منابع مشابه
Terrestrial Zone Debris Disk Candidates in H and Χ Persei
We analyze 8 sources with strong mid-infrared excesses in the 13 Myr-old double cluster h and χ Persei. New optical spectra and broadband SEDs (0.36-8 μm) are consistent with cluster membership. We show that material with T∼300-400 K and Ld/L⋆ ∼10 -10 produces the excesses in these sources. Optically-thick blackbody disk models including those with large inner holes do not match the observed SE...
متن کاملTerrestrial Zone Debris Disk Candidates in H & Χ Persei
We analyze 8 sources with strong mid-infrared excesses in the 13 Myr-old double cluster h & χ Persei. New optical spectra and broadband SEDs (0.36-8 μm) are consistent with cluster membership. We show that material with T∼300-400 K and Ld/L⋆ ∼10 -10 produces the excesses in these sources. Optically-thick blackbody disk models including those with large inner holes do not match the observed SEDs...
متن کاملThe atmospheric parameters and chemical composition of early B-type giants in h and χ Persei
Atmospheric parameters and surface chemical compositions are presented for eight stars, classified as B1 or B2 but with a range of luminosity classes, in the northern double cluster h and χ Persei. Echelle spectroscopy (covering the wavelength region 3900 to 4700 Å) and grating spectroscopy (of the Balmer, Hγ and Hβ lines) were analysed using non-LTE synthetic spectra based on LTE line-blankete...
متن کاملThe Rise and Fall of Debris Disks: MIPS Observations of h and χ Persei and the Evolution of Mid-IR Emission from Planet Formation
We describe Spitzer/MIPS observations of the double cluster, h and χ Persei, covering a ∼ 0.6 square-degree area surrounding the cores of both clusters. The data are combined with IRAC and 2MASS data to investigate ∼ 616 sources from 1.25-24 μm. We use the long-baseline Ks-[24] color to identify two populations with IR excess indicative of circumstellar material: Be stars with 24 μm excess from...
متن کاملDense H-Free Graphs are Almost (χ(H)-1)-Partite
By using the Szemerédi Regularity Lemma [10], Alon and Sudakov [1] recently extended the classical Andrásfai-Erdős-Sós theorem [2] to cover general graphs. We prove, without using the Regularity Lemma, that the following stronger statement is true. Given any (r+1)-partite graph H whose smallest part has t vertices, there exists a constant C such that for any given ε > 0 and sufficiently large n...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1921
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/81.5.400