Abstract

H 3-75 is a medium-excitation planetary nebula with a binary central star consisting of a hot subdwarf with \(T_{\textrm{hot}}\sim 10^{5}\) K and a cool giant. We present the results of our photometric and spectroscopic observations obtained in 2020 and analyze data from the literature. The brightness of the cool component of the binary system has been measured in the \(VR_{C}I_{C}JHK\) bands. We have measured the relative intensities of emission lines in the spectrum of the planetary nebula H 3-75, estimated the extinction, and determined the gaseous envelope parameters. We have found the spectral type and luminosity class of the cool star to be K0 III and analyzed its spectrum. We have estimated the distance to the object (\(d\sim 3660\) pc) and the luminosities of the components of the binary system: \(L_{\textrm{cool}}\sim 50L_{\odot}\) and \(L_{\textrm{hot}}\sim 160L_{\odot}\). The hot subdwarf’s parameters \(T_{\textrm{hot}}\) and \(L_{\textrm{hot}}\) place the star on the cooling track of post-AGB stars.

中文翻译：

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H 3-75：双星中央恒星NSV 16624的行星状星云

摘要

H 3-75是中度激发的行星状星云，具有一个双星中央恒星，由具有\（T _ {\ textrm {hot}} \ sim 10 ^ {5} \） K的热亚矮星和一个凉爽的巨星组成。我们介绍了2020年获得的光度学和光谱学观测结果，并分析了来自文献的数据。已在\（VR_ {C} I_ {C} JHK \）频段中测量了二进制系统的冷组件的亮度。我们已经测量了行星状星云H 3-75光谱中发射线的相对强度，估计了消光并确定了气态包络参数。我们发现冷星的光谱类型和光度等级为K0 III，并对其光谱进行了分析。我们估计了到物体的距离（\（d \ sim 3660 \）pc）以及二进制系统组件的亮度：\（L _ {\ textrm {cool}} \ sim 50L _ {\ odot} \）和\（L _ {\ textrm {hot}} \ sim 160L _ {\ odot} \）。高温亚矮星的参数\（T _ {\ textrm {hot}} \）和\（L _ {\ textrm {hot}} \）将恒星置于AGB后恒星的冷却轨道上。