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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"

23413 results found.

  1. GRB 060116: VLT optical observations
  2. GRB 060115: PROMPT Observations
  3. GRB 060116: XRT refined analysis
  4. GRB 060116: IR Candidate Afterglow
  5. GRB 060116: Swift/UVOT upper limits
  6. GRB060115: REM observations
  7. GRB 060116 : Lulin optical limit
  8. GRB 060116: ROTSE-III Optical Limits
  9. GRB060116: Faulkes North observation
  10. GRB 060116: Swift-BAT detection of a burst
  11. GRB 060115: Swift/UVOT upper limits
  12. GRB 060114: REM observations
  13. GRB 060115: Swift XRT refined analysis
  14. GRB 060114: Swift/UVOT Observations
  15. GRB060115, optical observation
  16. GRB 060115: MITSuME optical afterglow candidate
  17. GRB 060115: Swift detection of a burst
  18. GRB 060114: Swift XRT upper limit
  19. GRB060114, optical observation
  20. GRB 060114: A long GRB detected by INTEGRAL
  21. GRB060114: Faulkes North observation
  22. GRB 060108: IR observations of afterglow
  23. GRB 060108: Evidence for an XRT Position Offset
  24. GRB 060110: KAIT observations
  25. GRB 060111A: refined UVOT anaysis
  26. GRB 060111B: MITSuME detection of optical afterglow
  27. GRB 060111B: TAROT optical observation
  28. GRB060111A: RTT150 optical observations
  29. GRB060111B: RTT150, possible host galaxy
  30. GRB 060111(a): P60 Observations
  31. GRB 060111B: Gualba observatory limit
  32. GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
  33. GRB 060111B: Swift detection of a burst
  34. GRB 060108: VLT K-band observations
  35. GRB 060111: TAROT optical observation
  36. GRB 060111: possible UVOT counterpart
  37. GRB060111 : XRT refined analysis
  38. GRB 060111: ROTSE-III Optical Limits
  39. GRB 060111: Swift detection of a burst
  40. GRB 060110: Mitsume optical observations
  41. GRB 060109: Swift-BAT refined analysis
  42. GRB 060108: z-band imaging from Gemini-North
  43. GRB 060110a: RAPTOR detection of early optical emission.
  44. GRB 060110: UKIRT K-band observations
  45. GRB 060110: IR Candidate Afterglow
  46. GRB060110, optical observation
  47. GRB 060110: Optical observation
  48. GRB 060110: Correction
  49. GRB 050110: IR Observations
  50. GRB 060110: Swift-BAT detection of a burst
  51. GRB 060109: Swift/UVOT upper limits
  52. GRB060109, optical observation
  53. GRB 060108: ISAS early observations and near IR upper limit
  54. GRB060108: P200 Ks Observations
  55. GRB 060108: early UKIRT K-band observations
  56. GRB 060109: Swift Detection of a long burst
  57. GRB 060108: a dark burst?
  58. GRB 060108: VLT J-band observations
  59. GRB 060108: Mitsume optical observations
  60. GRB 060108: Swift/UVOT upper limits
  61. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  62. GRB060108: SDSS pre-burst observations
  63. GRB060108: Faulkes Telescope observation
  64. GRB060108, optical observation
  65. GRB060108: Swift detection of its 100th GRB
  66. GRB 060105: ISAS observations and near IR upper limit
  67. GRB 060105: Swift/UVOT upper limits
  68. GRB 060105: Mitsume optical observations
  69. GRB 060105: BAT refined analysis
  70. GRB 060102 - no XRT afterglow
  71. GRB060105: Suzaku-XIS and -HXD observation plan
  72. GRB060105, optical observation
  73. GRB060105 : Kiso optical observation
  74. GRB060105: Swift detection of a bright long burst
  75. Swift-BAT trigger 175653 is not an astrophysical source
  76. GRB 060102: MDM Observation
  77. Swift-BAT trigger 175653 is probably not a GRB
  78. GRB 060102: Swift-BAT detection of a burst
  79. GRB 051221B: Optical Observations with Kuiper 1.54m
  80. GRB 051227: Likely host galaxy underlying afterglow position
  81. GRB 051227: optical observation
  82. GRB 051227: optical afterglow
  83. GRB 051227: Magellan r'-band Imaging/Astrometry
  84. GRB 051227: refined analysis of VLT images
  85. GRB 051227: P60 Observations
  86. GRB 051227: MDM Observation
  87. GRB 051227: R-band object in the XRT error circle
  88. GRB 051227: XRT refined analysis
  89. GRB051227: SDSS pre-burst observations
  90. GRB 051227, optical observation
  91. GRB 051227: Swift detection of a burst
  92. GRB051117B: optical observation
  93. GRB 051221A: MDM Optical Observations
  94. GRB 051221A: Detection at 251nm with Swift UVOT
  95. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  96. GRB 051221B: ROTSE-III Optical Limits
  97. GRB 051221B: TAROT optical limits
  98. GRB 051221B: Refined analysis of the Swift-BAT burst
  99. GRB 051221B: BOOTES optical observations.
  100. GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral

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