Questions about habitable zones, star luminosity, etc.

[con quesa]

In the interest of finally pinning down the exact orbital parameters of Arzhanø's orbit around its sun, and thus the length of its year, I want to calculate the distance from the sun that the planet would have to be to be roughly Earth-like.

I've always imagined that Arzhanø's sun is a little bit cooler and oranger than Earth's sun, but also that Arzhanø is somewhat of a warmer, wetter world than Earth, although still with (small, perhaps seasonal) icecaps at the poles. Details of the atmosphere, arrangement of landmasses, etc. that I'm basically not thinking thinking about (it's still fundamentally a fantasy sort of setting, even if the physics is more or less real-world) matter a lot for exactly what sorts of climate can happen even at a given distance from the sun, but I figure that aiming for an average global temperature of around 15 C is reasonable. And I want the length of the year to be somewhat shorter than that of Earth, although not really significantly shorter. So it's a question of calculating what (somewhat less than solar) luminosity of a sun will induce a habitable-zone orbit that is somewhat shorter than that of Earth, and apply rigorous numbers to these.

Unfortunately, my understanding of astronomy is a bit out of depth, and I'm not sure exactly what math I need to do to work this out. I figure this is something that lots of people have also had to think about, so I thought I'd punt my question to the board.

[2+3 clusivity]

Is your main concern the length of the year? If so, you could probably 'magic' away a lot of calculations via the speed of the orbit.

What type of star are you thinking of; what type of atmosphere; tectonic activity?

[Hallow XIII]

Stop right there, Geoff made a site for this!