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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 060218: Likely an underluminous GRB
  2. GRB060218: Optical Spectroscopy of GRB-SN
  3. GRB060218: VLT spectroscopy
  4. GRB 060218: Optical Observations at Xinglong Obs.
  5. GRB 060219: SDSS galaxy inside XRT error circle
  6. GRB060218: UV Detection and Light Curves
  7. GRB060219: SARA Observations
  8. GRB 060219: Swift/UVOT Upper Limits
  9. GRB 060219: Swift-XRT Team refined analysis
  10. GRB 051221B: Swift-XRT Team Refined Analysis
  11. GRB 060219: Partial refined analysis of the Swift-BAT burst
  12. GRB060218: Radio Afterglow Discovery
  13. GRB 060219: Swift-XRT position typo correction
  14. GRB 060218: MDM Redshift
  15. GRB 060219: Swift-XRT position
  16. GRB 060218: optical/nIR observations at La Palma
  17. GRB060219: SDSS pre-burst observations
  18. GRB 060219: Swift-BAT detection of a weak burst
  19. Oddball GRB 060218, transient or GRB?
  20. GRB060218: Swift/XRT Team preliminary analysis of the possible burst
  21. Brightening of the Optical Counterpart of the Possible GRB 060218
  22. GRB 060218: MDM Observations
  23. GRB 060218: Pre-burst detection of a possible host galaxy
  24. GRB 060218A: ROTSE-III Possible Optical Flare
  25. GRB060218: Swift/XRT refined position of a possible burst
  26. Preliminary refined analysis of the Swift-BAT trigger 191157
  27. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  28. GRB 060211B: Swift/UVOT Upper Limits
  29. GRB060218 : SDSS pre-burst observations
  30. Subject: GRB 060218: Swift XRT Position
  31. GRB 060218: Swift-BAT detection of a possible burst
  32. GRB 060213: optical afterglow not confirmed
  33. Swift UVOT observations of GRB060213
  34. GRB 060211B: Skynet Observations
  35. GRB 060213: optical afterglow candidate
  36. GRB060213: Swift XRT observations and possible afterglow candidate
  37. GRB 060213: pseudo-z = 3.5 +/- 0.35 from spectral parameters
  38. GRB 060206: Confirmation of Rapid Fading at Optical Wavelengths
  39. GRB060213: MASTER final result
  40. GRB 060211b: WIRO NIR Observations
  41. GRB060213:_MASTER_optical_observation
  42. GRB060206: Swift XRT observations of an unbroken powerlaw decay
  43. Konus-Wind observation of bright hard GRB 060213
  44. GRB 060213: IPN localization
  45. GRB 060210: Radio Observations
  46. GRB 060211a: WIRO NIR Observations
  47. GRB060211B: REM optical and NIR observations
  48. GRB 060211B: BAT detects no additional burst emission beyond T + 122 sec
  49. GRB 060211A: Further refined analysis of the Swift burst
  50. GRB060121: optical observations
  51. GRB060110: optical observations
  52. GRB060105: optical observations
  53. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  54. GRB 060211b: P60 Observations
  55. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  56. GRB 060206: SOAR Detections
  57. GRB 050826: Optical Afterglow and Host Galaxy
  58. GRB 060210: Further refined analysis of the Swift-BAT burst
  59. GRB 060211B: Swift/BAT refined analysis
  60. GRB060210: Swift/UVOT Upper Limits
  61. GRB 060211B: Swift-XRT Team refined analysis
  62. GRB060211b: optical observation
  63. GRB060211B: Swift/XRT position
  64. GRB 060210: Optical Observations
  65. GRB060211.7: MASTER_optical_observation under the snow
  66. GRB 060211A: Swift XRT Team Refined Analysis
  67. GRB 060211B: Swift-BAT detection of a burst
  68. GRB060211: Faulkes North observation
  69. GRB 060211: ROTSE-III Optical Limits
  70. GRB 060211: Swift detection of a long burst
  71. GRB 060210: Refined analysis of the Swift-BAT burst
  72. GRB060210: Swift XRT Refined Analysis
  73. GRB060206, optical observations
  74. GRB 060210 : Xinglong and Lulin optical limit
  75. GRB060210: Optical Observations
  76. GRB060210: Gemini absorption spectroscopy
  77. GRB060210: Early Optical Observations
  78. GRB 060210: optical evolution
  79. GRB060210:Faulkes Telescope North Afterglow Confirmation
  80. GRB 060210: candidate afterglow
  81. GRB 060210: Swift detection of a burst
  82. GRB060210: Optical afterglow
  83. GRB 060206: Swift/UVOT Observations
  84. Swift-BAT trigger 180931 is not a GRB
  85. GRB060209: RTT150 optical observations
  86. GRB 060209 : TAROT optical observation
  87. GRB060209A: MASTER optical observation
  88. GRB 060209(?): Swift-BAT detection of a possible burst
  89. GRB 060206: near-infrared observations (JK' imaging)
  90. GRB 060206: WSRT Radio Observations
  91. GRB 060203: Swift/UVOT upper limits
  92. GRB 060206: TTT Observations
  93. GRB 060206: More PROMPT Detections
  94. GRB 060121 : WIDGET Pre-trigger limit
  95. GRB 060206: Tenagra II Observations
  96. GRB 060206: PROMPT Detections
  97. Retraction of orphan GRB afterglow candidate
  98. GRB060204a: Swift XRT Source is not GRB Afterglow
  99. GRB 060206: optical observations at Asiago
  100. Orphan GRB Afterglow candidate

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