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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"

33846 results found.

  1. Early RAPTOR measurements of GRB 051109a - the movie.
  2. Konus-Wind observation of GRB 051109A
  3. GRB 051109B: Swift-BAT refined analysis
  4. GRB 051109B: ROTSE-III Optical Limits
  5. GRB 051109A: Swift-UVOT Observations
  6. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  7. GRB 051109B : Lulin Optical Observations
  8. GRB 051109A : Lulin BVRI Optical afterglow observation
  9. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  10. GRB051109B: XRT position
  11. GRB 051109B: Super-LOTIS Observations
  12. GRB 051109B Kiso optical follow-up observation
  13. GRB 051109B: Swift detection of a burst
  14. GRB 051109: HET Optical Spectrum and Absorption Redshift
  15. GRB 051109: PROMPT Detections
  16. GRB 051109: Rc and Ic observations
  17. GRB 051109: Swift-BAT refined analysis
  18. GRB 051109a: IR Photometry and Astrometry
  19. GRB 051109a: MDM Observations
  20. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  21. GRB 051109a: IR Detections
  22. GRB 051109: ROTSE-III Detection of Possible Counterpart
  23. GRB051105B: Swift/XRT upper limit
  24. GRB051105B: Swift/UVOT upper limit
  25. GRB051103: optical observations
  26. GRB 051103, optical observations
  27. GRB051103: MASTER: OT limit and host galaxy candidates
  28. GRB 051105a, observation from Naini Tal and OSN
  29. GRB 051105A, 2nd epoch optical observations
  30. GRB 051105a: MDM Observations
  31. GRB 051105A: TNG optical observations
  32. GRB051105A: Swift/UVOT Observations
  33. GRB 051105A, radio observations
  34. GRB051103:_MASTER_optical_observations
  35. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  36. GRB 051105A, optical observations
  37. XRT observations of GRB 051105A
  38. GRB 051105: Swift-BAT improved refined analysis
  39. GRB 051105b: ART optical limits
  40. GRB051105B - A long GRB detected by INTEGRAL
  41. GRB 051105B (INTEGRAL 2701): Optical observation
  42. GRB 051105: Swift-BAT refined analysis
  43. GRB 051105: Optical limit
  44. GRB 051105: Swift detection of a short burst
  45. IBAS Alert 2700: Not a GRB
  46. GRB 051016B host spectroscopy and redshift
  47. GRB051016B: optical observation
  48. Recent GRB UBVRcIc field photometry
  49. Konus-Wind observation of GRB 051028
  50. GRB051028:MASTER correction and final results
  51. GRB 051022: RTT150 optical observations
  52. GRB 051021A: RTT150 optical observations
  53. GRB051028 SARA Observation
  54. GRB051028: optical observations
  55. GRB051028: Swift/UVOT upper limits
  56. GRB051028: confirmation of the afterglow
  57. GRB051028: WHT optical candidate
  58. GRB051028: Swift XRT Position
  59. GRB051028:MASTER observations
  60. GRB 051028 (=H3951): A GRB localized by HETE
  61. GRB051028:MASTER optical observations
  62. GRB 051022: XRT Refined Spectral and Temporal Analysis--Correction
  63. GRB051022: Swift XRT measurement of jet break
  64. GRB051021B: Swift/UVOT Upper limits
  65. GRB 051021, Optical Observations
  66. GRB 051022: XRT Refined Spectral and Temporal Analysis
  67. GRB 051022, refined optical astrometry
  68. Chandra Observations of GRB 051022
  69. GRB 051022 Chandra Observations scheduled
  70. GRB051021a: optical observations
  71. GRB 051022: WSRT Radio Detection
  72. GRB 051022, mm counterpart
  73. GRB051022: host galaxy redshift
  74. GRB 051022: Swift/UVOT Upper Limits
  75. GRB051022: Radio Counterpart
  76. GRB 051022: SOAR JKs Observations
  77. Konus-Wind observation of GRB 051022
  78. GRB051022: Optical Observations
  79. GRB 051022: Magellan NIR imaging
  80. GRB 051021: PROMPT RcIc Observations
  81. GRB051021b: Magellan IR Imaging
  82. GRB 051022: Spectral Analysis Indicates That The Spectrum Is Absorbed
  83. GRB 051021: Correction
  84. GRB 051022, J & K-band observation
  85. GRB 051021, SMARTS optical/IR observations
  86. GRB 051021: P200 Ks Observations
  87. IPN triangulation of GRB051022 (=H3950)
  88. GRB 051021: MDM Upper Limit
  89. GRB 051022 (=H3950): SXC Flight Localization is Valid
  90. GRB051021: Swift/UVOT Upper Limits
  91. GRB 051021B: Refined analysis of the Swift-BAT burst
  92. GRB 051022: SSO40 Optical Observations
  93. GRB 051022A: ROTSE-III Optical Limits
  94. GRB051022 (=H3590), A GRB Detected By HETE
  95. GRB 051022: Optical observations
  96. GRB 051021,optical observation
  97. GRB051021B: Swift XRT Position
  98. GRB 051021: SOAR NIR Observations
  99. GRB 051021B: Swift detection of a burst
  100. GRB051021 (=H3947): Refined Analysis

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