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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"

27394 results found.

  1. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  2. GRB060206: Swift-BAT detection of a burst
  3. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  4. GRB060204C: optical observation
  5. GRB 060204A: Swift XRT upper limit
  6. GRB 060204A: FRAM optical observations
  7. GRB060204B: Swift/UVOT refined analysis
  8. GRB 060204C: optical observations
  9. Swift XRT Observation of GRB 060204C
  10. GRB 060204B: Swift-BAT refined analysis
  11. GRB 060204B: ART early limit
  12. GRB 060204b: Keck/LRIS Afterglow Confirmation
  13. GRB 060204C: Liverpool Telescopes optical limit
  14. GRB 060204C: Swift-BAT detection of a burst
  15. GRB 060204A: further INTEGRAL results
  16. GRB060204B, optical observation
  17. GRB060204B - SDSS pre-burst observations
  18. GRB 060203: Swift-BAT refined analysis
  19. GRB 060204B: Swift detection of a burst
  20. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  21. GRB 060203: RTT150 optical observations
  22. GRB 060203: IR Counterpart
  23. Possible GRB 060203: optical observations at Asiago
  24. GRB 060202: PROMPT Observations
  25. GRB 060202: GETS observation
  26. GRB 060202: Gemini-N J, H, K_s observations
  27. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  28. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  29. GRB 060202: Refined analysis of the Swift-BAT burst
  30. GRB060202, optical observation
  31. GRB 060202: Swift/UVOT upper limits
  32. GRB 060121: Gemini Late-time Observations
  33. GRB 060130: PROMPT Observations
  34. GRB060130: Further R-band imaging
  35. GRB 060130: Swift/XRT observation
  36. GRB 060123: Gemini spectroscopy of the putative host galaxy
  37. GRB060130: Optical imaging
  38. GRB060130: REM infrared observations
  39. GRB 060130, SMARTS optical observations
  40. GRB 060130: FRAM optical observations
  41. GRB 060130: further INTEGRAL IBIS results
  42. GRB 060121: Confirmation of NIR Afterglow
  43. GRB 060123: Swift refined analysis of an unusual GRB
  44. GRB060124, BVRcIc field calibration
  45. GRB 060121: Probable Detection of NIR Afterglow
  46. GRB 060116 HST observations
  47. GRB 060124: HETE detection and spectrum of the main peak
  48. GRB060124: detailed XRT analysis
  49. GRB 060124: ART optical limits during the burst
  50. GRB060123: Optical and IR Imaging
  51. GRB 060123: P200 Observations
  52. GRB 060124: XRT refined analysis
  53. GRB 060124: R band Observations
  54. GRB 060124 : Optical observation at Xinglong and Kiso
  55. GRB060124: optical observations at Asiago
  56. GRB060123: SDSS pre-burst observations
  57. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  58. GRB 060121: OHP optical limits
  59. GRB 060124: TAROT optical limits
  60. GRB060124, optical observation
  61. GRB 060124: Optical Observations at Tautenburg
  62. GRB 060117: Suzaku WAM observation of the prompt emission
  63. GRB 060111B: Suzaku WAM observation of the prompt emission
  64. GRB 060124: Swift-BAT detection of a burst
  65. GRB 060121: Liverpool Telescopes optical limits
  66. GRB 060121: Swift XRT refined analysis
  67. Konus-Wind observation of GRB 060121
  68. GRB 060121: candidate optical counterpart
  69. GRB 060121: Infrared Observations
  70. GRB 060121: optical observations
  71. GRB 060121: Optical imaging
  72. GRB060121 - SDSS pre-burst observations
  73. HETE Alert 4006: MASTER promt optical limit
  74. GRB060117 - ATCA 3/6cm radio limits - correction
  75. GRB060117 - ATCA 3/6cm radio limits
  76. GRB 060116: photometric redshift - the farthest GRB?
  77. Konus-Wind observation of GRB 060117
  78. GRB 060116: UKIRT IR Observations
  79. GRB 060117: Refined analysis of the Swift-BAT burst
  80. GRB 060117: FRAM optical afterglow candidate
  81. GRB 060117: nearby galaxy
  82. GRB 060116: VLT optical observations
  83. GRB 060116: Refined analysis of the Swift-BAT burst
  84. GRB 060116: XRT refined analysis
  85. GRB 060116: IR Candidate Afterglow
  86. GRB 060116: Swift/UVOT upper limits
  87. GRB060115: REM observations
  88. GRB 060110: XRT position and analysis
  89. GRB 060116 : Lulin optical limit
  90. GRB060116: Faulkes North observation
  91. GRB 060116: Swift-BAT detection of a burst
  92. GRB 060115: Refined analysis of the Swift-BAT burst
  93. GRB 060115: Swift/UVOT upper limits
  94. GRB 060114: REM observations
  95. GRB 060115: Swift XRT refined analysis
  96. GRB 060114: Swift/UVOT Observations
  97. GRB060115, optical observation
  98. GRB 060115: MITSuME optical afterglow candidate
  99. GRB 060115: Swift detection of a burst
  100. GRB060114, optical observation

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