The nature of the dust around R Coronae Borealis stars - Isolated amorphous carbon or graphite fractals

Journal Article · Fri Feb 01 00:00:00 EST 1991 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169658· OSTI ID:5933609

Hecht, J H ^[1]

---

1. Aerospace Corp., Los Angeles, CA (USA)

Wright (1989) has proposed that the R CrB phenomenon is caused by the occurrence of graphite fractal grains, each composed of numerous, less than 15-nm-radius graphite spheres. It is shown that both the observational data and models of dust formation are more in accord with an earlier model by Hecht et al. (1984): that the R CrB type dust is composed of isolated small (less than 100-nm-radius) glassy or amorphous carbon grains. It cannot be ruled out that a significant number of fractal grains exist, provided that they have dielectric properties different from bulk graphite and closer to amorphous carbon, and that the individual grains in the fractals are below 1 nm in size. However, the existence of such fractal grains around R CrB stars might be ruled out by the lack of a 2400-A feature in the interstellar extinction curve. 30 refs.

• OSTI ID: 5933609
• Journal Information: Astrophysical Journal; (USA), Vol. 367; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ERUPTIVE VARIABLE STARS
COSMIC DUST
STAR MODELS
AMORPHOUS STATE
CARBON
CRYSTAL GROWTH
DIELECTRIC PROPERTIES
FRACTALS
GRAIN SIZE
GRAPHITE
INTERSTELLAR SPACE
CRYSTAL STRUCTURE
DUSTS
ELECTRICAL PROPERTIES
ELEMENTAL MINERALS
ELEMENTS
MATHEMATICAL MODELS
MICROSTRUCTURE
MINERALS
NONMETALS
PHYSICAL PROPERTIES
SIZE
SPACE
STARS
VARIABLE STARS
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources