Classic sci fi story of plasma beings in star living super fast & evolving past man in a few months

Having a brain fart re the title of this story.

Observation ship investigating aspects of some star see what appears to be purposeful intelligence in energy fluctuations and try to communicate. This jump starts energy beings evolution and in a few weeks/months of this observation and communication they evolve past man.

What is that story?

Dragon's Egg - Wikipedia ?

Terr beat me to it, but it sounds like you have Robert L. Forward’s Dragon’s Egg in mind – only that story is about being made of nuclear matter living on the surface of a neutron star, not plasma beings on a regular star (there ARE stories about such creatures, but I don’t know of any with the plot you give). Foirward reasoned that, since nuclear reactions (which governed the creatures on his neutron star) were faster than chemical reactions, the neutron beings would have an accelerated time scale, compared to us.
There was also a pretty unnecessary sequel, Starquake. But Dragon’s Egg is top-notch hard SF from 1982.

Seconding the recommendation, it’s a great book.

Thanks!

I think Forward borrowed the idea from Sturgeon’s “Microcosmic God” - a scientist creates a tiny race of sentient beings with a tremendously accelerated time frame, and forces them to create new inventions in what for them are decades or even millennia.