UBVy photometry of cool stars

We present high-precision photometry, high- and medium-resolution spectroscopy for a sample of 32 stars likely to be the optical counterparts of X-ray sources serendipitously...本研究针对32颗疑似为偶然发现的X射线源（X-ray sources）光学对应体（optical counterparts）的恒星样本，提供了高精度测光（photometry）与高、中分辨率光谱学观测数据。