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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"

15987 results found.

  1. GRB060105: optical observations
  2. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  3. GRB 050826: Optical Afterglow and Host Galaxy
  4. GRB060211b: optical observation
  5. GRB 060210: Optical Observations
  6. GRB060211: Faulkes North observation
  7. GRB 060211: ROTSE-III Optical Limits
  8. GRB060210: Swift XRT Refined Analysis
  9. GRB060206, optical observations
  10. GRB 060210 : Xinglong and Lulin optical limit
  11. GRB060210: Optical Observations
  12. GRB060210: Gemini absorption spectroscopy
  13. GRB060210: Early Optical Observations
  14. GRB 060210: optical evolution
  15. GRB060210: Optical afterglow
  16. GRB060209: RTT150 optical observations
  17. GRB 060209 : TAROT optical observation
  18. GRB060209A: MASTER optical observation
  19. GRB 060206: WSRT Radio Observations
  20. GRB 060121 : WIDGET Pre-trigger limit
  21. GRB 060206: optical observations at Asiago
  22. Orphan GRB Afterglow candidate
  23. GRB 060206: Subaru/FOCAS optical spectroscopy
  24. GRB 060206: Super-LOTIS observations
  25. GRB060204A: Swift/UVOT observations
  26. GRB 060206 : Lulin optical observations
  27. GRB060206: Swift XRT Refined Analysis
  28. GRB060206: Liverpool Telescope observation
  29. GRB060206: P60 Optical Observations
  30. GRB060206: Swift XRT Position
  31. GRB 060206: RAPTOR observations of afterglow candidate variability.
  32. GRB 060206: High redshift burst
  33. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  34. GRB060206: Optical afterglow
  35. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  36. GRB060203: WHT Z-band observations
  37. GRB060204C: optical observation
  38. GRB 060204B: BVRi-band detections of optical afterglow
  39. GRB 060204A: FRAM optical observations
  40. GRB 060204C: optical observations
  41. GRB 060204B: ART early limit
  42. GRB060204B: Swift XRT Team Refined Analysis
  43. GRB 060204C: BOOTES-IR optical limits
  44. GRB 060204C: Liverpool Telescopes optical limit
  45. GRB 060204C: ROTSE-III Optical Limits
  46. GRB 060124: Radio Observations
  47. GRB 060204B: ART optical limit
  48. GRB060204B, optical observation
  49. GRB 060203: RTT150 optical observations
  50. GRB060203: Swift XRT Team Refined Analysis
  51. GRB060203 - Swift UVOT observation
  52. GRB 060203: P60 Confirmation of Optical Afterglow
  53. Possible GRB 060203: candidate optical counterpart
  54. Possible GRB 060203: optical observations at Asiago
  55. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  56. GRB060202, optical observation
  57. GRB060202: Faulkes North observation
  58. GRB 051211A: MDM Observations
  59. GRB060130: Optical imaging
  60. GRB 060130, SMARTS optical observations
  61. GRB 060130: FRAM optical observations
  62. Possible GRB 051221B: MDM Correction
  63. GRB050121: optical observation
  64. GRB050121b: optical observation
  65. GRB060124: optical observation
  66. GRB060124: optical observations
  67. GRB060124, BVRcIc field calibration
  68. GRB060124 optical observations
  69. GRB 060121: Probable Detection of NIR Afterglow
  70. GRB060124: optical observation
  71. GRB 060116 HST observations
  72. GRB 060124: HETE detection and spectrum of the main peak
  73. Refined XRT Position for GRB 060123
  74. GRB060124: detailed XRT analysis
  75. GRB 060124 Optical Observations
  76. GRB 060124: ART optical limits during the burst
  77. GRB060123: Optical and IR Imaging
  78. GRB 060124: Keck optical spectrum
  79. GRB 060124: MDM Optical Spectrum
  80. GRB 060124 : Optical observation at Xinglong and Kiso
  81. GRB060124: optical observations at Asiago
  82. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  83. GRB 060121: OHP optical limits
  84. GRB 060124: TAROT optical limits
  85. GRB 060124: Swift/UVOT Observation
  86. GRB 060124: Confirmation of the Afterglow
  87. GRB 060124: XRT position
  88. GRB 060124: Optical Afterglow Candidate from Tautenburg
  89. GRB060124, optical observation
  90. GRB 050124 : Kiso Optical limit
  91. GRB 060124: Optical Observations at Tautenburg
  92. GRB060124:MASTER optical observation
  93. GRB 060116: MARGE optical observations
  94. GRB 060121: Liverpool Telescopes optical limits
  95. GRB 060121: I-band Limits
  96. GRB 060121: Confirmation of Afterglow
  97. GRB 060121: candidate optical counterpart
  98. GRB 060121: optical observations
  99. GRB 060121: optical observations
  100. GRB 060121: Optical imaging

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