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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"

20248 results found.

  1. GRB 060108: ISAS early observations and near IR upper limit
  2. GRB060108: P200 Ks Observations
  3. GRB 060108: early UKIRT K-band observations
  4. GRB 060109: Swift Detection of a long burst
  5. GRB 060108: VLT J-band observations
  6. GRB 060108: Mitsume optical observations
  7. GRB 060108: Swift/UVOT upper limits
  8. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  9. GRB060108: SDSS pre-burst observations
  10. GRB060108: Faulkes Telescope observation
  11. GRB060108, optical observation
  12. GRB 060108: Refined analysis of the Swift-BAT burst
  13. GRB060108: Swift detection of its 100th GRB
  14. GRB 060105: MDM Observation
  15. Konus-Wind observation of GRB 060105
  16. GRB 060105: ISAS observations and near IR upper limit
  17. GRB 060105: Swift/UVOT upper limits
  18. GRB 060105: Mitsume optical observations
  19. GRB 060105: BAT refined analysis
  20. GRB 060105: XRT refined analysis
  21. GRB060105: Suzaku-XIS and -HXD observation plan
  22. GRB060105, optical observation
  23. GRB060105: Swift detection of a bright long burst
  24. GRB 060102: MDM Observation
  25. Swift-BAT trigger 175653 is probably not a GRB
  26. GRB 051221B: Optical Observations with Kuiper 1.54m
  27. GRB 051227: optical observation
  28. GRB 051227: optical afterglow
  29. GRB 051227: Swift/UVOT Upper Limits (Possible U-band
  30. GRB 051227: Magellan r'-band Imaging/Astrometry
  31. GRB 051227: refined analysis of VLT images
  32. GRB 051227: P60 Observations
  33. GRB 051227: MDM Observation
  34. GRB 051227: R-band object in the XRT error circle
  35. GRB051227: SDSS pre-burst observations
  36. GRB 051227, optical observation
  37. GRB 051227: Swift detection of a burst
  38. GRB051117B: optical observation
  39. Konus-Wind observation of GRB 051221A
  40. GRB051221A: Suzaku WAM observation of the prompt emission
  41. GRB 051221A: MDM Optical Observations
  42. GRB 051221B: ROTSE-III Optical Limits
  43. GRB 051221B: TAROT optical limits
  44. GRB 051221A: RAPTOR Fading Counterpart Constraint
  45. GRB 051221B: BOOTES optical observations.
  46. Swift-BAT detection of a possible burst
  47. GRB 051221: Swift/UVOT upper limits
  48. GRB 051221: Improved astrometry of the IR counterpart
  49. GRB 051221: Swift detection of a bright short burst
  50. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  51. Swift detection of an RS CVn flare star
  52. GRB051211A: possible optical candidate
  53. GRB 051215: near-infrared observations
  54. GRB051215 - SDSS pre-burst observations
  55. GRB 051215: Swift detection of a possible burst
  56. GRB051105: optical observations
  57. GRB 051213: Swift-BAT refined analysis
  58. GRB 051211B, optical observation
  59. GRB 051211A: Swift/UVOT upper limits
  60. GRB 051211B: Swift/UVOT upper limits
  61. GRB 051211A,optical observation
  62. GRB051211B: Liverpool Telescope observation
  63. GRB051211b: P60 Observations
  64. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  65. GRB 051210: Swift/UVOT upper limits
  66. GRB 051210: Magellan Imaging
  67. GRB 051211: TAROT optical limits
  68. GRB 051211B: a possible optical detection by TAROT
  69. GRB 051211:IAC80 optical observations
  70. GRB 051210: Optical imaging from Las Campanas
  71. GRB 051210: SALT detection limit
  72. GRB 051210: FRAM early limit
  73. GRB051210: Swift UVOT Observation
  74. GRB 051210: Swift detection of a burst
  75. An extraordinary long burst on December 3 from SGR1806-20
  76. Possible resuming of the SGR 1806-20 activity
  77. GRB051117b: No Swift/UVOT Detection
  78. GRB 051117A: Swift/UVOT Detection of an Afterglow
  79. GRB051111: Suzaku WAM observation of the prompt emission
  80. GRB051008: Suzaku WAM observation of the prompt emission
  81. GRB 051109B: GAO 150cm telescope Optical limit
  82. GRB 051117B: R and I observations of possible host galaxy
  83. GRB 051117B,optical observation
  84. GRB 051117B: ROTSE-III Optical Limits
  85. GRB051114: results of the Swift-XRT observation
  86. GRB 051109B : Nainital upper limits
  87. GRB 051114: Radio Observations
  88. GRB050925: analysis of the XMM-Newton observation
  89. GRB 051111: Radio afterglow
  90. GRB051103: Radio Observations
  91. GRB051111: Swift/UVOT Observations
  92. GRB051111: XRT preliminary analysis
  93. GRB 051109A Optical Observations
  94. GRB 051111a: IR photometry
  95. GRB 051109B. Radio Observations
  96. GRB 051109A
  97. GRB051109A - radio observations
  98. Early RAPTOR measurements of GRB 051109a - the movie.
  99. GRB 051109B: ROTSE-III Optical Limits
  100. GRB 051109A: Swift-UVOT Observations

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