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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"

26500 results found.

  1. GRB 060121: optical observations
  2. GRB 060121: Optical imaging
  3. GRB060121 - SDSS pre-burst observations
  4. GRB 060121 (=H4010): Results of preliminary spectral analysis
  5. GRB 060121: A bright short/hard GRB localized by HETE-2 SXC
  6. GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
  7. HETE Alert 4006: MASTER promt optical limit
  8. GRB060117 - ATCA 3/6cm radio limits - correction
  9. GRB060117 - ATCA 3/6cm radio limits
  10. GRB 060116: UKIRT IR Observations
  11. GRB 060117: FRAM optical afterglow candidate
  12. GRB 060117: nearby galaxy
  13. GRB 060116: VLT optical observations
  14. GRB 060116: XRT refined analysis
  15. GRB 060116: IR Candidate Afterglow
  16. GRB 060116: Swift/UVOT upper limits
  17. GRB060115: REM observations
  18. GRB 060110: XRT position and analysis
  19. GRB060116: Faulkes North observation
  20. GRB 060116: Swift-BAT detection of a burst
  21. GRB 060115: Swift/UVOT upper limits
  22. GRB 060114: REM observations
  23. GRB 060115: Swift XRT refined analysis
  24. GRB 060114: Swift/UVOT Observations
  25. GRB060115, optical observation
  26. GRB 060115: MITSuME optical afterglow candidate
  27. GRB 060115: Swift detection of a burst
  28. GRB 060114: Swift XRT upper limit
  29. GRB060114, optical observation
  30. GRB 060114: refined position
  31. GRB060114: Faulkes North observation
  32. GRB 060108: IR observations of afterglow
  33. GRB060108: Faulkes North afterglow evidence
  34. GRB 060108: Evidence for an XRT Position Offset
  35. GRB 060110: KAIT observations
  36. GRB 060111B: Swift XRT refined analysis
  37. GRB 060111B: MITSuME detection of optical afterglow
  38. GRB 060111B: TAROT optical observation
  39. GRB060111A: RTT150 optical observations
  40. GRB060111B: RTT150, possible host galaxy
  41. GRB 060111B: Refined analysis of the Swift-BAT burst
  42. GRB 060111(a): P60 Observations
  43. GRB 060111B: Gualba observatory limit
  44. GRB 060111B: Swift detection of a burst
  45. GRB 060108: VLT K-band observations
  46. GRB 060111: TAROT optical observation
  47. GRB060111 : XRT refined analysis
  48. GRB 060111: Swift detection of a burst
  49. GRB 060110: Mitsume optical observations
  50. GRB 060110: Swift-BAT refined analysis
  51. GRB 060109: Swift-BAT refined analysis
  52. GRB 060108: z-band imaging from Gemini-North
  53. GRB 060110a: RAPTOR detection of early optical emission.
  54. GRB 060110: UKIRT K-band observations
  55. GRB 060110: IR Candidate Afterglow
  56. GRB060110, optical observation
  57. GRB 060110: Optical observation
  58. GRB 060110: Correction
  59. Correction to GRB 060109 XRT analysis
  60. GRB 050110: IR Observations
  61. GRB 060110: Swift-BAT detection of a burst
  62. GRB 060109: Refined Swift-XRT analysis
  63. GRB 060109: Swift/UVOT upper limits
  64. GRB060109, optical observation
  65. GRB 060108: ISAS early observations and near IR upper limit
  66. GRB060108: P200 Ks Observations
  67. GRB 060108: early UKIRT K-band observations
  68. GRB 060108: Refined XRT analysis
  69. GRB 060108: VLT J-band observations
  70. GRB 060108: Mitsume optical observations
  71. GRB 060108: Swift/UVOT upper limits
  72. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  73. GRB060108: SDSS pre-burst observations
  74. GRB060108: Faulkes Telescope observation
  75. GRB060108, optical observation
  76. GRB060108: Swift detection of its 100th GRB
  77. Konus-Wind observation of GRB 060105
  78. GRB 060105: ISAS observations and near IR upper limit
  79. GRB 060105: Swift/UVOT upper limits
  80. GRB 060105: Mitsume optical observations
  81. GRB 060102 - no XRT afterglow
  82. GRB 060105: XRT refined analysis
  83. GRB060105: Suzaku-XIS and -HXD observation plan
  84. GRB060105, optical observation
  85. GRB060105: Swift detection of a bright long burst
  86. Swift-BAT trigger 175653 is probably not a GRB
  87. GRB 060102: Swift-BAT refined analysis
  88. Time Correction to GRB 060102
  89. GRB 051221B: Optical Observations with Kuiper 1.54m
  90. GRB 051227: Likely host galaxy underlying afterglow position
  91. GRB 051227: optical observation
  92. GRB 051227: optical afterglow
  93. GRB 051227: Magellan r'-band Imaging/Astrometry
  94. GRB 051227: refined analysis of VLT images
  95. GRB 051227: P60 Observations
  96. GRB 051227: MDM Observation
  97. GRB 051227: R-band object in the XRT error circle
  98. GRB 051227: Joint Swift-HETE Spectral Analysis
  99. GRB 051227: XRT refined analysis
  100. GRB 051227: Further analysis of the Swift-BAT burst

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