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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. GRB060210:Faulkes Telescope North Afterglow Confirmation
  2. GRB 060210: candidate afterglow
  3. GRB 060210: Swift detection of a burst
  4. GRB060210: Optical afterglow
  5. GRB 060206: Swift/UVOT Observations
  6. Swift-BAT trigger 180931 is not a GRB
  7. GRB060209: RTT150 optical observations
  8. GRB 060209 : TAROT optical observation
  9. GRB060209A: MASTER optical observation
  10. GRB 060209(?): Swift-BAT detection of a possible burst
  11. GRB 060206: near-infrared observations (JK' imaging)
  12. GRB 060206: WSRT Radio Observations
  13. GRB 060203: Swift/UVOT upper limits
  14. GRB 060206: TTT Observations
  15. GRB 060206: More PROMPT Detections
  16. GRB 060121 : WIDGET Pre-trigger limit
  17. GRB 060206: Tenagra II Observations
  18. GRB 060206: PROMPT Detections
  19. Retraction of orphan GRB afterglow candidate
  20. GRB060204a: Swift XRT Source is not GRB Afterglow
  21. GRB 060206: optical observations at Asiago
  22. Orphan GRB Afterglow candidate
  23. GRB 060204b: pseudo-z from spectral parameters of the prompt emission
  24. GRB 060206: Subaru/FOCAS optical spectroscopy
  25. GRB 060206: IR Detection of the Afterglow
  26. GRB 060206: Lick 3m Spectroscopy
  27. GRB 060204A: ROSAT Pointing
  28. GRB 060206: Super-LOTIS observations
  29. GRB060204A: Swift/UVOT observations
  30. GRB 060206: Swift-BAT refined analysis
  31. GRB 060206 : Lulin optical observations
  32. GRB060206: SDSS Pre-Burst Observations
  33. GRB060206: Swift XRT Refined Analysis
  34. GRB060206: Liverpool Telescope observation
  35. GRB 060206: Spectroscopic Redshift
  36. GRB060206: P60 Optical Observations
  37. GRB 060206: KAIT observations
  38. GRB060206: Swift XRT Position
  39. GRB060206: SARA Detection
  40. GRB 060206: RAPTOR observations of afterglow candidate variability.
  41. GRB 060206: High redshift burst
  42. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  43. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  44. GRB060206: Optical afterglow
  45. GRB060206: Swift-BAT detection of a burst
  46. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  47. GRB060203: WHT Z-band observations
  48. BAT GRB 060204C is probably not a GRB
  49. GRB060204C: optical observation
  50. GRB 060204B: BVRi-band detections of optical afterglow
  51. GRB 060204A: Swift XRT upper limit
  52. GRB 060204A: FRAM optical observations
  53. GRB060204B: Swift/UVOT refined analysis
  54. GRB 060204C: optical observations
  55. Swift XRT Observation of GRB 060204C
  56. GRB 060204B: Swift-BAT refined analysis
  57. GRB 060204B: ART early limit
  58. GRB060204B: Swift XRT Team Refined Analysis
  59. GRB 060204C: OSN limits
  60. GRB 060204b: Keck/LRIS Afterglow Confirmation
  61. GRB 060204C: BOOTES-IR optical limits
  62. GRB 060204C: Liverpool Telescopes optical limit
  63. GRB 060204C: ROTSE-III Optical Limits
  64. GRB 060204C: Swift-BAT detection of a burst
  65. GRB 060124: Radio Observations
  66. GRB060204B: Faulkes OT candidate
  67. GRB 060204B: ART optical limit
  68. GRB 060204A: further INTEGRAL results
  69. GRB060204B, optical observation
  70. GRB060204B - SDSS pre-burst observations
  71. GRB 060203: Swift-BAT refined analysis
  72. GRB 060204B: Swift detection of a burst
  73. GRB 060204: a long GRB detected by INTEGRAL
  74. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  75. GRB 060203: RTT150 optical observations
  76. GRB060203: Swift XRT Team Refined Analysis
  77. GRB060203 - Swift UVOT observation
  78. Swift-BAT trigger is GRB 060203
  79. GRB 060203: IR Counterpart
  80. GRB060203: Observations with SARA
  81. GRB 060203: P60 Confirmation of Optical Afterglow
  82. Possible GRB 060203: candidate optical counterpart
  83. Swift BAT Trigger 180151: Swift XRT source detection
  84. Possible GRB 060203: optical observations at Asiago
  85. GRB 060202: PROMPT Observations
  86. Swift-BAT trigger 180151 is unknown origin at this time
  87. GRB 060202: GETS observation
  88. GRB 060202: Gemini-N J, H, K_s observations
  89. GRB 060202 : Kiso B and R band limit
  90. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  91. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  92. GRB 060202: Refined analysis of the Swift-BAT burst
  93. GRB060202, optical observation
  94. GRB 060202: Swift/UVOT upper limits
  95. GRB 060202: Swift XRT Team Refined Analysis
  96. GRB 060202 : Lulin R and I band limit
  97. GRB060202: Faulkes North observation
  98. GRB 060202: Swift detection of a burst
  99. GRB 060121: Gemini Late-time Observations
  100. Erratum: SDSS pre-burst observations of GRB fields

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