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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 060211A: Further refined analysis of the Swift burst
  2. GRB060121: optical observations
  3. GRB060110: optical observations
  4. GRB060105: optical observations
  5. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  6. GRB 060211b: P60 Observations
  7. GRB 060211A: Partial refined analysis on the Swift-BAT burst
  8. GRB 060206: SOAR Detections
  9. GRB 050826: Optical Afterglow and Host Galaxy
  10. GRB 060210: Further refined analysis of the Swift-BAT burst
  11. GRB 060211B: Swift/BAT refined analysis
  12. GRB060210: Swift/UVOT Upper Limits
  13. GRB 060211B: Swift-XRT Team refined analysis
  14. GRB060211b: optical observation
  15. GRB060211B: Swift/XRT position
  16. GRB 060210: Optical Observations
  17. GRB060211.7: MASTER_optical_observation under the snow
  18. GRB 060211A: Swift XRT Team Refined Analysis
  19. GRB 060211B: Swift-BAT detection of a burst
  20. GRB060211: Faulkes North observation
  21. GRB 060211: ROTSE-III Optical Limits
  22. GRB 060211: Swift detection of a long burst
  23. GRB 060210: Refined analysis of the Swift-BAT burst
  24. GRB060210: Swift XRT Refined Analysis
  25. GRB060206, optical observations
  26. GRB 060210 : Xinglong and Lulin optical limit
  27. GRB060210: Optical Observations
  28. GRB060210: Gemini absorption spectroscopy
  29. GRB060210: Early Optical Observations
  30. GRB 060210: optical evolution
  31. GRB060210:Faulkes Telescope North Afterglow Confirmation
  32. GRB 060210: candidate afterglow
  33. GRB 060210: Swift detection of a burst
  34. GRB060210: Optical afterglow
  35. GRB 060206: Swift/UVOT Observations
  36. Swift-BAT trigger 180931 is not a GRB
  37. GRB060209: RTT150 optical observations
  38. GRB 060209 : TAROT optical observation
  39. GRB060209A: MASTER optical observation
  40. GRB 060209(?): Swift-BAT detection of a possible burst
  41. GRB 060206: near-infrared observations (JK' imaging)
  42. GRB 060206: WSRT Radio Observations
  43. GRB 060203: Swift/UVOT upper limits
  44. GRB 060206: TTT Observations
  45. GRB 060206: More PROMPT Detections
  46. GRB 060121 : WIDGET Pre-trigger limit
  47. GRB 060206: Tenagra II Observations
  48. GRB 060206: PROMPT Detections
  49. Retraction of orphan GRB afterglow candidate
  50. GRB060204a: Swift XRT Source is not GRB Afterglow
  51. GRB 060206: optical observations at Asiago
  52. Orphan GRB Afterglow candidate
  53. GRB 060204b: pseudo-z from spectral parameters of the prompt emission
  54. GRB 060206: Subaru/FOCAS optical spectroscopy
  55. GRB 060206: IR Detection of the Afterglow
  56. GRB 060206: Lick 3m Spectroscopy
  57. GRB 060204A: ROSAT Pointing
  58. GRB 060206: Super-LOTIS observations
  59. GRB060204A: Swift/UVOT observations
  60. GRB 060206: Swift-BAT refined analysis
  61. GRB 060206 : Lulin optical observations
  62. GRB060206: SDSS Pre-Burst Observations
  63. GRB060206: Swift XRT Refined Analysis
  64. GRB060206: Liverpool Telescope observation
  65. GRB 060206: Spectroscopic Redshift
  66. GRB060206: P60 Optical Observations
  67. GRB 060206: KAIT observations
  68. GRB060206: Swift XRT Position
  69. GRB060206: SARA Detection
  70. GRB 060206: RAPTOR observations of afterglow candidate variability.
  71. GRB 060206: High redshift burst
  72. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  73. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  74. GRB060206: Optical afterglow
  75. GRB060206: Swift-BAT detection of a burst
  76. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  77. GRB060203: WHT Z-band observations
  78. BAT GRB 060204C is probably not a GRB
  79. GRB060204C: optical observation
  80. GRB 060204B: BVRi-band detections of optical afterglow
  81. GRB 060204A: Swift XRT upper limit
  82. GRB 060204A: FRAM optical observations
  83. GRB060204B: Swift/UVOT refined analysis
  84. GRB 060204C: optical observations
  85. Swift XRT Observation of GRB 060204C
  86. GRB 060204B: Swift-BAT refined analysis
  87. GRB 060204B: ART early limit
  88. GRB060204B: Swift XRT Team Refined Analysis
  89. GRB 060204C: OSN limits
  90. GRB 060204b: Keck/LRIS Afterglow Confirmation
  91. GRB 060204C: BOOTES-IR optical limits
  92. GRB 060204C: Liverpool Telescopes optical limit
  93. GRB 060204C: ROTSE-III Optical Limits
  94. GRB 060204C: Swift-BAT detection of a burst
  95. GRB 060124: Radio Observations
  96. GRB060204B: Faulkes OT candidate
  97. GRB 060204B: ART optical limit
  98. GRB 060204A: further INTEGRAL results
  99. GRB060204B, optical observation
  100. GRB060204B - SDSS pre-burst observations

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Download all Circulars as a .tar.gz archive (updated once a day):
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