EF Cha : Warm Dust Orbiting a Nearby 10 Myr Old Star

Content Provider	Semantic Scholar
Author	Rhee, Joseph H. Song, Inseok Zuckerman, Ben
Copyright Year	2008
Abstract	Most Vega-like stars have far-infrared excess (60μm or longward in IRAS, ISO, or Spitzer MIPS bands) and contain cold dust (.150K) analogous to the Sun’s Kuiper-Belt region. However, dust in a region more akin to our asteroid belt and thus relevant to the terrestrial planet building process is warm and produces excess emission in mid-infrared wavelengths. By cross-correlating Hipparcos dwarfs with the MSX catalog, we found that EF Cha, a member of the recently identified, ∼10Myr old, “Cha-Near” Moving Group, possesses prominent mid-infrared excess. N-band spectroscopy reveals a strong emission feature characterized by a mixture of small, warm, amorphous and possibly crystalline silicate grains. Survival time of warm dust grains around this A9 star is . 10 yrs, much less than the age of the star. Thus, grains in this extra-solar terrestrial planetary zone must be of ”second generation” and not a remnant of primodial dust and are suggestive of substantial planet formation activity. Such second generation warm excess occurs around & 4% of the stars in nearby young stellar associations. Subject headings: circumstellar matter — infrared: stars — planetary systems: protoplanetary disks — stars: individual (EF Cha)
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://arxiv.org/pdf/0706.1265v1.pdf
Alternate Webpage(s)	http://arxiv.org/pdf/0706.1265v2.pdf
Language	English
Access Restriction	Open
Subject Keyword	Bands Dust Racing 2D Dwarfism Entity Framework GUCY2C protein, human Isoproterenol Medical Subject Headings Mental association Offset binary Planetary scanner Remnant Second Generation Multiplex Plus Silicates Stars, Celestial Stellar (payment network) TCFL5 gene Terrestrial television YARS wt Allele aluminum magnesium silicate wavelength
Content Type	Text
Resource Type	Article