The study of the quiet Sun in gamma rays started over a decade ago, and rapidly gained a wide interest. Gamma rays from the quiet Sun are produced by Galactic Cosmic Rays (CRs) interacting with its surface (disk component) and with its photon field (spatially extended inverse-Compton component, IC). The latter component is maximum close to the Sun and it is above the background even at large angular distances, extending over the whole sky. First detected with EGRET, it is studied now with Fermi-LAT with high statistical significance. Observations of the IC component allow us to obtain information on CR electrons and positrons close to the Sun and in the heliosphere for the various periods of solar activity and polarity. They allow to learn about CR interactions and propagation in the stellar photosphere and heliosphere, and to understand the solar environment and its activity. Analyses of solar observations are usually model-driven. Hence advances in model calculations and constraints from precise CR measurements are timely and needed. Here we present our StellarICS code to compute the gamma-ray IC emission from the Sun and also from single stars. The code is publicly available and it is extensively used by the scientific community to analyze Fermi-LAT data. It has been used by the Fermi-LAT collaboration to produce the solar models released with the FSSC Fermi Tools. Our modeling provides the basis for analyzing and interpreting high-energy data of the Sun and of stars. After presenting examples of updated solar IC models in the Fermi-LAT energy range that account for the various CR measurements, we extend the models to keV, MeV, and TeV energies for predictions for present and future possible telescopes such as AMEGO, GECCO, an e-ASTROGAM-like instrument, HAWC, LHAASO, SWGO, and X-ray telescopes. We also present predictions for some of the closest and most luminous stars.

在伽马射线中对安静太阳的研究始于十多年前，并迅速引起了广泛的兴趣。来自安静太阳的伽马射线是由银河宇宙射线 (CRs) 与其表面（圆盘分量）和光子场（空间扩展的逆康普顿分量，IC）相互作用产生的。后一个分量最接近太阳，即使在大角度距离处，它也高于背景，延伸到整个天空。首先用EGRET检测，现在用Fermi-LAT进行研究，具有很高的统计学意义。对 IC 组件的观察使我们能够获得太阳附近和日光层中太阳活动和极性的各个时期的 CR 电子和正电子的信息。它们允许了解恒星光球层和日球层中的 CR 相互作用和传播，并了解太阳环境及其活动。太阳观测的分析通常是模型驱动的。因此，模型计算的进步和精确 CR 测量的约束是及时和需要的。在这里，我们展示了我们的 StellarICS 代码来计算来自太阳和单颗恒星的伽马射线 IC 发射。该代码是公开的，被科学界广泛用于分析 Fermi-LAT 数据。Fermi-LAT 合作使用它来制作与 FSSC Fermi Tools 一起发布的太阳模型。我们的模型为分析和解释太阳和恒星的高能数据提供了基础。在展示了解释各种 CR 测量的 Fermi-LAT 能量范围内更新的太阳能 IC 模型的示例之后，我们将模型扩展到 keV、MeV、和 TeV 能量，用于预测当前和未来可能的望远镜，例如 AMEGO、GECCO、类似 e-ASTROGAM 的仪器、HAWC、LHAASO、SWGO 和 X 射线望远镜。我们还对一些最接近和最明亮的恒星进行了预测。