We present observations of four bright stars observed with the AstroSat Soft X-ray Telescope (SXT). Visible light from bright stars like these can leak through the very thin filter in front of the CCD in the focal plane CCD camera of the SXT and thus making the extraction of X-ray events difficult. Here, we show how to extract the X-ray events without contamination by the visible light. The procedure applied to four bright stars here demonstrates how reliable X-ray information can be derived in such cases. The sample of bright stars studied here consists of two A spectral types (HIP 19265, HIP 88580), one G/K giant (Capella), and a nearby M-type dwarf (HIP 23309). No X-ray emission is observed from the A-type stars, as expected. X-ray spectra of Capella and HIP 23309 are derived and modeled here, and compared with the previous X-ray observations of these stars to show the reliability of the method used. We find that optical light can start to leak in the very soft energy bands below 0.5 keV for stars with \(V=8\) mag. In the process, we present the first X-ray spectrum of HIP 23309.

我们展示了使用 AstroSat 软 X 射线望远镜 (SXT) 观测到的四颗明亮恒星的观测结果。来自这些明亮恒星的可见光可以通过 SXT 焦平面 CCD 相机中 CCD 前面的非常薄的滤光片泄漏，从而使 X 射线事件的提取变得困难。在这里，我们展示了如何在不受可见光污染的情况下提取 X 射线事件。此处应用于四颗明亮恒星的程序展示了在这种情况下可以得到多么可靠的 X 射线信息。此处研究的亮星样本包括两个 A 光谱类型（HIP 19265、HIP 88580）、一个 G/K 巨星（Capella）和附近的 M 型矮星（HIP 23309）。正如预期的那样，没有观察到 A 型恒星的 X 射线发射。Capella 和 HIP 23309 的 X 射线光谱在此处导出和建模，并与之前对这些恒星的 X 射线观测进行比较，以显示所用方法的可靠性。我们发现光学光可以开始在低于 0.5 keV 的非常软的能带中泄漏，对于具有\(V=8\) mag。在此过程中，我们展示了 HIP 23309 的第一个 X 射线光谱。