Bibcode
García-Hernández, D. A.; Kameswara Rao, N.; Lambert, David L.
Referencia bibliográfica
The Astrophysical Journal Letters, Volume 759, Issue 1, article id. L21, 6pp, (2012).
Fecha de publicación:
11
2012
Número de citas
15
Número de citas referidas
13
Descripción
We search high-resolution and high-quality VLT/UVES optical spectra of
the hot R Coronae Borealis star DY Cen for electronic transitions of the
C60 molecule and diffuse interstellar bands (DIBs). We report
the non-detection of the strongest C60 electronic transitions
(e.g., those at ~3760, 3980, and 4024 Å). The absence of
C60 absorption bands may support recent laboratory results,
which show that the ~7.0, 8.5, 17.4, and 18.8 μm emission features
seen in DY Cen—and other similar objects with
polycyclic-aromatic-hydrocarbon-like dominated IR spectra—are
attributable to proto-fullerenes or fullerene precursors rather than to
C60. DIBs toward DY Cen are normal for its reddening; the
only exception is the DIB at 6284 Å (possibly also the 7223
Å DIB) which is found to be unusually strong. We also report the
detection of a new broad (FWHM ~ 2 Å) and unidentified feature
centered at ~4000 Å. We suggest that this new band may be related
to the circumstellar proto-fullerenes seen at infrared wavelengths.
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