The Sun

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A G-type main-sequence star roughly 4.6 billion years old, currently a little under halfway through its core hydrogen supply. Its central temperature is about 15.7 million K and essentially all of its output comes from the proton-proton chain. It is the only star whose interior can be probed directly: helioseismology reads its internal structure from surface oscillations, and neutrino detectors measure the fusion reactions themselves in real time, including the CNO cycle first detected in solar neutrinos by Borexino in 2020. Its future is a model result rather than an observation. Core hydrogen exhaustion is generally placed around five billion years from now, and the detailed evolutionary calculation of Schroeder and Connon Smith (2008) puts the tip of the red giant branch at 7.59 billion years from now, with the Sun shedding about 0.332 solar masses and the Earth failing to escape engulfment despite the orbital expansion that mass loss produces. Not a place on Earth.