ToughSF brings up a point about Scholz and other past flybys of small stars. By his maths, a 52 kAU flyby of 0.15 M☉ (implicitly total) should acquire a Hill of 31.8 kAU from Sol. Even if the system didn't scrape Oort (Wikipedially considered 0.79 ly / 50 kAU), its L1 is well within limits; such as to bring down the sky.
Some Oorts from 31.8(ish) kAU would become comets with an orbit apoapsis 32 kAU and periapsis ≤ 1 AU. ... Their orbital period would be 16000.53/2 = 2,023,952 years.
Oorts from further out will get here later.
Now: for the Scholz binary itself, ToughSF's prior is wrong - and I'm not talking about the vagueness nor about whether the passing star's mass be 0.15 or 0.158 M☉. Scholz just didn't get this close. By the converter, 1.08 ly = 68.3 kAU. To that Hill, which has to be in the high 40s kAU, does Oort even extend? Beyond 0.79 ly / 50 kAU, all matter of other passing stars might have taken material away faster than the Sun can collect it. For instance: HD 7977 which is 1.07 M⊙ had already swooped by 2.788 Mya at 0.429 pc / 88.5 kAU; that one's Hill is low-40s kAU from us. I'll add that as a heavier star, it should have taken away more of our Oort than it bestowed to us. (h/t Phil Plait although he needs to learn the difference between a parsec and a lightyear.) So best not to speculate on Scholz. HD 7977's comets should have period 3 Mya, by the way, so have been to the Jupiter-range and gone by now.
... unless HD 7977's comets were perturbed by something else.
Unlike Scholz and HD 7977, UCAC4 237-008148 did come 0.8ish ly to us. The latest data I find says 0.259 parsecs so 53.4 kAU. Its mass is dangerous too: 0.82 M⊙. That L1 would cut deeper than 30 kAU, although not as far as the Hills torus 20 kAU. Worst of all: UCAC4 flew by 1.162 Mya. Some of these comets might be showing up, er... now.
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