Geminga

One of the closest and youngest neutron stars to Earth is a brilliant gamma-ray source 800 light-years away in the constellation Gemini. It turns out to be closely tied to the history and present makeup of the galaxy near the solar system and the recent history of life on Earth, and you can read more about it here:
Geminga

Known as Geminga, the star baffled astronomers for two decades until it was found to send out faint pulses of X-rays four times a second with astonishing faithfulness, an unambiguous signature of a pulsar.Until that discovery what was known was that there was a very strong beacon of gamma radiation coming from Gemini that didn't seem to be connected to any physical object. The name its discoverers' chose was a clever double entendre, both a prosaic abbreviation of "Gemini gamma-ray source" and a clever adoption of a Milanese dialect word meaning "It's not there."

Geminga is there, and is close as far as stellar remnants go. It's also young, cosmically speaking. Its main sequence life ended in a spectacular supernova about 300,000 years ago. People more or less as we are now roamed the Earth back then, in Africa, the Middle East, and Europe, and since Gemini is close to the celestial equator people in both hemispheres would've seen an explosion bright enough to cast shadows at night and see in broad daylight. While they gazed at the sky and puzzled at what was going on, the supernova was so powerful it blasted away much of the interstellar medium around the Sun, and to this day the space around us bears the scar from Geminga's final days of stellar life. Meanwhile high-energy cosmic rays rained down upon the Earth, subtly altering the DNA of the Africans and the Neanderthals. As the Local Bubble bears  the mark of Geminga, so do our genomes.

At least, that's how the story was told in my undergrad astronomy class. Apparently the consensus is now that a series of supernovae in the Pleiades is the more likely explanation for the dearth of matter near the Sun. Either way, we know more than we once did, and it's always stirring to know how we're connected to the cosmos around us.