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A search for hot post-AGB stars in the IRAS Point Source Catalog.
In this paper a first step is made to search for hot post-AGB stars inthe IRAS Point Source Catalog. In order to find objects that evolved offthe AGB a longer time ago than post-AGB objects discussed in theliterature, objects that were not detected at 12 μm by IRAS wereselected, The selection yielded 15 objects, of which 12 have spectraltype B, and would appear to be efficient in finding hot objects.However, this result does not necessarily mean that these are oldevolved objects. Some stars are associated with dense galactic cirrusand are probably normal massive supergiants, and a number of stars aregood post-AGB candidates because of their galactic latitudes and theircool, extended infrared emission. The possibility remains that theseobjects are normal supergiants heating the local interstellar medium.Finally, three remaining objects appear to be genuine post-AGB(candidate) stars, as is attested by their spectral and photometricproperties. The main conclusion derived from modelling their spectralenergy distributions is that the objects evolved off the AGB about 1000years ago, significantly longer than what is found for other post-AGBstars. Emission lines have appeared in the spectrum of one of theseobjects, SAO 243756, over the last 20 years. SAO 243756 bears closeresemblance to other objects that have been proposed to have entered thePlanetary Nebula phase recently. Several aspects of the problem ofselecting post-AGB stars in general are discussed.
| Magnitudes and colors for 833 Northern and Southern stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1955AJ.....60...65E&db_key=AST
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| Сазвежђа: | Штит |
| Ректацензија: | 18h56m46.10s |
| Deклинација: | -14°51'27.6" |
| Apparent магнитуда: | 7.167 |
| Даљина: | 354.61 parsecs |
| Proper motion RA: | 8.4 |
| Proper motion Dec: | -0.2 |
| B-T magnitude: | 7.378 |
| V-T magnitude: | 7.185 |
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