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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"

28047 results found.

  1. GRB 051109B: Swift-BAT refined analysis
  2. GRB 051109A: Swift-UVOT Observations
  3. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  4. GRB051109B: no UVOT source detected
  5. GRB051109B: XRT refined analysis
  6. GRB 051109B : Lulin Optical Observations
  7. GRB 051109A : Lulin BVRI Optical afterglow observation
  8. GRB051109A: further steepening in the X-ray light curve
  9. GRB051109A: XRT refined analysis
  10. GRB 051109B: Super-LOTIS Observations
  11. GRB051105B: REM Optical observation
  12. GRB 051109B: Swift detection of a burst
  13. GRB 051109: Rc and Ic observations
  14. GRB 051109: Swift-BAT refined analysis
  15. GRB 051109a: IR Photometry and Astrometry
  16. GRB051109: Swift detection of a burst
  17. GRB 051109a: IR Detections
  18. GRB051105B: Swift/XRT upper limit
  19. GRB051105B: Swift/UVOT upper limit
  20. GRB051103: MASTER: OT limit and host galaxy candidates
  21. GRB051028: Swift-XRT refined analysis
  22. GRB 051105a, observation from Naini Tal and OSN
  23. GRB 051105a: MDM Observations
  24. GRB 051105A: TNG optical observations
  25. GRB051105A: Swift/UVOT Observations
  26. GRB 051105A, radio observations
  27. GRB051103:_MASTER_optical_observations
  28. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  29. GRB 051105A, optical observations
  30. XRT observations of GRB 051105A
  31. GRB 051105b: ART optical limits
  32. GRB 051105B (INTEGRAL 2701): Optical observation
  33. GRB 051105: Swift detection of a short burst
  34. Recent GRB UBVRcIc field photometry
  35. GRB051028 SARA Observation
  36. GRB051028: optical observations
  37. GRB051028: Swift/UVOT upper limits
  38. GRB051028: Swift XRT Position
  39. GRB051028:MASTER observations
  40. GRB051021B: Swift/UVOT Upper limits
  41. GRB 051021, Optical Observations
  42. GRB 051022: XRT Refined Spectral and Temporal Analysis
  43. GRB051012: Swift-XRT analysis
  44. GRB051021B: Swift XRT refined analysis
  45. GRB 051022, mm counterpart
  46. GRB 051022: Swift/UVOT Upper Limits
  47. GRB051022: Radio Counterpart
  48. GRB051022: IR observations
  49. GRB051021A: Swift XRT refined analysis
  50. GRB051022: Optical Observations
  51. GRB051021b: Magellan IR Imaging
  52. GRB 051021, SMARTS optical/IR observations
  53. GRB051022: Swift XRT Position
  54. GRB 051021: P200 Ks Observations
  55. GRB 051022 (=H3950): SXC Flight Localization is Valid
  56. GRB051021: Swift/UVOT Upper Limits
  57. GRB 051021B: Refined analysis of the Swift-BAT burst
  58. GRB 051022: SSO40 Optical Observations
  59. GRB051022,optical observation
  60. GRB 051021,optical observation
  61. GRB 051021B: Swift detection of a burst
  62. GRB 051021 : optical afterglow observation at Lulin
  63. GRB 051021: Optical observations and candidate afterglow
  64. GRB051021.63
  65. GRB051021.6: MASTER optical observation
  66. GRB051021: A GRB Localized by HETE
  67. Swift-BAT triggered on a posible CR Shower or possible GRB
  68. GRB 051016b: Optical limit
  69. Afterglow candidate of GRB 051016B observed at Lulin
  70. GRB 051016A: Swift/UVOT upper limits
  71. GRB 051016B: refined analysis of the Swift/XRT data
  72. GRB 051016B: Swift/UVOT detection
  73. GRB 051016B,optical observation
  74. GRB 051016B : Optical follow-up at Lulin
  75. GRB 051016B: Refined analysis of the Swift-BAT burst
  76. GRB 051016B: Swift detection of a soft burst
  77. GRB 051016: Swift-BAT refined analysis
  78. GRB051016 XMM-Newton observation
  79. GRB051016: Swift XRT refined analysis.
  80. GRB 051016: PROMPT Observations
  81. GRB051016: Swift detection of a burst
  82. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  83. GRB 051012: Swift-BAT detection of burst yesterday
  84. Swift-BAT Trigger 159578 is a possible burst
  85. GRB 051006: Swift/UVOT Upper Limits
  86. GRB051008: optical candidate
  87. GRB 051008 - a low redshift low-luminosity burst?
  88. GRB051011: bright nebulae near error box
  89. GRB051011: MASTER optical observation
  90. GRB051008: Final refined analysis of the Swift-BAT burst
  91. GRB051008: Radio Observation
  92. GRB 051008, optical observations
  93. GRB 051008: early Swift XRT analysis
  94. GRB 051008: Swift UVOT Candidate
  95. GRB 051006: P60 Observations
  96. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  97. GRB 051006: optical observations at Sierra Nevada
  98. GRB051006: Refined analysis of the Swift-BAT burst
  99. GRB051006: Swift detection of a burst
  100. GRB 050906, summary of radio observations

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