What is an "Infrasun"?

[Chip]

There's not much to go on here, but here goes: Back in 1948, a science writer (who also edited for the Sci-Fi journal Astounding,) wrote an article which I haven't read, titled "Paper Planets." In it, he proposed a theory of something called an "Infrasun."

Obviously the idea (whatever it was) didn't catch on. However, it was apparently intriguing enough that the noted painter Chesley Bonestell, (who did those wonderful prehistoric paintings for Life Magazine in the 50s, as well as imaginative spacescapes for Arthur Clark's book Beyond Jupiter,) created an oil painting of an "Infrasun" beyond Pluto as seen from a southwestern American desert.

It sure looks unusual. As far as I know the picture is not on the Internet. It is on page 195 of the book: The Art of Chesley Bonestell by Ron Miller and Frederick C. Durant III, with forward by Arthur Clark.

I'm not so sure where to post this. Science fiction? Probably, but its not a TV show or movie, and Bonestell did a lot of paintings that were serious pre-space age attempts to depict observed phenomenon up close. (Still among my favorites are his various views of Saturn from its moons. His views of Jupiter also remarkably foreshadow actual pictures taken later.) Anyway, "Infrasun" was some kind of article and apparently not a story, so my question is posted here in "Against the Mainstream."

Anybody know what an "infrasun" is?

[Kaptain K]

My guess would be "brown dwarf".

[Wiley]

The prefix "infra" means below or inferior. So literally infrasun is a "little star".

"Twinkle, twinkle, infrasun ..."

[Chip]

Nice replies. Thanks!

The painting depicts a moonlit desert landscape. (Bonestell was really good at that effect but also in the night sky, there's a bright tiny point of light among the stars, with a much larger yet softly luminous shell around it.

[Ilya]

The only thing I have to go on is an SF novella published in Soviet Union in 1951 called "Draconis Infrasun". The idea is of a "star" so barely above the fusion mass minimum that its surface temperature is only a few hundred K. Of course such "star" would be black as coal, and would radiate only in infrared, hence "Infrasun". Whether such thing is possible, I don't know. Every brown dwarf will eventually cool off to black; I don't think the Universe is old enough for this to have happened. When it does, some objects with the barest trickle of fusion in their centers might stand out.