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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"

28046 results found.

  1. GRB 051109A: Swift-UVOT Observations
  2. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  3. GRB051109B: no UVOT source detected
  4. GRB051109B: XRT refined analysis
  5. GRB 051109B : Lulin Optical Observations
  6. GRB 051109A : Lulin BVRI Optical afterglow observation
  7. GRB051109A: further steepening in the X-ray light curve
  8. GRB051109A: XRT refined analysis
  9. GRB 051109B: Super-LOTIS Observations
  10. GRB051105B: REM Optical observation
  11. GRB 051109B: Swift detection of a burst
  12. GRB 051109: Rc and Ic observations
  13. GRB 051109: Swift-BAT refined analysis
  14. GRB 051109a: IR Photometry and Astrometry
  15. GRB051109: Swift detection of a burst
  16. GRB 051109a: IR Detections
  17. GRB051105B: Swift/XRT upper limit
  18. GRB051105B: Swift/UVOT upper limit
  19. GRB051103: MASTER: OT limit and host galaxy candidates
  20. GRB051028: Swift-XRT refined analysis
  21. GRB 051105a, observation from Naini Tal and OSN
  22. GRB 051105a: MDM Observations
  23. GRB 051105A: TNG optical observations
  24. GRB051105A: Swift/UVOT Observations
  25. GRB 051105A, radio observations
  26. GRB051103:_MASTER_optical_observations
  27. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  28. GRB 051105A, optical observations
  29. XRT observations of GRB 051105A
  30. GRB 051105b: ART optical limits
  31. GRB 051105B (INTEGRAL 2701): Optical observation
  32. GRB 051105: Swift detection of a short burst
  33. Recent GRB UBVRcIc field photometry
  34. GRB051028 SARA Observation
  35. GRB051028: optical observations
  36. GRB051028: Swift/UVOT upper limits
  37. GRB051028: Swift XRT Position
  38. GRB051028:MASTER observations
  39. GRB051021B: Swift/UVOT Upper limits
  40. GRB 051021, Optical Observations
  41. GRB 051022: XRT Refined Spectral and Temporal Analysis
  42. GRB051012: Swift-XRT analysis
  43. GRB051021B: Swift XRT refined analysis
  44. GRB 051022, mm counterpart
  45. GRB 051022: Swift/UVOT Upper Limits
  46. GRB051022: Radio Counterpart
  47. GRB051022: IR observations
  48. GRB051021A: Swift XRT refined analysis
  49. GRB051022: Optical Observations
  50. GRB051021b: Magellan IR Imaging
  51. GRB 051021, SMARTS optical/IR observations
  52. GRB051022: Swift XRT Position
  53. GRB 051021: P200 Ks Observations
  54. GRB 051022 (=H3950): SXC Flight Localization is Valid
  55. GRB051021: Swift/UVOT Upper Limits
  56. GRB 051021B: Refined analysis of the Swift-BAT burst
  57. GRB 051022: SSO40 Optical Observations
  58. GRB051022,optical observation
  59. GRB 051021,optical observation
  60. GRB 051021B: Swift detection of a burst
  61. GRB 051021 : optical afterglow observation at Lulin
  62. GRB 051021: Optical observations and candidate afterglow
  63. GRB051021.63
  64. GRB051021.6: MASTER optical observation
  65. GRB051021: A GRB Localized by HETE
  66. Swift-BAT triggered on a posible CR Shower or possible GRB
  67. GRB 051016b: Optical limit
  68. Afterglow candidate of GRB 051016B observed at Lulin
  69. GRB 051016A: Swift/UVOT upper limits
  70. GRB 051016B: refined analysis of the Swift/XRT data
  71. GRB 051016B: Swift/UVOT detection
  72. GRB 051016B,optical observation
  73. GRB 051016B : Optical follow-up at Lulin
  74. GRB 051016B: Refined analysis of the Swift-BAT burst
  75. GRB 051016B: Swift detection of a soft burst
  76. GRB 051016: Swift-BAT refined analysis
  77. GRB051016 XMM-Newton observation
  78. GRB051016: Swift XRT refined analysis.
  79. GRB 051016: PROMPT Observations
  80. GRB051016: Swift detection of a burst
  81. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  82. GRB 051012: Swift-BAT detection of burst yesterday
  83. Swift-BAT Trigger 159578 is a possible burst
  84. GRB 051006: Swift/UVOT Upper Limits
  85. GRB051008: optical candidate
  86. GRB 051008 - a low redshift low-luminosity burst?
  87. GRB051011: bright nebulae near error box
  88. GRB051011: MASTER optical observation
  89. GRB051008: Final refined analysis of the Swift-BAT burst
  90. GRB051008: Radio Observation
  91. GRB 051008, optical observations
  92. GRB 051008: early Swift XRT analysis
  93. GRB 051008: Swift UVOT Candidate
  94. GRB 051006: P60 Observations
  95. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  96. GRB 051006: optical observations at Sierra Nevada
  97. GRB051006: Refined analysis of the Swift-BAT burst
  98. GRB051006: Swift detection of a burst
  99. GRB 050906, summary of radio observations
  100. GRB051001: Swift UVOT Upper Limits

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