That depends on where you start and how much mass you want to take there. There are two many variables to make a guess. In general, because matter-antimatter conversion to energy results in a huge amount of energy (assuming that the antimatter is used in a matter-antimatter drive of some sort), it wouldn't take much.
4.37 years.
None that are known. There may be a roughly Earth-sized planet in orbit around Alpha Centauri B, but this planet, if it exists, would be far too hot to support life.
4.3 light years===========================Sorry. "Light year" is an answer to "how far", not "how long".Alpha Centauri is about 4.4 light years away from our solar system and everything in it,which means that it takes AC's light about 4.3 years to get here.
It's called Proxima Centauri. It's the dimmest of three stars all orbiting each other about 4.3 light years from us. Visually, we see the whole group as a single object, called "Alpha Centauri" ... a name that doesn't really mean anything except "brightest star in the constellation Centaurus". It's located quite far down in the southern sky, and it's never visible to anyone located farther north than about 29° north latitude ... roughly the line through San Antonio TX and Daytona Beach FL.
It takes about 4.37 years for a radio transmission to travel from Earth to Alpha Centauri (the nearest star system) and another 4.37 years for the signal to travel back. This means a total round-trip communication time of around 8.74 years.
That would be "Alpha Centauri". The distance is about 4.4 light-years.
The two objects most likely to be 4 light years apart would be two stars in our closest neighboring star system, Alpha Centauri. This system consists of three stars: Alpha Centauri A, Alpha Centauri B, and Proxima Centauri.
There will be hundred's. The closest would be Alpha Centauri A
4.37 years.
The sun of course! But if you mean beyond that, it would be Alpha Centauri
None that are known. There may be a roughly Earth-sized planet in orbit around Alpha Centauri B, but this planet, if it exists, would be far too hot to support life.
That's actually an easy calculation, if you state the problem correctly. Alpha Centauri is about 4.5 light years away. There are 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day, and 365.24 days in a year. Multiply all those numbers together to find out how many light-seconds it is to Alpha Centauri. The Moon is about 1.5 light seconds away, so divide by that to get the ratio.
Assuming that you start from earth, travelling that slowly to Alpha Centauri would take quite a bit of time. Alpha Centauri's about 4.367 light years away, which means at the suggested speed of 70,000 kilometers per hour, it would take you 673.26 centuries to get there. You definitely want to go much faster to get there.
The nearest star to Earth is Proxima Centauri, which is part of the Alpha Centauri star system. Proxima Centauri is located approximately 4.24 light years away from Earth.
First of all, there has never yet been any such thing known to earth as a starship. If an object left Cape Canaveral at 1/2 the speed of light, and maintained a straight-line course toward the place where Alpha Centauri would be when it got there, it would reach Alpha Centauri after the clock on the launch-pad had ticked off 8.8 years.
4.3 light years===========================Sorry. "Light year" is an answer to "how far", not "how long".Alpha Centauri is about 4.4 light years away from our solar system and everything in it,which means that it takes AC's light about 4.3 years to get here.
ANSWER:With the Sun being the first, Proxima Centauri is the next closest at 4.22 light years away in the Alpha Centauri star system. See the related link for more information.