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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 060512: REM NIR observations
  2. GRB060512 - SDSS Pre-Burst Observations
  3. GRB060512 Name Correction: LT Afterglow detection
  4. GRB060512: Liverpool Telescope Afterglow detection
  5. GRB 060512: Swift detection of a burst with an optical afterglow
  6. GRB 060510A: Swift/UVOT Detection of an Optical Afterglow
  7. GRB 060505: X-ray afterglow - Correction -
  8. GRB 060505: X-ray afterglow
  9. Konus-Wind observation of GRB 060510A
  10. GRB060418: optical observations
  11. GRB 060428a, SMARTS optical/IR afterglow detection
  12. GRB060510B: Swift XRT refined analysis
  13. GRB 060510B: Swift/UVOT Upper Limits
  14. GRB 060510A: Refined analysis of the Swift-BAT burst
  15. GRB 060510B: Swift-BAT Refined Analysis
  16. GRB060510A: XRT refined analysis
  17. GRB060510 - SDSS Pre-Burst Observations
  18. GRB 060510b: Redshift
  19. GRB060510B : Faulkes North Telescope detection
  20. GRB 060510B : Planned XMM-Newton observation
  21. GRB 060510b: Gemini NIR observations
  22. GRB 060510B: Super-LOTIS Observations
  23. GRB 060510b: NIR observations
  24. GRB 060510B: Coordinate correction
  25. GRB 060510B: MDM Observations and candidate OT
  26. GRB 060510B: Swift detection of a burst
  27. GRB 060510: Swift detection of a burst with optical transient
  28. GRB060507: optical afterglow detection
  29. GRB060502B: improvement in the XRT afterglow position
  30. GRB 060507: BART limit
  31. GRB 060507: Final Refined analysis of the Swift-BAT burst
  32. GRB 060507: Swift-BAT Refined Analysis
  33. GRB 060505: PROMPT Observations
  34. GRB 060507: Swift/UVOT Upper Limits
  35. GRB 060507: Swift XRT Team Refined Analysis
  36. GRB 060507: MDM Optical Upper Limit
  37. GRB060507: Swift XRT position
  38. GRB 060507: Swift detection of a burst
  39. GRB 060429: Suzaku WAM observation
  40. GRB060505: Swift/UVOT Observations
  41. GRB 060505: Swift XRT Team Refined Analysis
  42. GRB060425: new MASTER survey method
  43. GRB 060306: Further Analysis of SOAR and APO NIR Observations
  44. GRB 060505: Swift XRT afterglow canditate position
  45. GRB 060502b: Second epoch Gemini observations
  46. GRB 060505: Swift-BAT detection of a weak burst
  47. GRB 060428B: spectroscopy
  48. GRB 060502B: optical observations
  49. GRB 060502B: AROMA refined photometric calibration
  50. GRB 060502B MDM Follow-up Observation
  51. GRB 060502b: Gemini imaging and spectroscopy
  52. GRB060502A, optical observation
  53. GRB 060502B: Swift/UVOT upper limits
  54. GRB 060502A: Swift/UVOT source detection
  55. GRB 060429: Refined IPN error box and Konus-Wind spectrum
  56. GRB 060502B: MDM Optical Observation
  57. GRB 060502B: AROMA optical observations
  58. GRB 060502B: Refined analysis of the Swift-BAT short burst
  59. GRB060502B: Swift XRT Team refined analysis
  60. Short GRB 060502B: Tautenburg Observation
  61. GRB 060427B Milagro GeV/TeV Observations
  62. GRB 060502A: TTT Observations
  63. GRB060502B: correction to XRT position
  64. GRB 060501: P60 Observations and Candidate Retraction
  65. GRB 060502B: Xinglong optical observation
  66. GRB 060502B: MASTER optical observations
  67. GRB 060502B: Swift detection of a short burst
  68. GRB060502: Swift-XRT refined analysis
  69. GRB 060502: Swift-BAT refined analysis
  70. GRB060502: Gemini spectroscopy
  71. GRB 060502: APO Spectroscopic Observations
  72. GRB060501: Swift UVOT followup observations
  73. GRB060502: Super-LOTIS Observations
  74. GRB 060502: P60 Afterglow Confirmation
  75. GRB 060502: Swift detection of a burst with an optical counterpart
  76. GRB 060501: MDM Observations
  77. GRB060501: Super-LOTIS observations
  78. GRB060501: P60 imaging and afterglow candidate
  79. GRB 060501: Refined analysis of the Swift-BAT burst
  80. GRB060501: Swift XRT position
  81. GRB 060501: ROTSE-III Optical Limits
  82. GRB 060501: Swift detection of a burst
  83. IPN triangulation of GRB060429 (short/hard)
  84. Konus-Wind observation of GRB 060427B
  85. GRB060428B - SDSS Pre-Burst Observations
  86. GRB060428B: optical observation
  87. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  88. GRB 060428B: MDM Observations
  89. GRB 060428A: PROMPT Observations
  90. GRB 060427B: MASTER optical observations
  91. GRB060428B: Swift XRT Team refined analysis
  92. GRB 060427B: IPN localization of a short hard burst
  93. GRB 060428B: Refined analysis of the Swift-BAT burst
  94. GRB 060428B: Xinglong I-band limit
  95. GRB 060428B: KAIT observations
  96. GRB060425:MASTER optical limit
  97. GRB 051117A: Bright host galaxy not confirmed
  98. GRB060428A: Swift/UVOT observations.
  99. GRB060428B, optical observation
  100. GRB 060428A: Refined analysis of the Swift-BAT burst

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