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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"

20362 results found.

  1. GRB 060130: Swift/XRT observation
  2. GRB 060123: VLA Radio Observations
  3. GRB060130: Optical imaging
  4. GRB060130: REM infrared observations
  5. GRB 060130, SMARTS optical observations
  6. GRB 060130: FRAM optical observations
  7. GRB 060121: Confirmation of NIR Afterglow
  8. GRB060124, BVRcIc field calibration
  9. GRB 060121: Probable Detection of NIR Afterglow
  10. GRB 060116 HST observations
  11. Refined XRT Position for GRB 060123
  12. GRB 060124: ART optical limits during the burst
  13. GRB060123: Optical and IR Imaging
  14. GRB 060123: P200 Observations
  15. GRB 060124: R band Observations
  16. GRB 060124 : Optical observation at Xinglong and Kiso
  17. GRB060123: SDSS pre-burst observations
  18. GRB 060121: OHP optical limits
  19. GRB 060124: TAROT optical limits
  20. GRB060124, optical observation
  21. GRB 060124: Optical Observations at Tautenburg
  22. GRB 060124: Swift-BAT detection of a burst
  23. GRB 060121: Liverpool Telescopes optical limits
  24. GRB 060121: candidate optical counterpart
  25. GRB 060121: Infrared Observations
  26. GRB 060121: optical observations
  27. GRB 060121: Optical imaging
  28. GRB060121 - SDSS pre-burst observations
  29. HETE Alert 4006: MASTER promt optical limit
  30. GRB060117 - ATCA 3/6cm radio limits - correction
  31. GRB060117 - ATCA 3/6cm radio limits
  32. GRB 060116: UKIRT IR Observations
  33. GRB 060117: FRAM optical afterglow candidate
  34. GRB 060117: nearby galaxy
  35. GRB 060116: VLT optical observations
  36. GRB 060116: IR Candidate Afterglow
  37. GRB 060116: Swift/UVOT upper limits
  38. GRB060115: REM observations
  39. GRB060116: Faulkes North observation
  40. GRB 060116: Swift-BAT detection of a burst
  41. GRB 060115: Swift/UVOT upper limits
  42. GRB 060114: REM observations
  43. GRB 060114: Swift/UVOT Observations
  44. GRB060115, optical observation
  45. GRB 060115: MITSuME optical afterglow candidate
  46. GRB 060115: Swift detection of a burst
  47. GRB060114, optical observation
  48. GRB060114: Faulkes North observation
  49. GRB 060108: IR observations of afterglow
  50. GRB 060108: Evidence for an XRT Position Offset
  51. GRB 060110: KAIT observations
  52. GRB 060111B: MITSuME detection of optical afterglow
  53. GRB 060111B: TAROT optical observation
  54. GRB060111A: RTT150 optical observations
  55. GRB060111B: RTT150, possible host galaxy
  56. GRB 060111B: Refined analysis of the Swift-BAT burst
  57. GRB 060111(a): P60 Observations
  58. GRB 060111B: Gualba observatory limit
  59. GRB 060111B: Swift detection of a burst
  60. GRB 060108: VLT K-band observations
  61. GRB 060111: TAROT optical observation
  62. GRB 060111: Swift detection of a burst
  63. GRB 060110: Mitsume optical observations
  64. GRB 060108: z-band imaging from Gemini-North
  65. GRB 060110a: RAPTOR detection of early optical emission.
  66. GRB 060110: UKIRT K-band observations
  67. GRB 060110: IR Candidate Afterglow
  68. GRB060110, optical observation
  69. GRB 060110: Correction
  70. GRB 050110: IR Observations
  71. GRB 060109: Swift/UVOT upper limits
  72. GRB060109, optical observation
  73. GRB 060108: ISAS early observations and near IR upper limit
  74. GRB060108: P200 Ks Observations
  75. GRB 060108: early UKIRT K-band observations
  76. GRB 060108: VLT J-band observations
  77. GRB 060108: Mitsume optical observations
  78. GRB 060108: Swift/UVOT upper limits
  79. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  80. GRB060108: SDSS pre-burst observations
  81. GRB060108: Faulkes Telescope observation
  82. GRB060108, optical observation
  83. GRB 060108: Refined analysis of the Swift-BAT burst
  84. GRB060108: Swift detection of its 100th GRB
  85. GRB 060105: ISAS observations and near IR upper limit
  86. GRB 060105: Swift/UVOT upper limits
  87. GRB 060105: Mitsume optical observations
  88. GRB 060105: XRT refined analysis
  89. GRB060105: Suzaku-XIS and -HXD observation plan
  90. GRB060105, optical observation
  91. GRB060105: Swift detection of a bright long burst
  92. Swift-BAT trigger 175653 is probably not a GRB
  93. GRB 051221B: Optical Observations with Kuiper 1.54m
  94. GRB 051227: optical observation
  95. GRB 051227: optical afterglow
  96. GRB 051227: Magellan r'-band Imaging/Astrometry
  97. GRB 051227: refined analysis of VLT images
  98. GRB 051227: P60 Observations
  99. GRB 051227: MDM Observation
  100. GRB 051227: R-band object in the XRT error circle

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