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 کاملLINEAR PULSATION CHARACTERISTICS OF MIRA VARIABLE STARS
The linear adiabatic pulsation-periods of Mira variable stars have been derived. Approximately 2701[1]models were calculated for M = 0.7 MΘ to 2 MΘ stars with radii from 180 RΘ to 340 RΘ and luminosities from 2800 LΘ to 10,000 LΘ. The chemical composition of all models is (X,Z) = (0.7,0.02). From the result of this study, linear relations on Luminosity-Period-Mass relationship and luminosity-pe...
متن کاملA Quest for PMS candidate stars at low metallicity: Variable HAe/Be and Be stars in the Small Magellanic Cloud
We report the discovery of 5 new Herbig Ae/Be candidate stars in the Small Magellanic Cloud in addition to the 2 reported in Beaulieu et al. (2001). We discuss these 7 HAeBe candidate stars in terms of (1) their irregular photometric variability, (2) their near infrared emission, (3) their Hα emission and (4) their spectral type. One star has the typical photometric behaviour that is observed o...
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ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 1987
ISSN: 0252-9211
DOI: 10.1017/s0252921100116690