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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"

21263 results found.

  1. GRB060111 : XRT refined analysis
  2. GRB 060111: ROTSE-III Optical Limits
  3. GRB 060111: Swift detection of a burst
  4. GRB 060110: Mitsume optical observations
  5. GRB 060108: z-band imaging from Gemini-North
  6. GRB 060110a: RAPTOR detection of early optical emission.
  7. GRB 060110: UKIRT K-band observations
  8. GRB 060110: IR Candidate Afterglow
  9. GRB060110, optical observation
  10. GRB 060110: Super-LOTIS observations
  11. GRB 060110: Correction
  12. GRB 050110: IR Observations
  13. GRB 060110: Swift-BAT detection of a burst
  14. GRB 060109: Swift/UVOT upper limits
  15. GRB060109, optical observation
  16. GRB 060108: ISAS early observations and near IR upper limit
  17. GRB060108: P200 Ks Observations
  18. GRB 060108: early UKIRT K-band observations
  19. GRB 060109: Swift Detection of a long burst
  20. GRB 060108: VLT J-band observations
  21. GRB 060108: Mitsume optical observations
  22. GRB 060108: Swift/UVOT upper limits
  23. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  24. GRB060108: SDSS pre-burst observations
  25. GRB060108: Faulkes Telescope observation
  26. GRB060108, optical observation
  27. GRB 060108: Refined analysis of the Swift-BAT burst
  28. GRB060108: Swift detection of its 100th GRB
  29. GRB 060105: MDM Observation
  30. Konus-Wind observation of GRB 060105
  31. GRB 060105: ISAS observations and near IR upper limit
  32. GRB 060105: Swift/UVOT upper limits
  33. GRB 060105: Mitsume optical observations
  34. GRB 060105: BAT refined analysis
  35. GRB 060105: XRT refined analysis
  36. GRB060105: Suzaku-XIS and -HXD observation plan
  37. GRB060105, optical observation
  38. GRB060105: Swift detection of a bright long burst
  39. GRB 060102: MDM Observation
  40. Swift-BAT trigger 175653 is probably not a GRB
  41. GRB 051221B: Optical Observations with Kuiper 1.54m
  42. GRB 051227: optical observation
  43. GRB 051227: optical afterglow
  44. GRB 051227: Swift/UVOT Upper Limits (Possible U-band
  45. GRB 051227: Magellan r'-band Imaging/Astrometry
  46. GRB 051227: refined analysis of VLT images
  47. GRB 051227: P60 Observations
  48. GRB 051227: MDM Observation
  49. GRB 051227: R-band object in the XRT error circle
  50. GRB051227: SDSS pre-burst observations
  51. GRB 051227, optical observation
  52. GRB 051227: Swift detection of a burst
  53. GRB051117B: optical observation
  54. Konus-Wind observation of GRB 051221A
  55. GRB051221A: Suzaku WAM observation of the prompt emission
  56. GRB 051221A: MDM Optical Observations
  57. GRB 051221B: ROTSE-III Optical Limits
  58. GRB 051221B: TAROT optical limits
  59. GRB 051221A: RAPTOR Fading Counterpart Constraint
  60. GRB 051221B: BOOTES optical observations.
  61. Swift-BAT detection of a possible burst
  62. GRB 051221: Swift/UVOT upper limits
  63. GRB 051221: Improved astrometry of the IR counterpart
  64. GRB 051221: Swift detection of a bright short burst
  65. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  66. Swift detection of an RS CVn flare star
  67. GRB051211A: possible optical candidate
  68. GRB 051215: near-infrared observations
  69. GRB051215 - SDSS pre-burst observations
  70. GRB 051215: Swift detection of a possible burst
  71. GRB051105: optical observations
  72. GRB 051213: Swift-BAT refined analysis
  73. GRB 051211B, optical observation
  74. GRB 051211A: Swift/UVOT upper limits
  75. GRB 051211B: Swift/UVOT upper limits
  76. GRB 051211A,optical observation
  77. GRB051211B: Liverpool Telescope observation
  78. GRB051211b: P60 Observations
  79. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  80. GRB 051210: Swift/UVOT upper limits
  81. GRB 051210: Magellan Imaging
  82. GRB 051211: TAROT optical limits
  83. GRB 051211B: a possible optical detection by TAROT
  84. GRB 051211:IAC80 optical observations
  85. GRB 051210: Optical imaging from Las Campanas
  86. GRB 051210: SALT detection limit
  87. GRB 051210: FRAM early limit
  88. GRB051210: Swift UVOT Observation
  89. GRB 051210: Swift detection of a burst
  90. An extraordinary long burst on December 3 from SGR1806-20
  91. Possible resuming of the SGR 1806-20 activity
  92. GRB051117b: No Swift/UVOT Detection
  93. GRB 051117A: Swift/UVOT Detection of an Afterglow
  94. GRB051111: Suzaku WAM observation of the prompt emission
  95. GRB051008: Suzaku WAM observation of the prompt emission
  96. GRB 051109B: GAO 150cm telescope Optical limit
  97. GRB 051117B: R and I observations of possible host galaxy
  98. GRB 051117B,optical observation
  99. GRB 051117B: ROTSE-III Optical Limits
  100. GRB051114: results of the Swift-XRT observation

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