The phrase "a stellar group of" is correct and usable in written English.
It can be used to describe a highly impressive or outstanding collection of people or things, often in a positive context.
Example: "The conference featured a stellar group of speakers who shared their insights on innovation and technology."
Alternatives: "an exceptional team of" or "a remarkable collection of".
This was a stellar group of 3-year-olds".
The Gunga Din is a stellar group of veteran expressionists making carnival music for after the apocalypse.
He did not face a stellar group of opponents in the Delaware turf race, but he could not have won more easily.
"We feel incredibly excited and lucky that we will be working with such a stellar group of singers, friends, and musicians, without whose help this complicated and unconventional tour would never be possible".
They enlisted a stellar group of their friends to act in the film, among them Gwyneth Paltrow, Kevin Kline, Phoebe Cates, John C. Reilly, Jane Adams, Jennifer Beals, John Benjamin Hickey and Parker Posey.
The British army and the MRC had convened a stellar group of scientists and neurosurgeons, including J.Z. Young, Peter Medawar, Ernst Gutmann, Hugh Cairns and Herbert Seddon, to work on the challenges of neurological injury.
Supposedly it has raised just €1.25 million or so in total funding although exact figures were never announced, even though they assembled a stellar groups of backers who have much deeper pockets than that.
"It was a pretty stellar group of Americans," James Dobbins, a special envoy to crisis zones for the Clinton, Bush, and Obama Administrations, told me.
Astronomers using NASA's Spitzer Space Telescope have mapped a stellar group being picked clean of its planetary disks by O-stars.
Flux, a platform that lets the building industry design eco-friendly homes by drawing on big data to do a lot of the hard work, is coming out of stealth with $8 million in funding from a pretty stellar group of investors.
Whether a stellar group materializes as an association or a cluster seems to depend on the efficiency of star formation.
