Theoretical expectations for clump red giants as distance indicators
نویسنده
چکیده
Variations of ∼ 0.4 mag are expected in the I-band absolute magnitude of red clump giants, M I , as a function of both stellar age and metallicity. This regardless of some potential theoretical uncertainties. Due to the quite large differences in mean ages and metallicities of clump stars among galaxies, systematic changes (also amounting up to ∼ 0.4 mag) come out in their M I . These numbers also indicate a distance to the LMC that is not necessarily “short”.
منابع مشابه
The Optical Gravitational Lensing Experiment. Red Clump Stars as a Distance Indicator
We present calibration of the mean I-band brightness of red clump stars on metallic-ity. Red clump stars were proposed to be a very attractive standard candle for distance determination. The calibration is based on 218 nearby red giant stars whose high quality spectra allowed to determine accurate individual metal abundances. High quality par-allaxes (σπ/π < 10%) and photometry of these very br...
متن کاملThe Optical Gravitational Lensing Experiment. Red Clump Stars as a Distance Indicator
We present relation of the mean I-band brightness of red clump stars on metallicity. Red clump stars were proposed to be a very attractive standard candle for distance determination. The calibration is based on 284 nearby red giant stars whose high quality spectra allowed to determine accurate individual metal abundances. High quality par-allaxes (σπ/π < 10%) and photometry of these very bright...
متن کاملThe Optical Gravitational Lensing Experiment: Red Clump Stars as a Distance Indicator.
We present relation of the mean I-band brightness of red clump stars on metallicity. Red clump stars were proposed to be a very attractive standard candle for distance determination. The calibration is based on 284 nearby red giant stars whose high-quality spectra made it possible to determine accurate individual metal abundances. High-quality parallaxes (sigmapi&solm0;pi<10%) and photometry of...
متن کاملK-Band Calibration of the Red Clump Luminosity
The average near-infrared (K-band) luminosity of 238 Hipparcos red clump giants is derived and then used to measure the distance to the Galactic center. These Hipparcos red clump giants have been previously employed as I-band standard candles. The advantage of the K-band is a decreased sensitivity to reddening, and perhaps also a reduced systematic dependence on metallicity. In order to investi...
متن کاملK-Band Red Clump Distance to the Large Magellanic Cloud
The Hipparcos I-band calibration of horizontal-branch red clump giants as standard candles has lead to controversial results for the distance to the Large Magellanic Cloud (LMC). In an attempt to properly ascertain the corrections for interstellar extinction and clump age and metallicity, we analyze new multiwavelength luminosity functions of the LMC red clump. Our photometry dataset in the K-b...
متن کامل