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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"

45169 results found.

  1. GRB051103: optical observations
  2. GRB 051103, optical observations
  3. GRB051103: MASTER: OT limit and host galaxy candidates
  4. GRB051028: Swift-XRT refined analysis
  5. GRB 051105a, observation from Naini Tal and OSN
  6. GRB 051105A, 2nd epoch optical observations
  7. GRB 051105a: MDM Observations
  8. GRB 051105A: TNG optical observations
  9. GRB051105A: Swift/UVOT Observations
  10. GRB 051105A, radio observations
  11. GRB051103:_MASTER_optical_observations
  12. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  13. GRB 051105A, optical observations
  14. XRT observations of GRB 051105A
  15. GRB 051105: Swift-BAT improved refined analysis
  16. GRB 051105b: ART optical limits
  17. GRB051105B - A long GRB detected by INTEGRAL
  18. GRB 051105B (INTEGRAL 2701): Optical observation
  19. GRB 051105: Swift-BAT refined analysis
  20. GRB 051105: Optical limit
  21. GRB 051105: Swift detection of a short burst
  22. IBAS Alert 2700: Not a GRB
  23. GRB 051016B host spectroscopy and redshift
  24. GRB051016B: optical observation
  25. Recent GRB UBVRcIc field photometry
  26. Konus-Wind observation of GRB 051028
  27. GRB051028:MASTER correction and final results
  28. GRB 051022: RTT150 optical observations
  29. GRB 051021A: RTT150 optical observations
  30. GRB051028 SARA Observation
  31. GRB051028: optical observations
  32. GRB051028: Swift/UVOT upper limits
  33. GRB051028: confirmation of the afterglow
  34. GRB051028: WHT optical candidate
  35. GRB051028: Swift XRT Position
  36. GRB051028:MASTER observations
  37. GRB 051028 (=H3951): A GRB localized by HETE
  38. GRB051028:MASTER optical observations
  39. GRB 051022: XRT Refined Spectral and Temporal Analysis--Correction
  40. GRB051022: Swift XRT measurement of jet break
  41. SGR 1806-20: continued moderate activity seen with INTEGRAL
  42. GRB051021B: Swift/UVOT Upper limits
  43. GRB 051021, Optical Observations
  44. GRB 051022: XRT Refined Spectral and Temporal Analysis
  45. GRB 051022, refined optical astrometry
  46. Chandra Observations of GRB 051022
  47. GRB051012: Swift-XRT analysis
  48. GRB 051022 Chandra Observations scheduled
  49. GRB051021B: Swift XRT refined analysis
  50. GRB051021a: optical observations
  51. GRB 051022: WSRT Radio Detection
  52. GRB 051022, mm counterpart
  53. GRB051022: host galaxy redshift
  54. GRB 051022: Swift/UVOT Upper Limits
  55. GRB051022: Radio Counterpart
  56. GRB051022: IR observations
  57. GRB 051022: SOAR JKs Observations
  58. GRB051021A: Swift XRT refined analysis
  59. Konus-Wind observation of GRB 051022
  60. GRB051022: Optical Observations
  61. GRB 051022: Magellan NIR imaging
  62. GRB 051021: PROMPT RcIc Observations
  63. GRB051021b: Magellan IR Imaging
  64. GRB 051022: Spectral Analysis Indicates That The Spectrum Is Absorbed
  65. GRB 051021: Correction
  66. GRB 051022, J & K-band observation
  67. GRB 051021, SMARTS optical/IR observations
  68. GRB051022: Swift XRT Position
  69. GRB 051021: P200 Ks Observations
  70. IPN triangulation of GRB051022 (=H3950)
  71. GRB 051021: MDM Upper Limit
  72. GRB 051022 (=H3950): SXC Flight Localization is Valid
  73. GRB051021: Swift/UVOT Upper Limits
  74. GRB 051021B: Refined analysis of the Swift-BAT burst
  75. GRB 051022: SSO40 Optical Observations
  76. GRB051022,optical observation
  77. GRB 051022A: ROTSE-III Optical Limits
  78. GRB051022 (=H3590), A GRB Detected By HETE
  79. GRB 051022: Optical observations
  80. GRB 051021,optical observation
  81. GRB051021B: Swift XRT Position
  82. GRB 051021: SOAR NIR Observations
  83. GRB 051021B: Swift detection of a burst
  84. GRB051021: Swift XRT analysis
  85. GRB051021 (=H3947): Refined Analysis
  86. GRB 051021 : optical afterglow observation at Lulin
  87. GRB 051021: Optical observations
  88. GRB 051021: ROTSE-III Confirmation of Optical Counterpart
  89. GRB 051021: Optical observations and candidate afterglow
  90. GRB051021.63
  91. GRB051021.6: MASTER optical observation
  92. Swift-BAT trigger 160640 is not a real GRB
  93. GRB051021: A GRB Localized by HETE
  94. Swift-BAT trigger 160619 is not a GRB
  95. Swift-BAT triggered on a posible CR Shower or possible GRB
  96. GRB 050502b: Optical limit
  97. GRB 051016b: Optical limit
  98. Afterglow candidate of GRB 051016B observed at Lulin
  99. GRB 051016b: Gemini Near IR Observations
  100. GRB 051016A: Swift/UVOT upper limits

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