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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"

16089 results found.

  1. GRB 060206: High redshift burst
  2. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  3. GRB060206: Optical afterglow
  4. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  5. GRB060203: WHT Z-band observations
  6. GRB060204C: optical observation
  7. GRB 060204B: BVRi-band detections of optical afterglow
  8. GRB 060204A: FRAM optical observations
  9. GRB 060204C: optical observations
  10. GRB 060204B: ART early limit
  11. GRB060204B: Swift XRT Team Refined Analysis
  12. GRB 060204C: BOOTES-IR optical limits
  13. GRB 060204C: Liverpool Telescopes optical limit
  14. GRB 060204C: ROTSE-III Optical Limits
  15. GRB 060124: Radio Observations
  16. GRB 060204B: ART optical limit
  17. GRB060204B, optical observation
  18. GRB 060203: RTT150 optical observations
  19. GRB060203: Swift XRT Team Refined Analysis
  20. GRB060203 - Swift UVOT observation
  21. GRB 060203: P60 Confirmation of Optical Afterglow
  22. Possible GRB 060203: candidate optical counterpart
  23. Possible GRB 060203: optical observations at Asiago
  24. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  25. GRB060202, optical observation
  26. GRB060202: Faulkes North observation
  27. GRB 051211A: MDM Observations
  28. GRB060130: Optical imaging
  29. GRB 060130, SMARTS optical observations
  30. GRB 060130: FRAM optical observations
  31. Possible GRB 051221B: MDM Correction
  32. GRB050121: optical observation
  33. GRB050121b: optical observation
  34. GRB060124: optical observation
  35. GRB060124: optical observations
  36. GRB060124, BVRcIc field calibration
  37. GRB060124 optical observations
  38. GRB 060121: Probable Detection of NIR Afterglow
  39. GRB060124: optical observation
  40. GRB 060116 HST observations
  41. GRB 060124: HETE detection and spectrum of the main peak
  42. Refined XRT Position for GRB 060123
  43. GRB060124: detailed XRT analysis
  44. GRB 060124 Optical Observations
  45. GRB 060124: ART optical limits during the burst
  46. GRB060123: Optical and IR Imaging
  47. GRB 060124: Keck optical spectrum
  48. GRB 060124: MDM Optical Spectrum
  49. GRB 060124 : Optical observation at Xinglong and Kiso
  50. GRB060124: optical observations at Asiago
  51. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  52. GRB 060121: OHP optical limits
  53. GRB 060124: TAROT optical limits
  54. GRB 060124: Swift/UVOT Observation
  55. GRB 060124: Confirmation of the Afterglow
  56. GRB 060124: XRT position
  57. GRB 060124: Optical Afterglow Candidate from Tautenburg
  58. GRB060124, optical observation
  59. GRB 050124 : Kiso Optical limit
  60. GRB 060124: Optical Observations at Tautenburg
  61. GRB060124:MASTER optical observation
  62. GRB 060116: MARGE optical observations
  63. GRB 060121: Liverpool Telescopes optical limits
  64. GRB 060121: I-band Limits
  65. GRB 060121: Confirmation of Afterglow
  66. GRB 060121: candidate optical counterpart
  67. GRB 060121: optical observations
  68. GRB 060121: optical observations
  69. GRB 060121: Optical imaging
  70. GRB 060121 (=H4010): Results of preliminary spectral analysis
  71. GRB 060121: A bright short/hard GRB localized by HETE-2 SXC
  72. GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
  73. HETE Alert 4006: MASTER promt optical limit
  74. GRB060108: photometric redshift determination
  75. GRB 060117: FRAM refined analysis
  76. GRB 060117: FRAM optical afterglow candidate
  77. GRB 060116: VLT optical observations
  78. GRB060115: REM observations
  79. GRB 060116 : Lulin optical limit
  80. GRB 060116: ROTSE-III Optical Limits
  81. GRB 060115: absorption redshift
  82. GRB 060114: REM observations
  83. GRB 060115: Swift XRT refined analysis
  84. GRB 060115: OT finding chart
  85. GRB060115, optical observation
  86. GRB 060115: MITSuME optical afterglow candidate
  87. GRB060114, optical observation
  88. GRB 060108: IR observations of afterglow
  89. GRB 060108: Evidence for an XRT Position Offset
  90. GRB 060111B: Swift XRT refined analysis
  91. GRB 060111B: MITSuME detection of optical afterglow
  92. GRB 060111B: TAROT optical observation
  93. GRB060111A: RTT150 optical observations
  94. GRB060111B: RTT150, possible host galaxy
  95. GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
  96. GRB060111.2:_MASTER optical limit
  97. GRB 060111: TAROT optical observation
  98. GRB 060111: ROTSE-III Optical Limits
  99. GRB 060110: Mitsume optical observations
  100. GRB 060110a: RAPTOR detection of early optical emission.

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