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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"

28049 results found.

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

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