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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"

15987 results found.

  1. GRB050925: analysis of the XMM-Newton observation
  2. GRB051109A optical observations
  3. GRB 051111: Radio afterglow
  4. GRB 051111: AEOS optical observations
  5. GRB051111: Swift/UVOT Observations
  6. GRB 051111A : R-band temporal decay index based on Lulin
  7. GRB051111: XRT preliminary analysis
  8. GRB 051109A Optical Observations
  9. GRB 051111A : Lulin BVRI multi band afterglow observation
  10. GRB 051111A: KAIT optical observations
  11. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  12. GRB 051109A
  13. GRB 051105a: GETS optical limit
  14. GRB 051109A: KAIT optical observations
  15. Early RAPTOR measurements of GRB 051109a - the movie.
  16. GRB 051109B: ROTSE-III Optical Limits
  17. GRB 051109A: Swift-UVOT Observations
  18. GRB 051109B : Lulin Optical Observations
  19. GRB 051109A : Lulin BVRI Optical afterglow observation
  20. GRB051109A: XRT refined analysis
  21. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  22. GRB 051109B Kiso optical follow-up observation
  23. GRB051105B: REM Optical observation
  24. GRB 051109: HET Optical Spectrum and Absorption Redshift
  25. GRB 051109: Rc and Ic observations
  26. GRB 051109a: IR Photometry and Astrometry
  27. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  28. GRB051105B: Swift/XRT upper limit
  29. GRB051103: optical observations
  30. GRB 051103, optical observations
  31. GRB051103: MASTER: OT limit and host galaxy candidates
  32. GRB051028: Swift-XRT refined analysis
  33. GRB 051105a, observation from Naini Tal and OSN
  34. GRB 051105A, 2nd epoch optical observations
  35. GRB 051105A: TNG optical observations
  36. GRB051105A: Swift/UVOT Observations
  37. GRB 051105A, optical observations
  38. GRB 051105b: ART optical limits
  39. GRB 051105B (INTEGRAL 2701): Optical observation
  40. GRB 051105: Optical limit
  41. GRB 051016B host spectroscopy and redshift
  42. GRB051016B: optical observation
  43. Recent GRB UBVRcIc field photometry
  44. GRB 051022: RTT150 optical observations
  45. GRB 051021A: RTT150 optical observations
  46. GRB051028: optical observations
  47. GRB051028: confirmation of the afterglow
  48. GRB051028: WHT optical candidate
  49. GRB 051028 (=H3951): A GRB localized by HETE
  50. GRB051028:MASTER optical observations
  51. GRB 051022: XRT Refined Spectral and Temporal Analysis--Correction
  52. GRB 051021, Optical Observations
  53. GRB 051022: XRT Refined Spectral and Temporal Analysis
  54. GRB 051022, refined optical astrometry
  55. GRB051021a: optical observations
  56. GRB051021A: Swift XRT refined analysis
  57. GRB051022: Optical Observations
  58. GRB 051022: Spectral Analysis Indicates That The Spectrum Is Absorbed
  59. GRB 051021, SMARTS optical/IR observations
  60. GRB 051022 (=H3950): SXC Flight Localization is Valid
  61. GRB051021: Swift/UVOT Upper Limits
  62. GRB 051022: SSO40 Optical Observations
  63. GRB051022,optical observation
  64. GRB 051022A: ROTSE-III Optical Limits
  65. GRB051022 (=H3590), A GRB Detected By HETE
  66. GRB 051022: Optical observations
  67. GRB 051021,optical observation
  68. GRB051021: Swift XRT analysis
  69. GRB051021 (=H3947): Refined Analysis
  70. GRB 051021 : optical afterglow observation at Lulin
  71. GRB 051021: Optical observations
  72. GRB 051021: ROTSE-III Confirmation of Optical Counterpart
  73. GRB 051021: Optical observations and candidate afterglow
  74. GRB051021.6: MASTER optical observation
  75. GRB051021: A GRB Localized by HETE
  76. GRB 050502b: Optical limit
  77. GRB 051016b: Optical limit
  78. GRB 051016b: Gemini Near IR Observations
  79. GRB 051016B: Swift/UVOT detection
  80. GRB 051016B,optical observation
  81. GRB 051016B : Optical follow-up at Lulin
  82. GRB 051016: LCO optical and near-IR imaging
  83. GRB051006: optical observations
  84. GRB050805A: Rc optical observations
  85. GRB051008: optical candidate
  86. GRB051011: MASTER optical observation
  87. GRB051008: optical observation
  88. GRB 051008, optical observations
  89. GRB 051006: XRT refined analysis
  90. GRB 051006: optical observations at Sierra Nevada
  91. GRB051001: Swift UVOT Upper Limits
  92. GRB 051001, optical observations at Mt. John
  93. GRB 051001: ROTSE-III Optical Limits
  94. GRB050908: optical observations
  95. GRB050922C: optical observation
  96. GRB050922B: optical limit
  97. GRB 050922C: further VLT observations
  98. GRB050922C: UVES/VLT high resolution spectroscopy
  99. GRB050922C - Swift UVOT preliminary analysis
  100. GRB 050922C: break in the lightcurve

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