This #TESStuesday, I'm closing a tab with a mysterious SIMBAD search for HD 47874. Here's the amplitude spectrum for TESS Sectors 6 & 7. It appears to be a (blended?) eclipsing binary (hence the dense, low-frequency comb) that's also a high-order δ Scuti pulsator.
simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+47874
@mekonto I think of the fundamental frequency of δ Sct pulsators as going up to about 20-25 cycles/day. The ~regular spacing around 18-23-28 c/d suggests to me that those aren't fundamental, either.
Forced to guess, I'd say the peak around 12 c/d might be the radial fundamental mode. Hence my hunch is "higher-order", though to be fair the "higher-order" overtones might only be radial orders of 2-4.
@warrickball BTW why do you think is high order? The frequency range is pretty normal for dSct isn't it?