Discovery of variability in the 'non-variable' hydrogen-deficient carbon stars
نویسندگان
چکیده
منابع مشابه
Line-blanketed model atmospheres for R Coronae Borealis stars and hydrogen-deficient carbon stars
We have constructed line-blanketed model atmospheres for the hydrogen-deficient and carbon-rich R Coronae Borealis (RCrB) stars, as well as for the similar hydrogendeficient carbon (HdC) stars and the cool extreme helium (EHe) stars. Improved continuum opacities have been used together with realistic line absorption data for atomic andmolecular transitions. The observed dereddened fluxes of R C...
متن کاملDiscovery and Classification of Variable Stars
This thesis investigates the classification of variable stars and the discovery of interesting behaviour in some of them. A secondary aim was to attempt to do this without astronomical expertise (domain knowledge). The data comes from the Macho dataset which consists of time series observations of the red and blue magnitudes of about 60 million stars, each observed approximately every night. Th...
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 کاملOn the formation of hydrogen-deficient post-AGB stars
We present an evolutionary sequence of a low mass star from the Asymptotic Giant Branch (AGB) through its postAGB stage, during which its surface chemical composition changes from hydrogen-rich to strongly hydrogen-deficient as consequence of a very late thermal pulse, following the socalled born-again scenario. The internal structure and abundance changes during this pulse are computed with a ...
متن کاملDiscovery of Extreme Carbon Stars in the Large Magellanic Cloud
Using Spitzer IRAC and MIPS observations of the Large Magellanic Cloud, we have identified 13 objects that have extremely red mid-IR colors. Follow-up Spitzer IRS observations of seven of these sources reveal varying amounts of SiC and C2H2 absorption as well as the presence of a broad MgS feature in at least two cases, indicating that these are extreme carbon stars. Preliminary estimates find ...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1988
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/233.1.209