Given this sobering result, it's fairly clear that we need to start looking for alternative forms of propulsion if we're ever going to reach the stars on the timescale of a human lifespan.
Two popular technologies that may be able to accomplish this have been explored in some detail. The first are solar sails, which are massive sail-like structures extended in space over many kilometers, which capture the momentum of photons emitted from our own sun to generate acceleration. The second is fusion energy, a form of energy which is known to power our sun, and, as far as we know, all the other stars in the universe.
Fusion typically involves light elements (for example, Hydrogen) being raised to incredibly high temperatures, typically many millions of degrees. When these light nuclei collide, they are able to form new heavier elements and release vast amounts of energy in the process.
To date, our technology has not been able to reach what's known as 'break-even' fusion, where more energy is output from the fusion reactor than was put in to start the reaction. However, there are numerous high profile, and quite a few low profile, fusion research groups across the world focusing a large amount of time and resources into making this a reality. Many believe it is just a matter of a few short decades, perhaps less, until this is done.