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Chemical composition of evolved stars of high galactic latitude
We have carried out abundance analysis for a sample of high galacticlatitude supergiants in search of evolved stars.We find that HD 27381 has atmospheric parameters and an abundancepatternvery similar to that of the post-AGB star HD 107369.HD 10285 and HD 25291 are moderately metal-poor andshow the influence of mixing that has brought the productsof NeNa cycle to the surface.The high galactic latitude B supergiant HD 137569 shows selectivedepletion of refractory elements normally seen in post-AGB stars.We find that the high velocity B typestar HD 172324 shows moderate deficiency of Fe group elements butthe CNO abundances are verysimilar to that of disk B supergiants. The observed variations inthe radial velocities, transient appearance of emission componentsin hydrogen line profiles and doublingof O I lines at 7774 Å support the possibility of this star beinga pulsating variable or a binary star.
| SAO stars with infrared excess in the IRAS Point Source Catalog
We have undertaken a search for SAO stars with infrared excess in theIRAS Point Source Catalog. In contrast to previous searches, the entireIRAS (12)-(25)-(60) color-color diagram was used. This selection yieldeda sample of 462 stars, of which a significant number are stars withcircumstellar material. The stars selected can be identified aspre-main-sequence stars, Be stars, protoplanetary systems, post-AGBstars, etc. A number of objects are (visual) binary stars.Characteristic temperatures and IR excesses are calculated and theirrelations to spectral type are investigated.
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| Takýmyýldýz: | Kucuk Ayi |
| Sað Açýklýk: | 17h10m20.75s |
| Yükselim: | +84°35'55.6" |
| Görünürdeki Parlaklýk: | 7.241 |
| Uzaklýk: | 161.29 parsek |
| özdevim Sað Açýklýk: | 28.9 |
| özdevim Yükselim: | -20.6 |
| B-T magnitude: | 8.544 |
| V-T magnitude: | 7.349 |
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