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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"

16110 results found.

  1. GRB060210: Gemini absorption spectroscopy
  2. GRB060210: Early Optical Observations
  3. GRB 060210: optical evolution
  4. GRB060210: Optical afterglow
  5. GRB060209: RTT150 optical observations
  6. GRB 060209 : TAROT optical observation
  7. GRB060209A: MASTER optical observation
  8. GRB 060206: WSRT Radio Observations
  9. GRB 060206: More PROMPT Detections
  10. GRB 060121 : WIDGET Pre-trigger limit
  11. GRB 060206: optical observations at Asiago
  12. Orphan GRB Afterglow candidate
  13. GRB 060206: Subaru/FOCAS optical spectroscopy
  14. GRB 060206: Super-LOTIS observations
  15. GRB060204A: Swift/UVOT observations
  16. GRB 060206 : Lulin optical observations
  17. GRB060206: Swift XRT Refined Analysis
  18. GRB060206: Liverpool Telescope observation
  19. GRB060206: P60 Optical Observations
  20. GRB060206: Swift XRT Position
  21. GRB 060206: RAPTOR observations of afterglow candidate variability.
  22. GRB 060206: High redshift burst
  23. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  24. GRB060206: Optical afterglow
  25. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  26. GRB060203: WHT Z-band observations
  27. GRB060204C: optical observation
  28. GRB 060204B: BVRi-band detections of optical afterglow
  29. GRB 060204A: FRAM optical observations
  30. GRB 060204C: optical observations
  31. GRB 060204B: ART early limit
  32. GRB060204B: Swift XRT Team Refined Analysis
  33. GRB 060204C: BOOTES-IR optical limits
  34. GRB 060204C: Liverpool Telescopes optical limit
  35. GRB 060204C: ROTSE-III Optical Limits
  36. GRB 060124: Radio Observations
  37. GRB 060204B: ART optical limit
  38. GRB060204B, optical observation
  39. GRB 060203: RTT150 optical observations
  40. GRB060203: Swift XRT Team Refined Analysis
  41. GRB060203 - Swift UVOT observation
  42. GRB 060203: P60 Confirmation of Optical Afterglow
  43. Possible GRB 060203: candidate optical counterpart
  44. Possible GRB 060203: optical observations at Asiago
  45. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  46. GRB060202, optical observation
  47. GRB060202: Faulkes North observation
  48. GRB 051211A: MDM Observations
  49. GRB060130: Optical imaging
  50. GRB 060130, SMARTS optical observations
  51. GRB 060130: FRAM optical observations
  52. Possible GRB 051221B: MDM Correction
  53. GRB050121: optical observation
  54. GRB050121b: optical observation
  55. GRB060124: optical observation
  56. GRB060124: optical observations
  57. GRB060124, BVRcIc field calibration
  58. GRB060124 optical observations
  59. GRB 060121: Probable Detection of NIR Afterglow
  60. GRB060124: optical observation
  61. GRB 060116 HST observations
  62. GRB 060124: HETE detection and spectrum of the main peak
  63. Refined XRT Position for GRB 060123
  64. GRB060124: detailed XRT analysis
  65. GRB 060124 Optical Observations
  66. GRB 060124: ART optical limits during the burst
  67. GRB060123: Optical and IR Imaging
  68. GRB 060124: Keck optical spectrum
  69. GRB 060124: MDM Optical Spectrum
  70. GRB 060124 : Optical observation at Xinglong and Kiso
  71. GRB060124: optical observations at Asiago
  72. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  73. GRB 060121: OHP optical limits
  74. GRB 060124: TAROT optical limits
  75. GRB 060124: Swift/UVOT Observation
  76. GRB 060124: Confirmation of the Afterglow
  77. GRB 060124: XRT position
  78. GRB 060124: Optical Afterglow Candidate from Tautenburg
  79. GRB060124, optical observation
  80. GRB 050124 : Kiso Optical limit
  81. GRB 060124: Optical Observations at Tautenburg
  82. GRB060124:MASTER optical observation
  83. GRB 060116: MARGE optical observations
  84. GRB 060121: Liverpool Telescopes optical limits
  85. GRB 060121: I-band Limits
  86. GRB 060121: Confirmation of Afterglow
  87. GRB 060121: candidate optical counterpart
  88. GRB 060121: optical observations
  89. GRB 060121: optical observations
  90. GRB 060121: Optical imaging
  91. GRB 060121 (=H4010): Results of preliminary spectral analysis
  92. GRB 060121: A bright short/hard GRB localized by HETE-2 SXC
  93. GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
  94. HETE Alert 4006: MASTER promt optical limit
  95. GRB060108: photometric redshift determination
  96. GRB 060117: FRAM refined analysis
  97. GRB 060117: FRAM optical afterglow candidate
  98. GRB 060116: VLT optical observations
  99. GRB060115: REM observations
  100. GRB 060116 : Lulin optical limit

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