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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"

20351 results found.

  1. GRB 060124: ART optical limits during the burst
  2. GRB060123: Optical and IR Imaging
  3. GRB 060123: P200 Observations
  4. GRB 060124: R band Observations
  5. GRB 060124 : Optical observation at Xinglong and Kiso
  6. GRB060123: SDSS pre-burst observations
  7. GRB 060121: OHP optical limits
  8. GRB 060124: TAROT optical limits
  9. GRB060124, optical observation
  10. GRB 060124: Optical Observations at Tautenburg
  11. GRB 060124: Swift-BAT detection of a burst
  12. GRB 060121: Liverpool Telescopes optical limits
  13. GRB 060121: candidate optical counterpart
  14. GRB 060121: Infrared Observations
  15. GRB 060121: optical observations
  16. GRB 060121: Optical imaging
  17. GRB060121 - SDSS pre-burst observations
  18. HETE Alert 4006: MASTER promt optical limit
  19. GRB060117 - ATCA 3/6cm radio limits - correction
  20. GRB060117 - ATCA 3/6cm radio limits
  21. GRB 060116: UKIRT IR Observations
  22. GRB 060117: FRAM optical afterglow candidate
  23. GRB 060117: nearby galaxy
  24. GRB 060116: VLT optical observations
  25. GRB 060116: IR Candidate Afterglow
  26. GRB 060116: Swift/UVOT upper limits
  27. GRB060115: REM observations
  28. GRB060116: Faulkes North observation
  29. GRB 060116: Swift-BAT detection of a burst
  30. GRB 060115: Swift/UVOT upper limits
  31. GRB 060114: REM observations
  32. GRB 060114: Swift/UVOT Observations
  33. GRB060115, optical observation
  34. GRB 060115: MITSuME optical afterglow candidate
  35. GRB 060115: Swift detection of a burst
  36. GRB060114, optical observation
  37. GRB060114: Faulkes North observation
  38. GRB 060108: IR observations of afterglow
  39. GRB 060108: Evidence for an XRT Position Offset
  40. GRB 060110: KAIT observations
  41. GRB 060111B: MITSuME detection of optical afterglow
  42. GRB 060111B: TAROT optical observation
  43. GRB060111A: RTT150 optical observations
  44. GRB060111B: RTT150, possible host galaxy
  45. GRB 060111B: Refined analysis of the Swift-BAT burst
  46. GRB 060111(a): P60 Observations
  47. GRB 060111B: Gualba observatory limit
  48. GRB 060111B: Swift detection of a burst
  49. GRB 060108: VLT K-band observations
  50. GRB 060111: TAROT optical observation
  51. GRB 060111: Swift detection of a burst
  52. GRB 060110: Mitsume optical observations
  53. GRB 060108: z-band imaging from Gemini-North
  54. GRB 060110a: RAPTOR detection of early optical emission.
  55. GRB 060110: UKIRT K-band observations
  56. GRB 060110: IR Candidate Afterglow
  57. GRB060110, optical observation
  58. GRB 060110: Correction
  59. GRB 050110: IR Observations
  60. GRB 060109: Swift/UVOT upper limits
  61. GRB060109, optical observation
  62. GRB 060108: ISAS early observations and near IR upper limit
  63. GRB060108: P200 Ks Observations
  64. GRB 060108: early UKIRT K-band observations
  65. GRB 060108: VLT J-band observations
  66. GRB 060108: Mitsume optical observations
  67. GRB 060108: Swift/UVOT upper limits
  68. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  69. GRB060108: SDSS pre-burst observations
  70. GRB060108: Faulkes Telescope observation
  71. GRB060108, optical observation
  72. GRB 060108: Refined analysis of the Swift-BAT burst
  73. GRB060108: Swift detection of its 100th GRB
  74. GRB 060105: ISAS observations and near IR upper limit
  75. GRB 060105: Swift/UVOT upper limits
  76. GRB 060105: Mitsume optical observations
  77. GRB 060105: XRT refined analysis
  78. GRB060105: Suzaku-XIS and -HXD observation plan
  79. GRB060105, optical observation
  80. GRB060105: Swift detection of a bright long burst
  81. Swift-BAT trigger 175653 is probably not a GRB
  82. GRB 051221B: Optical Observations with Kuiper 1.54m
  83. GRB 051227: optical observation
  84. GRB 051227: optical afterglow
  85. GRB 051227: Magellan r'-band Imaging/Astrometry
  86. GRB 051227: refined analysis of VLT images
  87. GRB 051227: P60 Observations
  88. GRB 051227: MDM Observation
  89. GRB 051227: R-band object in the XRT error circle
  90. GRB051227: SDSS pre-burst observations
  91. GRB 051227, optical observation
  92. GRB 051227: Swift detection of a burst
  93. GRB051117B: optical observation
  94. Konus-Wind observation of GRB 051221A
  95. GRB 051221A: MDM Optical Observations
  96. GRB 051221B: TAROT optical limits
  97. Swift-BAT detection of a possible burst
  98. GRB 051221: Swift/UVOT upper limits
  99. GRB 051221: Improved astrometry of the IR counterpart
  100. GRB 051221: Swift detection of a bright short burst

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