Researchers just found the smallest galaxy ever.

"This map of stars in the vicinity of the identified object Ursa Major III/UNIONS 1 in two-dimensional space, with the contours showing the central location of a stellar overdensity. This may merely be the last remnants of a globular cluster, but it could also be the smallest dwarf galaxy ever discovered." (BigThink/ Astronomers just found the smallest galaxy ever)

The galaxy Ursa Major III/UNIONS 1 has a record. It is the smallest known galaxy. Its stellar mass is just 16 times of the Sun. The data of the new dwarf galaxy includes interesting details. Having only about 16 solar masses worth of stars within it, in total.

"It has an extremely low in metallicity, with a heavy element abundance of just ~0.6% of what’s found in the Sun. It is consistent with being composed exclusively of extremely old stars: stars more than 11 billion years old. "(BigThink/ Astronomers just found the smallest galaxy ever)

And that makes it an interesting object. The low stellar mass means that there are only small stars. The low metal density can mean that something blew metals away from that area. Or the Ursa Major III/UNIONS 1 formed when rogue stars started to orbit some kind of mass center. 

The Ursa Major III/UNIONS 1 follows the common rule of dwarf galaxies. Those objects have certain common things. The two most dominating are this: 

"They have very small numbers of stars within them." (BigThink/ Astronomers just found the smallest galaxy ever)

"And the stars that are present likely formed all at once, long ago, so that the brightest, most massive ones among them have died, leaving only the faintest, lowest-mass ones behind. "(BigThink/ Astronomers just found the smallest galaxy ever)

But the Ursa Major III/UNIONS 1 is a common dwarf galaxy. The common details about those things are this: 

Dwarf galaxies are, small, low in mass, contain very few numbers of stars, overall, but are dominated largely by dark matter. Many of those stars are old. And that makes dwarf galaxies interesting. Less than 1% of galaxies are like Milky Way. The most common galaxies are small. 

The number of old stars could be explained by annealing or energy flow from other stars being lower than in Milky Way-type large galaxies. That means supernovas and other effects like star wind don't turn stars so hot in dwarf galaxies. So they use their hydrogen slower and more evenly than in large galaxies. 

There is also the possibility that some massive object like a galaxy or quasar hovers gas and dust away from that galaxy. Then those stars collect new hydrogen or light material clouds around them. So, they are old stars in young nebula. 

And another interesting thing is that. This small galaxy must have some kind of gravity center. Or some other mass center that forces stars to orbit it. That thing can be the stellar mass black hole. Another thing that can cause the effect is some kind of energy- a particle beam that travels through the center of that star system. In that case, the invisible energy beam acts like a thermal pump. 

That thing makes the energy or quantum fields travel to one point. And that forces stars to orbit that point. The dwarf galaxies tell tales about the gravity and the history of the universe. The stars in that galaxy are very old. The galaxy is dominated by dark matter. The other thing is that. The galaxy has no heavy elements. 

Or there are much less heavy elements than in the Sun. That causes the idea that. Could that galaxy be the union of remnants of some other galaxies? Or is it formed because stars that escaped from their galaxies turned to orbit some mass center? There are always stars that escape from their galaxies. And they can form the dwarf galaxy. Or were heavy elements destroyed for some other reasons? 

By the way, some SETI researchers suggest that alien supercivilizations could exist in those dwarf galaxies. They include the oldest stars in the universe. So oldest stars can have the oldest planets. Logically thinking. The oldest civilizations can be on the oldest planetary systems. But that is only guessing. 

https://bigthink.com/starts-with-a-bang/astronomers-smallest-galaxy-ever/