Pardon my ignorance, but why are they looking at just that ONE specific ‘star’ or ‘planet?’
What’s the significance to us of something 4 billion miles away? Is it the center of another Solar System or something?
Also, why didn’t we put Hillary! on this craft? LOL!
This is bonus science. Its primary mission was Pluto.
The original mission was a fly by of Pluto. This object happened to be close to the trajectory of the probe so it was rerouted to do a fly by .
It was the most interesting thing they could steer it towards after the Pluto flyby.
I suspect none of the answers you received were really what you were looking for, unless you happened to check out how much NH learned about Pluto, and what the character of Pluto really is. Anything learned "after" Pluto is just a bonus...
But, if you have not, I suggest you study the Wikipedia article on Pluto. (That's certainly not the end all and be all of such information, but it's not a bad place for a casually interested person to start.) The info. about Pluto's orbit gets a bit tedious, so, you may want to skim it to get to the real "meat" about its composition and geology.
(Note that space out past Saturn is really BIG: Trying to visit more than one or two outer planets takes a long time. Among other things, we have to "hibernate" these craft a good part of the journey, and every time we have to wake 'em back up, at these distances and conditions, the odds of something going wrong increase.)
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Now, why should you be interested in an article about Pluto, a dwarf planet billions of miles away? Well, for one, it looks like Pluto may have a substantial ocean of liquid water. Pluto also has tholins - complex organic molecules. (The Wikipedia article only implies this by saying it appears tholins have over time been transferred from Pluto to its moon, Charon. But, other articles clear this up: Just do a web search for "Pluto + tholins).
The interesting thing about tholins is that when you add them to liquid water, both at room temperature or thereabouts, you get amino acids, heterocyclic organo-nitrogen compounds and other building blocks of life. This does not mean "life as we know it" -- for one thing said "ocean" on, or more accurately, "in" Pluto, may actually be a water + ammonia mix. But this is one more find of a LOT of water on or in some of these bodies*, and that is very interesting indeed. If nothing else, it is pretty incredible to me that a water "ocean" can exist at all on such a small body, so far away from the Sun.
* https://www.businessinsider.com/water-space-volume-planets-moons-2016-10