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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"

16159 results found.

  1. GRB050827: RTT150 optical observations
  2. Subaru Observations of GRB050724
  3. GRB 050826: Optical Candidate
  4. GRB050824, HETE-2 Observation
  5. GRB050826: Swift/UVOT early upper limits
  6. GRB050824: First 2 hours of power low optical decay?
  7. Possible GRB050825:MASTER optical observations
  8. GRB050824: CORRECTION to UVOT observing times
  9. GRB050824: Swift/UVOT detection of fading afterglow
  10. GRB050824, I-band imaging
  11. GRB050824: Radio Observations
  12. GRB 050824: XRT refined analysis and possible afterglow detection
  13. GRB 050824: BAT refined analysis of a soft weak burst
  14. GRB050824: MASTER:OT decay
  15. GRB050805a: MASTER optical candidat
  16. GRB 050824: ROTSE-III Optical Limits
  17. GRB 050824 optical candidate
  18. GRB050820A: RTT150 optical observations
  19. GRB050815: Maidanak optical observation
  20. VLT/UVES spectroscopy of GRB050820
  21. GRB050820B at FRAM
  22. GRB050820A: RTT150 optical observations
  23. GRB 050820a - corrections to GCN 3846
  24. GRB 050822: ROTSE-III Prompt Optical Limits
  25. GRB050820A: Radio Observation
  26. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  27. GRB050820a BVRcIc field photometry
  28. GRB050820: refined XRT analysis
  29. GRB 050820 Swift-BAT refined analysis
  30. GRB 050820: P60 Temporal Decay Index
  31. GRB 050820: High Resolution Spectroscopy from Keck
  32. GRB050819: RTT150 optical observations
  33. GRB050820: Optical afterglow from P60
  34. GRB 050817: Optical observations
  35. GRB 050815: Radio Observation
  36. GRB050814: Radio Observation
  37. GRB050817: Negative Optical Observations
  38. GRB050817: Swift-BAT Detection of a burst
  39. GRB 050814: continued fading
  40. GRB050815: Optical afterglow detection by Swift UVOT
  41. GRB 050815: ROTSE-III Optical Limits
  42. GRB050814: Fading red source
  43. GRB050814: P60 Optical Afterglow Candidate
  44. GRB050813: RTT150 optical observations
  45. GRB 050813: KAIT optical limit
  46. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  47. GRB050803: CrAO optical observations, no OT candidate
  48. GRB 050807: ROTSE-III Optical Limits
  49. GRB 050730, optical observation
  50. GRB050805b: CrAO optical limit
  51. GRB050805a : Null detection report
  52. GRB050730, optical observations
  53. GRB050803, optical observations
  54. GRB 050805b: OHP optical limits
  55. GRB 050805b: TAROT optical limits
  56. GRB050805b: MASTER optical observations
  57. GRB050805a: MASTER optical candidat
  58. GRB050802: TNG optical observations
  59. GRB050803: Radio Observation
  60. GRB 050803: RTT150 optical observations
  61. GRB050801: Radio Observation
  62. GRB050730: Radio Detection
  63. GRB050803: CrAO optical observations, possible OT candidate
  64. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  65. GRB 050802.422: Fading of the afterglow and detection of the host
  66. GRB050803: MASTER further analys
  67. GRB 050803, optical observations
  68. GRB 050803: early Swift XRT analysis results
  69. GRB 050803: TAROT optical limits
  70. GRB050803: MASTER optical observations
  71. GRB050802: Tentative absorption redshift
  72. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  73. GRB 050802: Swift/UVOT optical and UV detections
  74. GRB050802: CrAO optical observations
  75. GRB050801: Unchanged decay slope
  76. GRB 050730: OHP optical observations
  77. GRB 050802 : Lulin Optical follow-up observation
  78. GRB050801: Optical photometry and decay index
  79. GRB050801: Swift/UVOT Optical and UV detections
  80. GRB 050801, SMARTS optical/IR afterglow observations
  81. GRB 050801: ROTSE-III Early Afterglow Break
  82. GRB 050730: early TAROT optical observations
  83. GRB 050730: RTT150 optical observations
  84. GRB 050730, spectra and optical photometry
  85. GRB 050730: Swift XRT afterglow observations
  86. GRB050730, afterglow observations
  87. GRB050730: confirmation of redshift
  88. GRB 050730, SMARTS optical/IR afterglow observations
  89. GRB050730: Liverpool Telescope optical observations
  90. GRB 050730, optical candidate
  91. GRB050730: Swift-BAT detection of a weak burst
  92. GRB 050713A: Swift XRT extended light curve
  93. GRB050713b: Maidanak optical observations
  94. GRB 050724: WHT optical observations
  95. GRB050726: Swift UVOT observations
  96. GRB050724: Refined Radio Position
  97. GRB 050724, SMARTS optical/IR afterglow observations
  98. GRB 050726, SMARTS optical/IR observations
  99. GRB 050727: RTT150 optical observations
  100. GRB050727: KAIT optical limit

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