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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"

20884 results found.

  1. GRB 060111(a): P60 Observations
  2. GRB 060111B: Gualba observatory limit
  3. GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
  4. GRB 060111B: Swift detection of a burst
  5. GRB 060108: VLT K-band observations
  6. GRB 060111: TAROT optical observation
  7. GRB 060111: possible UVOT counterpart
  8. GRB060111 : XRT refined analysis
  9. GRB 060111: ROTSE-III Optical Limits
  10. GRB 060111: Swift detection of a burst
  11. GRB 060110: Mitsume optical observations
  12. GRB 060109: Swift-BAT refined analysis
  13. GRB 060108: z-band imaging from Gemini-North
  14. GRB 060110a: RAPTOR detection of early optical emission.
  15. GRB 060110: UKIRT K-band observations
  16. GRB 060110: IR Candidate Afterglow
  17. GRB060110, optical observation
  18. GRB 060110: Optical observation
  19. GRB 060110: Correction
  20. GRB 050110: IR Observations
  21. GRB 060110: Swift-BAT detection of a burst
  22. GRB 060109: Swift/UVOT upper limits
  23. GRB060109, optical observation
  24. GRB 060108: ISAS early observations and near IR upper limit
  25. GRB060108: P200 Ks Observations
  26. GRB 060108: early UKIRT K-band observations
  27. GRB 060109: Swift Detection of a long burst
  28. GRB 060108: a dark burst?
  29. GRB 060108: VLT J-band observations
  30. GRB 060108: Mitsume optical observations
  31. GRB 060108: Swift/UVOT upper limits
  32. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  33. GRB060108: SDSS pre-burst observations
  34. GRB060108: Faulkes Telescope observation
  35. GRB060108, optical observation
  36. GRB060108: Swift detection of its 100th GRB
  37. GRB 060105: ISAS observations and near IR upper limit
  38. GRB 060105: Swift/UVOT upper limits
  39. GRB 060105: Mitsume optical observations
  40. GRB 060105: BAT refined analysis
  41. GRB 060102 - no XRT afterglow
  42. GRB060105: Suzaku-XIS and -HXD observation plan
  43. GRB060105, optical observation
  44. GRB060105 : Kiso optical observation
  45. GRB060105: Swift detection of a bright long burst
  46. Swift-BAT trigger 175653 is not an astrophysical source
  47. GRB 060102: MDM Observation
  48. Swift-BAT trigger 175653 is probably not a GRB
  49. GRB 060102: Swift-BAT detection of a burst
  50. GRB 051221B: Optical Observations with Kuiper 1.54m
  51. GRB 051227: Likely host galaxy underlying afterglow position
  52. GRB 051227: optical observation
  53. GRB 051227: optical afterglow
  54. GRB 051227: Magellan r'-band Imaging/Astrometry
  55. GRB 051227: refined analysis of VLT images
  56. GRB 051227: P60 Observations
  57. GRB 051227: MDM Observation
  58. GRB 051227: R-band object in the XRT error circle
  59. GRB 051227: XRT refined analysis
  60. GRB051227: SDSS pre-burst observations
  61. GRB 051227, optical observation
  62. GRB 051227: Swift detection of a burst
  63. GRB051117B: optical observation
  64. GRB 051221A: MDM Optical Observations
  65. GRB 051221A: Detection at 251nm with Swift UVOT
  66. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  67. GRB 051221B: ROTSE-III Optical Limits
  68. GRB 051221B: TAROT optical limits
  69. GRB 051221B: Refined analysis of the Swift-BAT burst
  70. GRB 051221B: BOOTES optical observations.
  71. GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral
  72. Swift-BAT detection of a possible burst
  73. GRB 051221: Swift/UVOT upper limits
  74. GRB 051221: Improved astrometry of the IR counterpart
  75. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  76. GRB 051221: Swift detection of a bright short burst
  77. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  78. Swift detection of an RS CVn flare star
  79. GRB051211A: possible optical candidate
  80. GRB 051215: near-infrared observations
  81. GRB051215 - SDSS pre-burst observations
  82. GRB 051215: Swift detection of a possible burst
  83. GRB 051211B, optical observation
  84. GRB 051213: Swift-BAT detection of a burst
  85. GRB 051211A: Swift/UVOT upper limits
  86. GRB 051211B: Swift/UVOT upper limits
  87. GRB 051211A,optical observation
  88. GRB051211B: Liverpool Telescope observation
  89. GRB051211b: P60 Observations
  90. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  91. GRB 051210: Swift/UVOT upper limits
  92. GRB 051210: Magellan Imaging
  93. GRB 051211: TAROT optical limits
  94. GRB 051211B: a possible optical detection by TAROT
  95. GRB 051211: Swift XRT upper limit
  96. GRB 051211:IAC80 optical observations
  97. GRB 051210: SALT detection limit
  98. GRB 051210: BAT further refined analysis of the short burst
  99. GRB 051210: Swift XRT refined analysis
  100. GRB 051210: FRAM early limit

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