The ASAS-SN catalogue of variable stars – VII. Contact binaries are different above and below the Kraft break
The ASAS-SN catalogue of variable stars – VII. Contact binaries are different above and below the Kraft break
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DOI：
10.1093/mnras/staa518
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发表时间：
2019-11
影响因子：
4.8
通讯作者：
T. Jayasinghe;K. Stanek;C. Kochanek;B. Shappee;M. Pinsonneault;T. Holoien;T. Thompson;J. Prieto
中科院分区：
文献类型：
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作者：
T. Jayasinghe;K. Stanek;C. Kochanek;B. Shappee;M. Pinsonneault;T. Holoien;T. Thompson;J. Prieto
我们利用超新星全天自动巡天 (ASAN-SN)V 波段全天光变曲线以及来自 Gaia、2MASS、AllWISE、LAMOST、GALAH、狂欢，和 远地点。 EW周期-光度关系在$\rm \log (\it P/{\rm d})\,{\simeq }\,{\rm -0.30}$处有一个彻底的断裂，将较长周期的早期型EW双星与较短周期的晚期型系统分开。这两个总体在周期和有效温度的空间中更加清晰地分开，$T_{\rm eff}=6710\,{\rm K}-1760\,{\rm K}\, \log (P/0.5\,{\rm d})$。早型和晚型 EW 双星的 Teff 随轨道周期变化的趋势相反。在较长时期内，早期类型的电子战双星系统温度较低，而晚期类型的系统则较热。我们推导了晚型和早型 EW 双星的 WJK、V、Gaia DR2 G、J、H、Ks 和 W1 波段的周期-光度关系，这些双星按周期和有效温度以及单独的周期分开。接触双星的二分法几乎肯定与克拉夫特断裂以及包层结构、风和角动量损失的相关变化有关。
We characterize ${\sim } 71\, 200$ W Ursae Majoris (UMa) type (EW) contact binaries, including ${\sim } 12\, 600$ new discoveries, using All-Sky Automated Survey for SuperNovae (ASAN-SN)V-band all-sky light curves along with archival data from Gaia, 2MASS, AllWISE, LAMOST, GALAH, RAVE, and APOGEE. There is a clean break in the EW period–luminosity relation at $\rm \log (\it P/{\rm d})\,{\simeq }\,{\rm -0.30}$, separating the longer period, early-type EW binaries from the shorter period, late-type systems. The two populations are even more cleanly separated in the space of period and effective temperature, by $T_{\rm eff}=6710\,{\rm K}-1760\,{\rm K}\, \log (P/0.5\,{\rm d})$. Early-type and late-type EW binaries follow opposite trends in Teff with orbital period. For longer periods, early-type EW binaries are cooler, while late-type systems are hotter. We derive period–luminosity relationships in the WJK, V, Gaia DR2 G, J, H, Ks, and W1 bands for the late-type and early-type EW binaries separated by both period and effective temperature, and by period alone. The dichotomy of contact binaries is almost certainly related to the Kraft break and the related changes in envelope structure, winds, and angular momentum loss.