Lack of objects between heliopause and Oort cloud? If we take a look at a logarithmic scale of the Solar System, there appears to be a large gap between the heliopause and the Oort cloud:


Why is that? There are some objects in the gap, but why are most of the Oort cloud objects in one area? Shouldn't it also fill the large gap in the picture just as much?
There may be Sednoids there.

Sednoids are a hypothetical class of "inner Oort Cloud objects" named after their prototype, Sedna. Sedna's aphelion is ~936 AU, bringing it close to the inner boundary of the Oort Cloud. Sednoids may have aphelions ranging from about 100 AU to 1,000 AU.

The problem is, only two Sednoids have beet detected to date, 90377 Sedna and 2012 VP113. Brown et al. 2004) suggested that ~500 may be detectable; surveys simply haven't tracked objects in that area.

Why are Sendnoids where they are? Three ideas have but put forth:


A planet at ~70 AU scattered these objects into elliptical orbits.
A close pass by a nearby star.
Interactions with other stars in the Sun's original cluster.


These objects would fill in the space between the Kuiper Belt/scattered disc and the Oort Cloud itself.