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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 060223B: Swift detection of a bright burst
  2. GRB 060223: Swift-BAT refined analysis
  3. GRB 060218: rebrightening
  4. Correction to GCN 4816 on GRB060218
  5. GRB 060218/SN 2006aj: optical observations
  6. GRB060218: Optical brightening in V and R
  7. GRB 060223: Keck redshift
  8. GRB 060223: Swift/UVOT Confirmation of Optical Afterglow
  9. GRB 060223: Swift detection of a burst
  10. Spectral properties of GRB060218/SN2006aj
  11. GRB 060219: Swift-BAT refined analysis
  12. GRB 060218: rebrightening
  13. GRB 060218: emergence of the underlying SN spectrum
  14. GRB 060218: Decline in r-band flux
  15. GRB 060218: spectroscopic observations
  16. GRB 060218: Further refined analysis of the Swift-BAT burst
  17. GRB 060218: Likely an underluminous GRB
  18. GRB060218: Optical Spectroscopy of GRB-SN
  19. GRB060218: VLT spectroscopy
  20. GRB 060218: Optical Observations at Xinglong Obs.
  21. GRB 060219: SDSS galaxy inside XRT error circle
  22. GRB060218: UV Detection and Light Curves
  23. GRB060219: SARA Observations
  24. GRB 060219: Swift/UVOT Upper Limits
  25. GRB 060219: Swift-XRT Team refined analysis
  26. GRB 051221B: Swift-XRT Team Refined Analysis
  27. GRB 060219: Partial refined analysis of the Swift-BAT burst
  28. GRB060218: Radio Afterglow Discovery
  29. GRB 060219: Swift-XRT position typo correction
  30. GRB 060218: MDM Redshift
  31. GRB 060219: Swift-XRT position
  32. GRB 060218: optical/nIR observations at La Palma
  33. GRB060219: SDSS pre-burst observations
  34. GRB 060219: Swift-BAT detection of a weak burst
  35. Oddball GRB 060218, transient or GRB?
  36. GRB060218: Swift/XRT Team preliminary analysis of the possible burst
  37. Brightening of the Optical Counterpart of the Possible GRB 060218
  38. GRB 060218: MDM Observations
  39. GRB 060218: Pre-burst detection of a possible host galaxy
  40. GRB 060218A: ROTSE-III Possible Optical Flare
  41. GRB060218: Swift/XRT refined position of a possible burst
  42. Preliminary refined analysis of the Swift-BAT trigger 191157
  43. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  44. GRB 060211B: Swift/UVOT Upper Limits
  45. GRB060218 : SDSS pre-burst observations
  46. GRB 060218: Swift XRT Position
  47. GRB 060218: Swift-BAT detection of a possible burst
  48. GRB 060213: optical afterglow not confirmed
  49. Swift UVOT observations of GRB060213
  50. GRB 060211B: Skynet Observations
  51. GRB 060213: optical afterglow candidate
  52. GRB060213: Swift XRT observations and possible afterglow candidate
  53. GRB 060213: pseudo-z = 3.5 +/- 0.35 from spectral parameters
  54. GRB 060206: Confirmation of Rapid Fading at Optical Wavelengths
  55. GRB060213: MASTER final result
  56. GRB 060211b: WIRO NIR Observations
  57. GRB060213:_MASTER_optical_observation
  58. GRB060206: Swift XRT observations of an unbroken powerlaw decay
  59. Konus-Wind observation of bright hard GRB 060213
  60. GRB 060213: IPN localization
  61. GRB 060210: Radio Observations
  62. GRB 060211a: WIRO NIR Observations
  63. GRB060211B: REM optical and NIR observations
  64. GRB 060211B: BAT detects no additional burst emission beyond T + 122 sec
  65. GRB 060211A: Further refined analysis of the Swift burst
  66. GRB060121: optical observations
  67. GRB060110: optical observations
  68. GRB060105: optical observations
  69. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  70. GRB 060211b: P60 Observations
  71. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  72. GRB 060206: SOAR Detections
  73. GRB 050826: Optical Afterglow and Host Galaxy
  74. GRB 060210: Further refined analysis of the Swift-BAT burst
  75. GRB 060211B: Swift/BAT refined analysis
  76. GRB060210: Swift/UVOT Upper Limits
  77. GRB 060211B: Swift-XRT Team refined analysis
  78. GRB060211b: optical observation
  79. GRB060211B: Swift/XRT position
  80. GRB 060210: Optical Observations
  81. GRB060211.7: MASTER_optical_observation under the snow
  82. GRB 060211A: Swift XRT Team Refined Analysis
  83. GRB 060211B: Swift-BAT detection of a burst
  84. GRB060211: Faulkes North observation
  85. GRB 060211: ROTSE-III Optical Limits
  86. GRB 060211: Swift detection of a long burst
  87. GRB 060210: Refined analysis of the Swift-BAT burst
  88. GRB060210: Swift XRT Refined Analysis
  89. GRB060206, optical observations
  90. GRB 060210 : Xinglong and Lulin optical limit
  91. GRB060210: Optical Observations
  92. GRB060210: Gemini absorption spectroscopy
  93. GRB060210: Early Optical Observations
  94. GRB 060210: optical evolution
  95. GRB060210:Faulkes Telescope North Afterglow Confirmation
  96. GRB 060210: candidate afterglow
  97. GRB 060210: Swift detection of a burst
  98. GRB060210: Optical afterglow
  99. GRB 060206: Swift/UVOT Observations
  100. Swift-BAT trigger 180931 is not a GRB

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