Help me with an adjective ...

Elucidates... shines a light / makes something clear ?

Teehee crafting no ...

You're not reviewing Torchy, Torchy The Battery Boy are you Grannyknot!

"Illuminating " if it sheds light surely. Luminous is something quite different.
"Incisive", "exhaustive" might do the job too.

Dazzling? Glaring?

Did the writing have certain "incandescent" quality to it?

I'm often incandescent, but usually with rage!

But does the text give off light or illuminate the subject?

gracesgran now I'm back with luminous in that case! Giving off light.

I'm another one who always thought 'coruscating' meant scathing or withering! You live and learn on GN!

jalima I suppose it would be a compliment to be described as having a coruscating wit.
Like you I had always thought it meant scathing.
I shall use it at the next opportunity

coruscating: to give off or reflect light in bright beams or flashes : sparkle. 2 : to be brilliant or showy in technique or style.

well, well, well!!

'on it' not just 'on'

I agree that you illuminate something when you shine a light on but luminous means giving off a light - like watches you can see in the dark; they had luminous hands and numbers.

Depending on what it illuminates you could use 'clarifies', 'elucidates' or 'reveals'

and I thought that 'coruscating' meant scathing and ultra-critical .....

back to the drawing board dictionary

and I meant as in the luminosity of stars .....

swanny thanks for looking out for me , but I've the hide of a rhinoceros!

Thanks everyone, I've got there now...and I've learnt stuff.

... as in throws a spotlight ...

Spotlights

What section of the population is the book aimed at? Knowing that might help with the adjective you're searching for. Is it fact or fiction?

My mantra is always try to keep it simple

Is it a book on astronomy?

I like 'luminescent' too

Careful roses - Grannyknot is the reviewer.

I think it just means that it 'shines' ie. is a brilliant book! Book reviewers are often pretentious, particularly if they are either Will Self or Martin Amis.

Luminiferous is the same, that really shines a light out at something, not that the light is being shone in on the subject. The author would be the luminiferous one. Nice word though.

'Perhaps something'