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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"

42203 results found.

  1. GRB 060114: refined position
  2. GRB 060114: A long GRB detected by INTEGRAL
  3. GRB 060108: IR observations of afterglow
  4. GRB060108: Faulkes North afterglow evidence
  5. GRB 060108: Evidence for an XRT Position Offset
  6. GRB 060110: KAIT observations
  7. GRB 060111B: Swift XRT refined analysis
  8. GRB 060111B: MITSuME detection of optical afterglow
  9. GRB 060111B: TAROT optical observation
  10. GRB060111A: RTT150 optical observations
  11. GRB060111B: RTT150, possible host galaxy
  12. GRB 060110: MARGE observations
  13. GRB 060111(a): P60 Observations
  14. GRB 060111B: Gualba observatory limit
  15. GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
  16. GRB 060111B: Swift detection of a burst
  17. GRB 060111: Swift-BAT Refined Analysis
  18. GRB060111.2:_MASTER optical limit
  19. GRB 060108: VLT K-band observations
  20. GRB 060111: TAROT optical observation
  21. GRB 060111: possible UVOT counterpart
  22. GRB060111 : XRT refined analysis
  23. GRB 060111: ROTSE-III Optical Limits
  24. GRB 060111: Swift detection of a burst
  25. GRB 060110: Mitsume optical observations
  26. GRB 060108: z-band imaging from Gemini-North
  27. GRB 060110a: RAPTOR detection of early optical emission.
  28. GRB 060110: UKIRT K-band observations
  29. GRB 060110: ROTSE-III Confirmation of Optical Counterpart
  30. GRB060110, optical observation
  31. GRB 060110: Super-LOTIS observations
  32. GRB 060110: Optical observation
  33. GRB 060110: Correction
  34. GRB 060110: Optical limit
  35. GRB 060110: Swift-BAT detection of a burst
  36. GRB 060109: Refined Swift-XRT analysis
  37. GRB 060109: Swift/UVOT upper limits
  38. GRB060109, optical observation
  39. GRB 060108: ISAS early observations and near IR upper limit
  40. GRB060108: P200 Ks Observations
  41. GRB 060108: early UKIRT K-band observations
  42. GRB 060109: Swift Detection of a long burst
  43. GRB 060108: a dark burst?
  44. GRB 060108: Refined XRT analysis
  45. GRB 060108: VLT J-band observations
  46. GRB 060108: Mitsume optical observations
  47. GRB 060108: Swift/UVOT upper limits
  48. GRB060108: SDSS pre-burst observations
  49. GRB060108: Faulkes Telescope observation
  50. GRB060108, optical observation
  51. GRB 060108: Refined analysis of the Swift-BAT burst
  52. GRB 060108: Swift XRT position
  53. GRB060108: Swift detection of its 100th GRB
  54. GRB 060105: Radio observations
  55. GRB 060105: MDM Observation
  56. Konus-Wind observation of GRB 060105
  57. GRB 060105: ISAS observations and near IR upper limit
  58. GRB 060105: Mitsume optical observations
  59. GRB 060105: BAT refined analysis
  60. GRB 060102 - no XRT afterglow
  61. GRB 060105: XRT refined analysis
  62. GRB060105: Suzaku-XIS and -HXD observation plan
  63. GRB060105, optical observation
  64. GRB060105 : Kiso optical observation
  65. GRB060105: Swift detection of a bright long burst
  66. Swift-BAT trigger 175653 is not an astrophysical source
  67. GRB 060102: MDM Observation
  68. Swift-BAT trigger 175653 is probably not a GRB
  69. GRB 060102: Swift-BAT refined analysis
  70. GRB 060102: Swift-BAT detection of a burst
  71. GRB051211B: optical observations
  72. GRB051227: SARA Observations
  73. GRB 051221B: Optical Observations with Kuiper 1.54m
  74. GRB 051227: Likely host galaxy underlying afterglow position
  75. GRB 051227: optical observation
  76. GRB 051221A: VLA Radio Observations
  77. GRB051227: Radio Observations
  78. GRB 051227: Confirmed fading from Gemini observations
  79. GRB051227: further analysis of VLT images
  80. GRB 051227: optical afterglow
  81. GRB 051227: Swift/UVOT Upper Limits (Possible U-band
  82. GRB 051227: Gemini observations
  83. GRB 051227: Keck Spectroscopy
  84. GRB 051227: Magellan r'-band Imaging/Astrometry
  85. GRB 051227: refined analysis of VLT images
  86. GRB 051227: P60 Observations
  87. GRB 051227: MDM Observation
  88. GRB 051227: R-band object in the XRT error circle
  89. GRB 051227: Joint Swift-HETE Spectral Analysis
  90. GRB 051227: XRT refined analysis
  91. GRB 051227: Further analysis of the Swift-BAT burst
  92. GRB 051227: Refined analysis of the Swift-BAT burst
  93. GRB051227: SDSS pre-burst observations
  94. GRB 051227, optical observation
  95. GRB 051227: Swift detection of a burst
  96. GRB051117B: optical observation
  97. Konus-Wind observation of GRB 051221A
  98. GRB051221A: Suzaku WAM observation of the prompt emission
  99. GRB 051221A: MDM Optical Observations
  100. GRB051016: analysis of the XMM-Newton observation

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