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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"

20363 results found.

  1. GRB 051227: R-band object in the XRT error circle
  2. GRB051227: SDSS pre-burst observations
  3. GRB 051227, optical observation
  4. GRB 051227: Swift detection of a burst
  5. GRB051117B: optical observation
  6. Konus-Wind observation of GRB 051221A
  7. GRB 051221A: MDM Optical Observations
  8. GRB 051221B: TAROT optical limits
  9. Swift-BAT detection of a possible burst
  10. GRB 051221: Swift/UVOT upper limits
  11. GRB 051221: Improved astrometry of the IR counterpart
  12. GRB 051221: Swift detection of a bright short burst
  13. Swift detection of an RS CVn flare star
  14. GRB051211A: possible optical candidate
  15. GRB 051215: near-infrared observations
  16. GRB051215 - SDSS pre-burst observations
  17. GRB 051215: Swift detection of a possible burst
  18. GRB 051211B, optical observation
  19. GRB 051211A: Swift/UVOT upper limits
  20. GRB 051211B: Swift/UVOT upper limits
  21. GRB 051211A,optical observation
  22. GRB051211B: Liverpool Telescope observation
  23. GRB051211b: P60 Observations
  24. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  25. GRB 051210: Swift/UVOT upper limits
  26. GRB 051210: Magellan Imaging
  27. GRB 051211: TAROT optical limits
  28. GRB 051211B: a possible optical detection by TAROT
  29. GRB 051211:IAC80 optical observations
  30. GRB 051210: SALT detection limit
  31. GRB 051210: Swift XRT refined analysis
  32. GRB 051210: FRAM early limit
  33. GRB051210: Swift UVOT Observation
  34. GRB 051210: Swift detection of a burst
  35. Swift XRT positions
  36. An extraordinary long burst on December 3 from SGR1806-20
  37. GRB051117B: Swift XRT refined analysis
  38. GRB051117b: No Swift/UVOT Detection
  39. GRB 051117A: Swift/UVOT Detection of an Afterglow
  40. GRB 051117B: R and I observations of possible host galaxy
  41. GRB 051117B,optical observation
  42. GRB051114: results of the Swift-XRT observation
  43. GRB 051109B : Nainital upper limits
  44. GRB 051114: Radio Observations
  45. GRB 051114: Swift-BAT refined analysis
  46. GRB050925: analysis of the XMM-Newton observation
  47. GRB 051111: Further spectroscopic analysis
  48. GRB 051111: Radio afterglow
  49. GRB051103: Radio Observations
  50. GRB 051109A Milagro GeV/TeV Observations
  51. GRB051111: Swift/UVOT Observations
  52. GRB051111: XRT preliminary analysis
  53. GRB 051109A Optical Observations
  54. GRB 051111a: IR photometry
  55. GRB 051103 Milagro GeV/TeV Observations
  56. GRB 051109B. Radio Observations
  57. GRB 051109A
  58. GRB051109A - radio observations
  59. GRB 051109A: Swift-UVOT Observations
  60. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  61. GRB051109B: no UVOT source detected
  62. GRB051109B: XRT position
  63. GRB 051109B: Super-LOTIS Observations
  64. GRB051105B: REM Optical observation
  65. GRB 051109: Rc and Ic observations
  66. GRB 051109a: IR Photometry and Astrometry
  67. GRB051109: Swift detection of a burst
  68. GRB 051109a: IR Detections
  69. GRB051105B: Swift/XRT upper limit
  70. GRB051105B: Swift/UVOT upper limit
  71. GRB051103: MASTER: OT limit and host galaxy candidates
  72. GRB 051105a, observation from Naini Tal and OSN
  73. GRB 051105a: MDM Observations
  74. GRB 051105A: TNG optical observations
  75. GRB051105A: Swift/UVOT Observations
  76. GRB 051105A, radio observations
  77. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  78. XRT observations of GRB 051105A
  79. GRB 051105: Swift detection of a short burst
  80. Recent GRB UBVRcIc field photometry
  81. GRB051028 SARA Observation
  82. GRB051028: Swift/UVOT upper limits
  83. GRB051028: Swift XRT Position
  84. GRB051028:MASTER observations
  85. GRB051022: Swift XRT measurement of jet break
  86. GRB051021B: Swift/UVOT Upper limits
  87. GRB 051021, Optical Observations
  88. GRB051012: Swift-XRT analysis
  89. GRB 051022, mm counterpart
  90. GRB 051022: Swift/UVOT Upper Limits
  91. GRB051022: Radio Counterpart
  92. GRB051022: IR observations
  93. GRB051021A: Swift XRT refined analysis
  94. Konus-Wind observation of GRB 051022
  95. GRB051022: Optical Observations
  96. GRB051021b: Magellan IR Imaging
  97. GRB 051022: Spectral Analysis Indicates That The Spectrum Is Absorbed
  98. GRB051022: Swift XRT Position
  99. GRB 051021: P200 Ks Observations
  100. GRB 051022 (=H3950): SXC Flight Localization is Valid

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