I'm always writing about planets or moons so, I'm going to write about stars (suns) instead. We often hear about two stars system called a binary system. This is when two stars with similar mass orbit a common point of mass, known as Barycentre. If the stars are of different mass, then it looks like one star is orbiting the other. Like when the Moon goes around the Earth. Though we say the Moon orbits around the Earth, the case is that they both are orbiting a centre of mass.
Let's talk about Aquarii 99 which is in the constellation of Aquarius and is visible to the naked eye. Aquarii 99 does one better than a binary star system, as it has a triple star system. It's not just Aquarii 99 as HD 188753 and several others, also have three suns in their solar system. In both systems so far one planet has been found in each. These planets might literally get three sunrises and sunsets day.
Compared to our solar system all of this sounds strange but having two suns is fairly common. What aren鈥檛 common are systems like Nu Scorpii and AR Cassiopeiae. Both of these have 7 stars and are the only septenary star system we've found to date.
A sun will go through several different cycles like red giant, going super nova, white dwarf, neutron star and my favourite鈥檚 pulsar and black holes. When one of these stars in either Nu Scorpii or AR Cassiopeiae change into a different stage of its cycle, it will be astonishing to see the effects on the other stars.
Source
https://www.nasa.gov/feature/goddard/2016/newly-discovered-planet-has-3-suns
https://www.nasa.gov/vision/universe/newworlds/threesun-071305a.html
https://web.archive.org/web/20170905183433/http://www.ctio.noao.edu/~atokovin/stars/index.php?cat=HD&number=145501
