What emits the least radiation when hot?

What element with a high vapor point the emits to least light or radiation when heated to its vapor pressure point in a vacuum? 


Ideally I would like to know in 0 gravity and 0 pressure which elements can be get the hottest around the sun before the vapor pressure point is reached and/or emit the least black body radiation when hot. 


<https://space.stackexchange.com/questions/35486/shielding-capability-of-liquid-metals>




Technically, a smooth or molten, unoxidized metal surface (regardless of chemistry) makes a good candidate. [This thesis from Auburn University](https://www.google.com/url?sa=t&source=web&rct=j&url=https://etd.auburn.edu/bitstream/handle/10415/1395/TEODORESCU_GEORGE_46.pdf%3Fsequence%3D1&ved=2ahUKEwjW7cCwwM3hAhVLMawKHVYYClsQFjAKegQIBBAB&usg=AOvVaw0vaTPfk2IEPTbU45_qR4GW) reports the emissivities of both oxidized and unoxidized metals at temperatures typically encountered in industrial processes; note the low values for all the unoxidized metals studied in the IR range where most radiation is given off.


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