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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"

26344 results found.

  1. GRB051109B: no UVOT source detected
  2. GRB051109B: XRT refined analysis
  3. GRB 051109B : Lulin Optical Observations
  4. GRB 051109A : Lulin BVRI Optical afterglow observation
  5. GRB051109A: further steepening in the X-ray light curve
  6. GRB051109A: XRT refined analysis
  7. GRB 051109B: Super-LOTIS Observations
  8. GRB051105B: REM Optical observation
  9. GRB 051109B: Swift detection of a burst
  10. GRB 051109: Rc and Ic observations
  11. GRB 051109: Swift-BAT refined analysis
  12. GRB 051109a: IR Photometry and Astrometry
  13. GRB051109: Swift detection of a burst
  14. GRB 051109a: IR Detections
  15. GRB051105B: Swift/XRT upper limit
  16. GRB051105B: Swift/UVOT upper limit
  17. GRB051103: MASTER: OT limit and host galaxy candidates
  18. GRB051028: Swift-XRT refined analysis
  19. GRB 051105a, observation from Naini Tal and OSN
  20. GRB 051105a: MDM Observations
  21. GRB 051105A: TNG optical observations
  22. GRB051105A: Swift/UVOT Observations
  23. GRB 051105A, radio observations
  24. GRB051103:_MASTER_optical_observations
  25. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  26. GRB 051105A, optical observations
  27. XRT observations of GRB 051105A
  28. GRB 051105b: ART optical limits
  29. GRB 051105B (INTEGRAL 2701): Optical observation
  30. GRB 051105: Swift detection of a short burst
  31. Recent GRB UBVRcIc field photometry
  32. GRB051028 SARA Observation
  33. GRB051028: optical observations
  34. GRB051028: Swift/UVOT upper limits
  35. GRB051028: Swift XRT Position
  36. GRB051028:MASTER observations
  37. GRB051021B: Swift/UVOT Upper limits
  38. GRB 051021, Optical Observations
  39. GRB 051022: XRT Refined Spectral and Temporal Analysis
  40. GRB051012: Swift-XRT analysis
  41. GRB051021B: Swift XRT refined analysis
  42. GRB 051022, mm counterpart
  43. GRB 051022: Swift/UVOT Upper Limits
  44. GRB051022: Radio Counterpart
  45. GRB051022: IR observations
  46. GRB051021A: Swift XRT refined analysis
  47. GRB051022: Optical Observations
  48. GRB051021b: Magellan IR Imaging
  49. GRB 051021, SMARTS optical/IR observations
  50. GRB051022: Swift XRT Position
  51. GRB 051021: P200 Ks Observations
  52. GRB 051022 (=H3950): SXC Flight Localization is Valid
  53. GRB051021: Swift/UVOT Upper Limits
  54. GRB 051021B: Refined analysis of the Swift-BAT burst
  55. GRB 051022: SSO40 Optical Observations
  56. GRB051022,optical observation
  57. GRB 051021,optical observation
  58. GRB 051021B: Swift detection of a burst
  59. GRB 051021 : optical afterglow observation at Lulin
  60. GRB 051021: Optical observations and candidate afterglow
  61. GRB051021.63
  62. GRB051021.6: MASTER optical observation
  63. GRB051021: A GRB Localized by HETE
  64. Swift-BAT triggered on a posible CR Shower or possible GRB
  65. GRB 051016b: Optical limit
  66. Afterglow candidate of GRB 051016B observed at Lulin
  67. GRB 051016A: Swift/UVOT upper limits
  68. GRB 051016B: refined analysis of the Swift/XRT data
  69. GRB 051016B: Swift/UVOT detection
  70. GRB 051016B,optical observation
  71. GRB 051016B : Optical follow-up at Lulin
  72. GRB 051016B: Refined analysis of the Swift-BAT burst
  73. GRB 051016B: Swift detection of a soft burst
  74. GRB 051016: Swift-BAT refined analysis
  75. GRB051016 XMM-Newton observation
  76. GRB051016: Swift XRT refined analysis.
  77. GRB 051016: PROMPT Observations
  78. GRB051016: Swift detection of a burst
  79. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  80. GRB 051012: Swift-BAT detection of burst yesterday
  81. Swift-BAT Trigger 159578 is a possible burst
  82. GRB 051006: Swift/UVOT Upper Limits
  83. GRB051008: optical candidate
  84. GRB 051008 - a low redshift low-luminosity burst?
  85. GRB051011: bright nebulae near error box
  86. GRB051011: MASTER optical observation
  87. GRB051008: Final refined analysis of the Swift-BAT burst
  88. GRB051008: Radio Observation
  89. GRB 051008, optical observations
  90. GRB 051008: early Swift XRT analysis
  91. GRB 051008: Swift UVOT Candidate
  92. GRB 051006: P60 Observations
  93. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  94. GRB 051006: optical observations at Sierra Nevada
  95. GRB051006: Refined analysis of the Swift-BAT burst
  96. GRB051006: Swift detection of a burst
  97. GRB 050906, summary of radio observations
  98. GRB051001: Swift UVOT Upper Limits
  99. GRB 050925: Second Epoch WSRT Radio Observations
  100. GRB 051001: I-band limit

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