Lunch talk on Apr. 24, 2020

Millions of periodic variables in the era of big data

Speaker:Xiaodian Chen (NAOC)

Venue:Video conference

Time:12:30 PM, Friday, April 24, 2020

Abstract:

The number of known periodic variables has grown rapidly in recent years. Here, we report about 800,000 periodic variables found in Wide-field Infrared Survey Explorer (WISE) the Zwicky Transient Facility (ZTF). Comparison with previously published catalogs shows that 80% of them are newly discovered or newly classified. The typical misclassification rate and period accuracy are about 1% and 98%, respectively. 80% of our variables are located at Galactic latitudes, |b| < 10. This large sample of Cepheids, RR Lyrae, Delta Scuti stars, and EW-type eclipsing binaries is helpful to investigate the Galaxy's disk structure and evolution with an improved completeness, areal coverage, and age resolution. Specifically, the northern warp and the disk's edge at distances of 15 to 20 kpc are better covered. Among rotational variables, RS CVN and BY Dra variables are well separated. Our knowledge of stellar chromospheric activity would benefit from the statistical analysis of these types of variables.

Report PPT:SWIFAR_Xiaodian Chen.pptx