I think it’s safe to assume that any planet not in the Hoth ‘solar system’ would take years to reach on sublight engines
I think the official explanation is that the Falcon (and most ships) had a backup hyperdrive, designed only to get you (slowly) to an inhabited system for repairs.
My preferred explanation is that it’s a fairly dense area of space, such that systems are closer together than in our region, and that it still probably took several months to get to Bespin. This, of course, aligns with Luke needing more than a few days’ training with Yoda.
Well I don’t know how a hyperdrive is slow, but a hyperdrive is a hyperdrive.
And if Han has it, he would use it, in a situation like that.
He didn’t even try.
The only explanation for that, that there was no backup hyperdrive. Or he is stupid, but I would dismiss that probability.
Therefore he only had sublight engines.
Which made me do the math, and it turned out that it is possible to get to Bespin from the Hoth sytem in a couple of months, using only sublight engines.
I tried to calculate the least possible distance between 2 neighboring solar systems, based on our universe.
I was thinking about possible max. speed, to calculate time needed to cover that distance, but actually it is the fuel that limits max. speed, as you can accelerate in space until you reach lightspeed.
Also a reasonable accelaration rate is needed, that makes dogfight still possible.
I calculated that they can accelerate to 5 million km/h in 38 hours at max acceleration.
Yeah, that is a lot of fuel, but with no info about it, we don’t know how much fuel they burn. Since max speed depends on fuel, which can not be calculated, therefore 5 million km/h is an educated guesstimate, but is needed to create something to calculate with.
The outer limit of the Cuiper belt, which is considered the edge of our Solar system, is 50 AU from the sun.
This distance would be a bit more than 62 days with the calculated max, speed. Still there is acceleration and deceleration, but it is around 2 months.
Our sun is not the smallest possible yellow star, so for size of solar system calculation, it needs to be taken into account, that the size of the sun of the Hoth and Bespin system, that is still a yellow star, can be smaller.
Based on data, I think 40 AU system edge is reasonable, but of course suns could be even closer, but it is good enough for rough estimation.
So a 40 AU trip with 5 million km/h would take about 50 days. Double that and we have a 100 day trip between Hoth and Bespin.
I checked the Falcon, and it has everything to accomodate a long journey like this.
And it gives Luke enough time to train on Dagobah.