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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"

7258 results found.

  1. GRB 060115: OT photometry with MITSuME
  2. GRB 060115: Swift/UVOT upper limits
  3. GRB 060115: MITSuME optical afterglow candidate
  4. GRB 060115: Swift detection of a burst
  5. GRB060114: Faulkes North observation
  6. GRB060108: Faulkes North afterglow evidence
  7. GRB 060111A: refined UVOT anaysis
  8. GRB 060111B: MITSuME detection of optical afterglow
  9. GRB060111A: RTT150 optical observations
  10. GRB 060111B: Swift detection of a burst
  11. GRB060111.2:_MASTER optical limit
  12. GRB 060111: possible UVOT counterpart
  13. GRB 060111: Swift detection of a burst
  14. GRB 060110: Mitsume optical observations
  15. GRB 060110: IR Candidate Afterglow
  16. GRB 060110: Super-LOTIS observations
  17. GRB 060110: Optical observation
  18. GRB 060110: Correction
  19. GRB 060110: Optical limit
  20. GRB 060109: Swift Detection of a long burst
  21. GRB060108: Faulkes Telescope observation
  22. GRB060108: Swift detection of its 100th GRB
  23. GRB 060105: Swift/UVOT upper limits
  24. GRB 060102 - no XRT afterglow
  25. GRB060105 : Kiso optical observation
  26. GRB060105: Swift detection of a bright long burst
  27. Swift-BAT trigger 175653 is not an astrophysical source
  28. GRB051211B: optical observations
  29. GRB 051221B: Optical Observations with Kuiper 1.54m
  30. GRB 051227: optical observation
  31. GRB 051227: P60 Observations
  32. GRB 051227: R-band object in the XRT error circle
  33. GRB 051227: Swift detection of a burst
  34. GRB051117B: optical observation
  35. GRB 051221: Continued fading of optical afterglow
  36. GRB 051221A: RAPTOR Fading Counterpart Constraint
  37. Swift-BAT detection of a possible burst
  38. GRB 051221: Swift/UVOT upper limits
  39. GRB 051221: Swift detection of a bright short burst
  40. GRB051211A: possible optical candidate
  41. GRB 051215: A short GRB in a cluster?
  42. GRB 051211B: Swift XRT confirmation of the afterglow
  43. GRB051211B: Liverpool Telescope observation
  44. GRB 051211b: RTT150 optical observations
  45. GRB 051211B: Swift XRT Observations
  46. GRB 051211B: a possible optical detection by TAROT
  47. GRB051111: Rc optical observations
  48. GRB 051117B: Swift detection of a burst
  49. Faulkes Telescope R-band detection of GRB051111
  50. GRB 051109a: IR Detections
  51. GRB051103: MASTER: OT limit and host galaxy candidates
  52. GRB 051105A, 2nd epoch optical observations
  53. GRB051103:_MASTER_optical_observations
  54. GRB 051105: Optical limit
  55. GRB051016B: optical observation
  56. GRB051028: optical observations
  57. GRB051028: confirmation of the afterglow
  58. GRB051028: WHT optical candidate
  59. GRB051028:MASTER observations
  60. GRB051028:MASTER optical observations
  61. GRB 051022: XRT Refined Spectral and Temporal Analysis
  62. GRB051021A: Swift XRT refined analysis
  63. GRB051021b: Magellan IR Imaging
  64. GRB 051021, SMARTS optical/IR observations
  65. GRB 051021: Optical observations
  66. GRB 051021: Optical observations and candidate afterglow
  67. GRB051021.63
  68. GRB051021.6: MASTER optical observation
  69. GRB 051016b: Optical limit
  70. Afterglow candidate of GRB 051016B observed at Lulin
  71. GRB 051016b: Gemini Near IR Observations
  72. GRB050805A: Rc optical observations
  73. GRB051008: optical candidate
  74. GRB051011: MASTER optical observation
  75. GRB051008 - Swift UVOT upper limits
  76. GRB 051008, optical observations
  77. GRB 051008: Swift UVOT Candidate
  78. grb test
  79. GRB050925: Faulkes Telescope North R-band limit
  80. GRB 050911, optical content of Swift/XRT error box
  81. GRB050911: Swift-XRT position
  82. GRB050908 : Swift-XRT refined analysis
  83. GRB 050908: Optical observations
  84. Gemini Spectroscopy of GRB 050908
  85. GRB 050908: P60 Confirmation of Optical Afterglow
  86. GRB 050908: Optical Observations
  87. GRB 050904: Subaru Optical Spectroscopy
  88. GRB 050906: Swift-BAT refined analysis
  89. GRB 050904: Keck I-band Imaging
  90. GRB 050904: TAROT optical measurements
  91. GRB 050827: Optical Limit
  92. GRB 050826 : Lulin R band observation
  93. GRB 050826: Optical Candidate
  94. GRB050824: MASTER final analysis of the OT observations
  95. GRB050824, I-band imaging
  96. GRB 050824: XRT refined analysis and possible afterglow detection
  97. GRB 050824: BAT refined analysis of a soft weak burst
  98. GRB050824: MASTER:OT decay
  99. GRB 050824 optical candidate
  100. GRB050814: P60 Optical Afterglow Candidate

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