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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"

24992 results found.

  1. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  2. GRB060204C: optical observation
  3. GRB 060204A: Swift XRT upper limit
  4. GRB 060204A: FRAM optical observations
  5. GRB060204B: Swift/UVOT refined analysis
  6. GRB 060204C: optical observations
  7. Swift XRT Observation of GRB 060204C
  8. GRB 060204B: Swift-BAT refined analysis
  9. GRB 060204B: ART early limit
  10. GRB 060204b: Keck/LRIS Afterglow Confirmation
  11. GRB 060204C: Liverpool Telescopes optical limit
  12. GRB 060204C: Swift-BAT detection of a burst
  13. GRB 060204A: further INTEGRAL results
  14. GRB060204B, optical observation
  15. GRB060204B - SDSS pre-burst observations
  16. GRB 060203: Swift-BAT refined analysis
  17. GRB 060204B: Swift detection of a burst
  18. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  19. GRB 060203: RTT150 optical observations
  20. GRB 060203: IR Counterpart
  21. Possible GRB 060203: optical observations at Asiago
  22. GRB 060202: PROMPT Observations
  23. GRB 060202: GETS observation
  24. GRB 060202: Gemini-N J, H, K_s observations
  25. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  26. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  27. GRB 060202: Refined analysis of the Swift-BAT burst
  28. GRB060202, optical observation
  29. GRB 060202: Swift/UVOT upper limits
  30. GRB 060121: Gemini Late-time Observations
  31. GRB 060130: PROMPT Observations
  32. GRB060130: Further R-band imaging
  33. GRB 060130: Swift/XRT observation
  34. GRB 060123: Gemini spectroscopy of the putative host galaxy
  35. GRB060130: Optical imaging
  36. GRB060130: REM infrared observations
  37. GRB 060130, SMARTS optical observations
  38. GRB 060130: FRAM optical observations
  39. GRB 060130: further INTEGRAL IBIS results
  40. GRB 060121: Confirmation of NIR Afterglow
  41. GRB 060123: Swift refined analysis of an unusual GRB
  42. GRB060124, BVRcIc field calibration
  43. GRB 060121: Probable Detection of NIR Afterglow
  44. GRB 060116 HST observations
  45. GRB 060124: HETE detection and spectrum of the main peak
  46. GRB060124: detailed XRT analysis
  47. GRB 060124: ART optical limits during the burst
  48. GRB060123: Optical and IR Imaging
  49. GRB 060123: P200 Observations
  50. GRB 060124: XRT refined analysis
  51. GRB 060124: R band Observations
  52. GRB 060124 : Optical observation at Xinglong and Kiso
  53. GRB060124: optical observations at Asiago
  54. GRB060123: SDSS pre-burst observations
  55. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  56. GRB 060121: OHP optical limits
  57. GRB 060124: TAROT optical limits
  58. GRB060124, optical observation
  59. GRB 060124: Optical Observations at Tautenburg
  60. GRB 060117: Suzaku WAM observation of the prompt emission
  61. GRB 060111B: Suzaku WAM observation of the prompt emission
  62. GRB 060124: Swift-BAT detection of a burst
  63. GRB 060121: Liverpool Telescopes optical limits
  64. GRB 060121: Swift XRT refined analysis
  65. Konus-Wind observation of GRB 060121
  66. GRB 060121: candidate optical counterpart
  67. GRB 060121: Infrared Observations
  68. GRB 060121: optical observations
  69. GRB 060121: Optical imaging
  70. GRB060121 - SDSS pre-burst observations
  71. HETE Alert 4006: MASTER promt optical limit
  72. GRB060117 - ATCA 3/6cm radio limits - correction
  73. GRB060117 - ATCA 3/6cm radio limits
  74. GRB 060116: photometric redshift - the farthest GRB?
  75. Konus-Wind observation of GRB 060117
  76. GRB 060116: UKIRT IR Observations
  77. GRB 060117: Refined analysis of the Swift-BAT burst
  78. GRB 060117: FRAM optical afterglow candidate
  79. GRB 060117: nearby galaxy
  80. GRB 060116: VLT optical observations
  81. GRB 060116: Refined analysis of the Swift-BAT burst
  82. GRB 060116: XRT refined analysis
  83. GRB 060116: IR Candidate Afterglow
  84. GRB 060116: Swift/UVOT upper limits
  85. GRB060115: REM observations
  86. GRB 060110: XRT position and analysis
  87. GRB 060116 : Lulin optical limit
  88. GRB060116: Faulkes North observation
  89. GRB 060116: Swift-BAT detection of a burst
  90. GRB 060115: Refined analysis of the Swift-BAT burst
  91. GRB 060115: Swift/UVOT upper limits
  92. GRB 060114: REM observations
  93. GRB 060115: Swift XRT refined analysis
  94. GRB 060114: Swift/UVOT Observations
  95. GRB060115, optical observation
  96. GRB 060115: MITSuME optical afterglow candidate
  97. GRB 060115: Swift detection of a burst
  98. GRB060114, optical observation
  99. GRB060114: Faulkes North observation
  100. GRB 060108: IR observations of afterglow

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