VCE physics has a number of core components and "optional studies". Core subjects are like motion...optional are like electronics/nuclear physics. Well it did when back in 2007 (as an Adult).
Unfortunately Astronomy/Astrophysics is a limited field and it only undertaken as an option by schools that have expertise in that area...aka a school that has a teacher suited for this.
Very difficult to find a school offering VCE astronomy as an option subject. This is probably a year 11 unit 1&2 option
but is available.
If not available at your local school...then maybe distance education? The other alternative is to apply for a school that runs said curriculum...like
Melbourne high.
That said...a good physics background would not hamper them from studying astrophysics at uni.