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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"

28098 results found.

  1. GRB060115, optical observation
  2. GRB 060115: MITSuME optical afterglow candidate
  3. GRB 060115: Swift detection of a burst
  4. GRB060114, optical observation
  5. GRB060114: Faulkes North observation
  6. GRB 060108: IR observations of afterglow
  7. GRB 060108: Evidence for an XRT Position Offset
  8. GRB 060110: KAIT observations
  9. GRB 060111B: Swift XRT refined analysis
  10. GRB 060111B: MITSuME detection of optical afterglow
  11. GRB 060111B: TAROT optical observation
  12. GRB060111A: RTT150 optical observations
  13. GRB060111B: RTT150, possible host galaxy
  14. GRB 060111B: Refined analysis of the Swift-BAT burst
  15. GRB 060111(a): P60 Observations
  16. GRB 060111B: Gualba observatory limit
  17. GRB 060111B: Swift detection of a burst
  18. GRB 060111: Swift-BAT Refined Analysis
  19. GRB060111.2:_MASTER optical limit
  20. GRB 060108: VLT K-band observations
  21. GRB 060111: TAROT optical observation
  22. GRB 060111: Swift detection of a burst
  23. GRB 060110: Mitsume optical observations
  24. GRB 060110: Swift-BAT refined analysis
  25. GRB 060109: Swift-BAT refined analysis
  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: IR Candidate Afterglow
  30. GRB060110, optical observation
  31. GRB 060110: Correction
  32. Correction to GRB 060109 XRT analysis
  33. GRB 050110: IR Observations
  34. GRB 060109: Refined Swift-XRT analysis
  35. GRB 060109: Swift/UVOT upper limits
  36. GRB060109, optical observation
  37. GRB 060108: ISAS early observations and near IR upper limit
  38. GRB060108: P200 Ks Observations
  39. GRB 060108: early UKIRT K-band observations
  40. GRB 060108: a dark burst?
  41. GRB 060108: Refined XRT analysis
  42. GRB 060108: VLT J-band observations
  43. GRB 060108: Mitsume optical observations
  44. GRB 060108: Swift/UVOT upper limits
  45. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  46. GRB060108: SDSS pre-burst observations
  47. GRB060108: Faulkes Telescope observation
  48. GRB060108, optical observation
  49. GRB 060108: Refined analysis of the Swift-BAT burst
  50. GRB060108: Swift detection of its 100th GRB
  51. GRB 060105: ISAS observations and near IR upper limit
  52. GRB 060105: Swift/UVOT upper limits
  53. GRB 060105: Mitsume optical observations
  54. GRB 060105: BAT refined analysis
  55. GRB 060105: XRT refined analysis
  56. GRB060105: Suzaku-XIS and -HXD observation plan
  57. GRB060105, optical observation
  58. GRB060105: Swift detection of a bright long burst
  59. Swift-BAT trigger 175653 is probably not a GRB
  60. GRB 060102: Swift-BAT refined analysis
  61. GRB 060102: Swift-BAT detection of a burst
  62. GRB 051221B: Optical Observations with Kuiper 1.54m
  63. GRB 051227: Likely host galaxy underlying afterglow position
  64. GRB 051227: optical observation
  65. GRB 051227: optical afterglow
  66. GRB 051227: Magellan r'-band Imaging/Astrometry
  67. GRB 051227: refined analysis of VLT images
  68. GRB 051227: P60 Observations
  69. GRB 051227: MDM Observation
  70. GRB 051227: R-band object in the XRT error circle
  71. GRB 051227: XRT refined analysis
  72. GRB 051227: Further analysis of the Swift-BAT burst
  73. GRB 051227: Refined analysis of the Swift-BAT burst
  74. GRB051227: SDSS pre-burst observations
  75. GRB 051227, optical observation
  76. GRB051117B: optical observation
  77. Konus-Wind observation of GRB 051221A
  78. GRB051221A: Suzaku WAM observation of the prompt emission
  79. GRB 051221A: MDM Optical Observations
  80. GRB051016: analysis of the XMM-Newton observation
  81. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  82. GRB 051221B: TAROT optical limits
  83. GRB 051221B: Refined analysis of the Swift-BAT burst
  84. GRB 051221B: BOOTES optical observations.
  85. Swift-BAT detection of a possible burst
  86. GRB 051221: Swift XRT refined analysis
  87. GRB 051221: Swift/UVOT upper limits
  88. GRB 051221: No variability in Gemini data
  89. GRB 051221: Improved astrometry of the IR counterpart
  90. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  91. GRB 051221: Swift detection of a bright short burst
  92. Swift detection of an RS CVn flare star
  93. GRB051211A: possible optical candidate
  94. GRB 051215: near-infrared observations
  95. GRB051215 - SDSS pre-burst observations
  96. GRB 051215: Swift detection of a possible burst
  97. GRB051105: optical observations
  98. GRB 051213: Swift-BAT refined analysis
  99. GRB051211B: XRT refined analysis
  100. GRB 051211B, optical observation

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