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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 060223: Swift/UVOT Confirmation of Optical Afterglow
  2. GRB 060223: Swift detection of a burst
  3. Spectral properties of GRB060218/SN2006aj
  4. GRB 060219: Swift-BAT refined analysis
  5. GRB 060218: rebrightening
  6. GRB 060218: emergence of the underlying SN spectrum
  7. GRB 060218: Decline in r-band flux
  8. GRB 060218: spectroscopic observations
  9. GRB 060218: Further refined analysis of the Swift-BAT burst
  10. GRB 060218: Likely an underluminous GRB
  11. GRB060218: Optical Spectroscopy of GRB-SN
  12. GRB060218: VLT spectroscopy
  13. GRB 060218: Optical Observations at Xinglong Obs.
  14. GRB 060219: SDSS galaxy inside XRT error circle
  15. GRB060218: UV Detection and Light Curves
  16. GRB060219: SARA Observations
  17. GRB 060219: Swift/UVOT Upper Limits
  18. GRB 060219: Swift-XRT Team refined analysis
  19. GRB 051221B: Swift-XRT Team Refined Analysis
  20. GRB 060219: Partial refined analysis of the Swift-BAT burst
  21. GRB060218: Radio Afterglow Discovery
  22. GRB 060219: Swift-XRT position typo correction
  23. GRB 060218: MDM Redshift
  24. GRB 060219: Swift-XRT position
  25. GRB 060218: optical/nIR observations at La Palma
  26. GRB060219: SDSS pre-burst observations
  27. GRB 060219: Swift-BAT detection of a weak burst
  28. Oddball GRB 060218, transient or GRB?
  29. GRB060218: Swift/XRT Team preliminary analysis of the possible burst
  30. Brightening of the Optical Counterpart of the Possible GRB 060218
  31. GRB 060218: MDM Observations
  32. GRB 060218: Pre-burst detection of a possible host galaxy
  33. GRB 060218A: ROTSE-III Possible Optical Flare
  34. GRB060218: Swift/XRT refined position of a possible burst
  35. Preliminary refined analysis of the Swift-BAT trigger 191157
  36. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  37. GRB 060211B: Swift/UVOT Upper Limits
  38. GRB060218 : SDSS pre-burst observations
  39. GRB 060218: Swift XRT Position
  40. GRB 060218: Swift-BAT detection of a possible burst
  41. GRB 060213: optical afterglow not confirmed
  42. Swift UVOT observations of GRB060213
  43. GRB 060211B: Skynet Observations
  44. GRB 060213: optical afterglow candidate
  45. GRB060213: Swift XRT observations and possible afterglow candidate
  46. GRB 060213: pseudo-z = 3.5 +/- 0.35 from spectral parameters
  47. GRB 060206: Confirmation of Rapid Fading at Optical Wavelengths
  48. GRB060213: MASTER final result
  49. GRB 060211b: WIRO NIR Observations
  50. GRB060213:_MASTER_optical_observation
  51. GRB060206: Swift XRT observations of an unbroken powerlaw decay
  52. Konus-Wind observation of bright hard GRB 060213
  53. GRB 060213: IPN localization
  54. GRB 060210: Radio Observations
  55. GRB 060211a: WIRO NIR Observations
  56. GRB060211B: REM optical and NIR observations
  57. GRB 060211B: BAT detects no additional burst emission beyond T + 122 sec
  58. GRB 060211A: Further refined analysis of the Swift burst
  59. GRB060121: optical observations
  60. GRB060110: optical observations
  61. GRB060105: optical observations
  62. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  63. GRB 060211b: P60 Observations
  64. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  65. GRB 060206: SOAR Detections
  66. GRB 050826: Optical Afterglow and Host Galaxy
  67. GRB 060210: Further refined analysis of the Swift-BAT burst
  68. GRB 060211B: Swift/BAT refined analysis
  69. GRB060210: Swift/UVOT Upper Limits
  70. GRB 060211B: Swift-XRT Team refined analysis
  71. GRB060211b: optical observation
  72. GRB060211B: Swift/XRT position
  73. GRB 060210: Optical Observations
  74. GRB060211.7: MASTER_optical_observation under the snow
  75. GRB 060211A: Swift XRT Team Refined Analysis
  76. GRB 060211B: Swift-BAT detection of a burst
  77. GRB060211: Faulkes North observation
  78. GRB 060211: ROTSE-III Optical Limits
  79. GRB 060211: Swift detection of a long burst
  80. GRB 060210: Refined analysis of the Swift-BAT burst
  81. GRB060210: Swift XRT Refined Analysis
  82. GRB060206, optical observations
  83. GRB 060210 : Xinglong and Lulin optical limit
  84. GRB060210: Optical Observations
  85. GRB060210: Gemini absorption spectroscopy
  86. GRB060210: Early Optical Observations
  87. GRB 060210: optical evolution
  88. GRB060210:Faulkes Telescope North Afterglow Confirmation
  89. GRB 060210: candidate afterglow
  90. GRB 060210: Swift detection of a burst
  91. GRB060210: Optical afterglow
  92. GRB 060206: Swift/UVOT Observations
  93. Swift-BAT trigger 180931 is not a GRB
  94. GRB060209: RTT150 optical observations
  95. GRB 060209 : TAROT optical observation
  96. GRB060209A: MASTER optical observation
  97. GRB 060209(?): Swift-BAT detection of a possible burst
  98. GRB 060206: near-infrared observations (JK' imaging)
  99. GRB 060206: WSRT Radio Observations
  100. GRB 060203: Swift/UVOT upper limits

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