We have collected almost all HdC, RCB and EHe stars up to date to investigate their infrared properties, in particular, their radiation mechanisms in the infrared, using the observational data from 2MASS, WISE and IRAS missions. Because HdC stars, RCB stars and EHe stars all belong to the category of extremely hydrogen-deficient stars and they definitely have some evolutionary connections.

It is found from this paper that all RCB stars have infrared excesse in the wavelength region from the near infrared to the far infrared covered by 2MASS, WISE and IRAS due to dust while almost all HdC stars and EHe stars have no or little infrared excess.

From 2MASS, WISE and IRAS two-color diagrams, it is also found that the majority of these three kinds of stars are around the power law distributions in the near infrared possibly indicative of their infrared radiations from the warm dust in the disk-like envelope. It is also found that in the mid- and far infrared regions some stars are around the power law distribution perhaps due to dust from disk-like envelope while some stars are around the blackbody distribution maybe due to the cold and extended nebulosity nearby.

我们收集了迄今为止几乎所有的 HdC、RCB 和 EHe 恒星，以研究它们的红外特性，特别是它们在红外线中的辐射机制，使用来自 2MASS、WISE 和 IRAS 任务的观测数据。因为HdC星、RCB星和EHe星都属于极度缺氢星的范畴，肯定有一些演化上的联系。

从该论文中发现，所有RCB星在2MASS、WISE和IRAS覆盖的近红外到远红外波长范围内都有红外过剩，而几乎所有的HdC星和EHe星都没有或几乎没有红外过剩。

从2MASS、WISE和IRAS的双色图还发现，这三种恒星中的大多数都在近红外的幂律分布附近，这可能表明它们的红外辐射来自盘状包层中的暖尘埃. 还发现，在中远红外区域，一些恒星在幂律分布附近，可能是由于盘状包层中的尘埃，而一些恒星在黑体分布附近，可能是由于附近的冷和扩展星云。