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New absolute magnitude calibrations for WUrsa Majoris type binaries

✍ Scribed by Z. Eker; S. Bilir; E. Yaz; O. Demircan; M. Helvacı


Book ID
101698846
Publisher
John Wiley and Sons
Year
2009
Tongue
English
Weight
322 KB
Volume
330
Category
Article
ISSN
0004-6337

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✦ Synopsis


Parallaxes of W UMa stars in the Hipparcos catalogue have been analyzed. 31 W UMa stars, which have the most accurate parallaxes (σπ/π < 0.15) which are neither associated with a photometric tertiary nor with evidence of a visual companion, were selected for re-calibrating the Period-Luminosity-Color (PLC) relation of W UMa stars. Using the Lutz-Kelker (LK) bias corrected (most probable) parallaxes, periods (0.26 < P < 0.87, P in days), and colors (0.04 < (B -V )0 < 1.28) of the 31 selected W UMa, the PLC relation have been revised and re-calibrated. The difference between the old (revised but not bias corrected) and the new (LK bias corrected) relations are almost negligible in predicting the distances of W UMa stars up to about 100 pc. But, it increases and may become intolerable as distances of stars increase. Additionally, using (J -H)0 and (H -Ks)0 colors from 2MASS (Two Micron All Sky Survey) data, a PLC relation working with infrared data was derived. It can be used with infrared colors in the range -0.01 < (J -H)0 < 0.58, and -0.10 < (H -Ks)0 < 0.18. Despite of the fact that the 2MASS data refer to single epoch observations which are not guaranteed to be taken at maximum brightness of the W UMa stars, the established relation has been found surprisingly consistent and reliable in predicting LK corrected distances of W UMa stars.


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