Fullerenes and fullerene-related molecules have been proposed as explanations for unidentified astronomical features such as the intense UV absorption band at 217 nm and the enigmatic diffuse interstellar bands (DIBs), In order to shed light on the a long-standing DIB’s problem, we search high-resolution and high-quality VLT/UVES optical spectra of the hot R Coronae Borealis (RCB) star DY Cen for electronic transitions of the neutral C60 fullerene molecule and DIBs. We report the non-detection of the strongest C60 electronic transitions (e.g., those at ∼376, 398, and 402 nm). DIBs towards DY Cen are normal for its reddening; the only exception is the DIB at 628 nm (possibly also the 722 nm DIB) that is found to be unusually strong. We also report the detection of a new broad (FWHM∼2 Å) and unidentified feature centered at∼400 nm. The non detection of neutral C60 in the high-quality VLT/UVES DY Cen’s spectrum may support recent experimental work, showing that the∼7.0, 8.5, 17.4, and 18.8 micron IR features seen in sources with polycyclic aromatic hydrocarbon (PAH)-like dominated spectra have to attributed to proto-fullerenes rather than to neutral C60. In addition, the new 400 nm DIB reported here (possibly also the carriers of the classical 628 nm and 722 nm DIBs) may be related to fullerene precursors; an organic compound containing pentagonal rings. These pentagonal carbon rings are usually present in hydrogenated amorphous carbon (HAC) nanoparticles and nanotubes, suggesting that they may be intimately related with the formation process of fullerenes.
Advertised on
References
The Astrophysical Journal Letters, 2012, 759, L21
It may interest you
-
Massive stars, those over ten times heavier than our Sun, are the conduits of most elements of the periodic table and drive the morphological and chemical makeup of their host galaxies. Yet the origin of the most luminous and hottest stars among them, called 'blue supergiants', has been debated for many decades. Blue supergiants are strange stars. First, they are observed in large numbers, despite conventional stellar physics expecting them to live only briefly. Second, they are typically found alone, despite most massive stars being born with companions. Third, the majority of them harbourAdvertised on
-
The magnetic field in the solar chromosphere plays a key role in the heating of the outer solar atmosphere and in the build-up and sudden release of energy in solar flares. However, uncovering the magnetic field vector in the solar chromosphere is a difficult task because the magnetic field leaves its fingerprints in the very faint polarization of the light, which is far from easy to measure and interpret. We analyse the spectropolarimetric observations obtained with the Chromospheric Layer Spectropolarimeter on board a sounding rocket. This suborbital space experiment observed the nearAdvertised on
-
It is well known that fullerenes – big, complex, and highly resistant carbon molecules with potential applications in nanotechnology – are mostly seen in planetary nebulae (PNe); old dying stars with progenitor masses similar to our Sun. Fullerenes, like C60 and C70, have been detected in PNe whose infrared (IR) spectra are dominated by broad unidentified IR (UIR) plateau emissions. The identification of the chemical species (structure and composition) responsible for such UIR emission widely present in the Universe is a mystery in astrochemistry; although they are believed to be carbon-richAdvertised on