: Late-Time P200 Observations
  19. GRB060522: z = 5.11 Keck-LRIS Redshift
  20. GRB 060522: Swift/XRT Team refined analysis
  21. GRB 060522: Swift-BAT Refined Analysis
  22. GRB 060522: REM NIR observations
  23. GRB 060522: TNG optical observations
  24. GRB 060522: Swift detection of a burst with possible optical afterglow
  25. GRB 060512: reanalysis of optical spectra
  26. GRB 060515: NIR observation
  27. GRB 060210: Jet Break in the XRT light curve
  28. GRB 060516: Refined analysis of the Swift-BAT burst
  29. GRB 060512: TNG optical spectroscopy
  30. GRB 060516: Swift detection of a burst
  31. GRB060515: P200 NIR Observations
  32. GRB 060505 BAT refined analysis
  33. GRB 060515 BAT refined analysis
  34. GRB 060512: TAROT optical observation
  35. GRB 060515: Swift/XRT Team refined analysis
  36. GRB 060515: Swift/UVOT Upper Limits
  37. GRB 060515: Swift/XRT position
  38. GRB 060515: Super-LOTIS Observations
  39. GRB060515: Swift/UVOT initial observation
  40. GRB 060515: TAROT optical observation
  41. GRB 060515: ROTSE-III Optical Limits
  42. GRB 060515: Swift detection of a burst
  43. VLT optical spectroscopy of GRB 060512
  44. Swift/UVOT observations of GRB060512.
  45. GRB 060512: Subaru NIR observation
  46. GRB060512: Swift XRT Team refined analysis
  47. GRB 060512: 1.54m Kuiper Observations
  48. GRB 060512: Detection of NIR afterglow
  49. GRB 060512: P60 Observations
  50. GRB 060512: Swift-BAT Refined Analysis
  51. GRB 060505 - OT candidate + galaxy spectrum
  52. GRB 060512: optical decay
  53. GRB 060512: REM NIR observations
  54. GRB060512 - SDSS Pre-Burst Observations
  55. GRB060512 Name Correction: LT Afterglow detection
  56. GRB060512: Liverpool Telescope Afterglow detection
  57. GRB 060512: Swift detection of a burst with an optical afterglow
  58. GRB 060510A: Swift/UVOT Detection of an Optical Afterglow
  59. GRB 060505: X-ray afterglow - Correction -
  60. GRB 060505: X-ray afterglow
  61. Konus-Wind observation of GRB 060510A
  62. GRB060418: optical observations
  63. GRB 060428a, SMARTS optical/IR afterglow detection
  64. GRB060510B: Swift XRT refined analysis
  65. GRB 060510B: Swift/UVOT Upper Limits
  66. GRB 060510A: Refined analysis of the Swift-BAT burst
  67. GRB 060510B: Swift-BAT Refined Analysis
  68. GRB060510A: XRT refined analysis
  69. GRB060510 - SDSS Pre-Burst Observations
  70. GRB 060510b: Redshift
  71. GRB060510B : Faulkes North Telescope detection
  72. GRB 060510B : Planned XMM-Newton observation
  73. GRB 060510b: Gemini NIR observations
  74. GRB 060510B: Super-LOTIS Observations
  75. GRB 060510b: NIR observations
  76. GRB 060510B: Coordinate correction
  77. GRB 060510B: MDM Observations and candidate OT
  78. GRB 060510B: Swift detection of a burst
  79. GRB 060510: Swift detection of a burst with optical transient
  80. GRB060507: optical afterglow detection
  81. GRB060502B: improvement in the XRT afterglow position
  82. GRB 060507: BART limit
  83. GRB 060507: Final Refined analysis of the Swift-BAT burst
  84. GRB 060507: Swift-BAT Refined Analysis
  85. GRB 060505: PROMPT Observations
  86. GRB 060507: Swift/UVOT Upper Limits
  87. GRB 060507: Swift XRT Team Refined Analysis
  88. GRB 060507: MDM Optical Upper Limit
  89. GRB060507: Swift XRT position
  90. GRB 060507: Swift detection of a burst
  91. GRB 060429: Suzaku WAM observation
  92. GRB060505: Swift/UVOT Observations
  93. GRB 060505: Swift XRT Team Refined Analysis
  94. GRB060425: new MASTER survey method
  95. GRB 060306: Further Analysis of SOAR and APO NIR Observations
  96. GRB 060505: Swift XRT afterglow canditate position
  97. GRB 060502b: Second epoch Gemini observations
  98. GRB 060505: Swift-BAT detection of a weak burst
  99. GRB 060428B: spectroscopy
  100. GRB 060502B: optical observations

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