Hypergiants are the largest stars possible. While most of them are either red or blue, a rare few are yellow. Which raises some intriguing questions about what would happen if  a Kryptonian or Daxamite ever encountered one. If the ultra-solar radiation that empowers Superman is only emitted by yellow main sequence stars, all well and good. I'm not sure what that would mean in this context. Perhaps Superman's body (or Supergirls, or Mon-Els) would store yellow main sequence star ultra-solar wavelength radiation like an organic battery in such cases. However, what if ultra-solar radiation is specific to all yellow suns, not just main sequence ones? To my knowledge, this question hasn't been explored in the comics. Superman (Supergirl, Mon-El, etc) haven't taken a trip out to Eta Bootis, a yellow subgiant; to Beta Draconis, a yellow giant, or Capella, a relatively close yellow giant; or Delta Cephei, a variable yellow supergiant; or at the most massive end of possible stellar mass and diameter, yellow hypergiants like Rho Cassiopeiae, R Puppis, HD 197821, IRAS 17163-3907, V382 Carinae, and several others. It should be noted that these stars are comparatively rare, due to their massive size- if placed at the centre of our solar system, these stars would extend all the way out to Neptune's orbit. Consequently, however, they're very short lived, lasting only several ten-million years compared to smaller stars. They're also variables, which means they radiate discontinuous amounts of heat and light. And when they blow up, it's with the force of  a supernova, leaving  a neutron star or black hole behind.

Let's assume that yellow hypergiants do radiate ultra-solar radiation too. The scale of such activity would probably overload Kryptonian or Daxamite physiologies, although both species have enhanced abilities under blue or white stars, and the equivalent of ultra-solar radiation gives superpowers to those born under yellow suns. Red or green suns deprive Kryptonians or Daxamites of their abilities (unless they're taking Brainiac 5's thirtieth century anti-lead serum). Therefore, it might be the case that encountering a yellow hypergiant's abundance of ultra-solar radiation would either immobilise red solar planetary inhabitants or cause cellular apoptosis, as was the case in Grant Morrison's All Star Superman.  Their bodies would be unable to properly metabolise it if administered on that scale. Which might provide a useful possibility for a spacebourne or space-capable Superman or LSH supervillain...

Source: en.wikipedia.org/wiki/Yellow_hypergiant