Using the Hα line EW, we found 447 spectra with emission above continuum for a total of 316 stars (178 eclipsing binaries). We calculated their equivalent widths (EWs) of their Hα, Hβ, Hγ, Hδ and Caii H lines. We found 15,955 spectra for 11,469 stars (including 5398 eclipsing binaries). We cross-matched a total of 105,287 periodic variable stars from several photometric surveys and databases (CSS, LINEAR, Kepler, a recently updated eclipsing star catalogue, ASAS, NSVS, some part of SuperWASP survey, variable stars from the Tsinghua University-NAOC Transient Survey, and other objects from some new references) with four million stellar spectra published in the LAMOST data release 2 (DR2). The LAMOST spectral survey provides a rich databases for studying stellar spectroscopic properties and chromospheric activity. Jiang, Linyan Li, Zhongmu Zhang, Yong Hou, Yonghui Wang, Yuefei Cao, Zihuang Zhang, Liyun Lu, Hongpeng Han, Xianming L. (author)Ĭhromospheric activity of periodic variable stars (including eclipsing binaries) observed in DR2 LAMOST stellar spectral survey Some 15 per cent of these beams show that observed regular pattern, with a spacing between the peaks of the order of 105 h -1 -150 h -1 Mpc, but most pencil-beams show peaks in the redshift distribution without periodicity, so we may conclude that, even within a cellular universe, periodicity is not a common phenomenon. Narrow and deep, magnitude-limited, pencil-beam surveys through these structures are simulated. Galaxies, whose luminosities are selected from a Schechter luminosity function, are placed randomly within the walls of this cellular model. Nature 343, 726) showing a striking, nearly periodic, galaxy redshift distribution in a narrow pencil-beam survey, is explained within the Voronoi cellular model of clustering of galaxies. The recent result by Broadhurst et al., (1990. International Nuclear Information System (INIS) Quasi- periodicity in deep redshift surveys
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