List of nearest stars and brown dwarfs


Some 52 stellar systems beyond our own, the Solar System, currently lie within of the Sun. These systems contain a total of 63 stars, of which 50 are red dwarfs, by far the most common type of star in the Milky Way. Much more massive stars, such as our own, make up the remaining 13. In addition to these "true" stars, scientists have identified 11 brown dwarfs, and four white dwarfs. Despite the relative proximity of these 78 objects to Earth, only nine are bright enough in visible light to reach or exceed the dimmest brightness to be visible to the naked eye from Earth, 6.5 apparent magnitude. All of these objects are currently moving in the Local Bubble, a region within the Orion–Cygnus Arm of the Milky Way.
Based on results from the Gaia telescope's second data release from April 2018, an estimated 694 stars will possibly approach the Solar System to less than 5 parsecs in the next 15 million years. Of these, 26 have a good probability to come within and another 7 within. This number is likely much higher, due to the sheer number of stars needed to be surveyed; a star approaching the Solar System 10 million years ago, moving at a typical Sun-relative 20–200 kilometers per second, would be 600–6,000 light-years from the Sun at present day, with millions of stars closer to the Sun. The closest encounter to the Sun so far predicted is the low-mass orange dwarf star Gliese 710 / HIP 89825 with roughly 60% the mass of the Sun. It is currently predicted to pass from the Sun in million years from the present, close enough to significantly disturb our Solar System's Oort cloud.
The easiest way to determine stellar distance to the Sun for objects at these distances is parallax, which measures how much stars appear to move against background objects over the course of Earth's orbit around the Sun. As a parsec is defined by the distance of an object that would appear to move exactly one second of arc against background objects, stars less than 5 parsecs away will have measured parallaxes of over 0.2 arcseconds, or 200 milliarcseconds. Determining past and future positions relies on accurate astrometric measurements of their parallax and total proper motions, along with spectroscopically determined radial velocities. Both of these measurements are subject to increasing and significant errors over very long time spans, especially over the several thousand-year time spans it takes for stars to noticeably move relative to each other.

List

Visible to the unaided eye
Brown dwarf or Sub-brown dwarf
White dwarf

The classes of the stars and brown dwarfs are shown in the color of their spectral types. Many brown dwarfs are not listed by visual magnitude but are listed by near-infrared J band apparent magnitude due to how dim they are in visible color bands. Absolute magnitude is a measurement at a 10-parsec distance across imaginary empty space devoid of all its sparse dust and gas. Some of the parallaxes and resultant distances are rough measurements.

Distant future and past encounters

Over long periods of time, the slow independent motion of stars change in both relative position and in their distance from the observer. This can cause other currently distant stars to fall within a stated range, which may be readily calculated and predicted using accurate astrometric measurements of parallax and total proper motions, along with spectroscopically determined radial velocities. Although predictions can be extrapolated back into the past or forward into the future, they are subject to increasing significant cumulative errors over very long periods. Inaccuracies of these measured parameters make determining the true minimum distances of any encountering stars or brown dwarfs fairly difficult.
One of the first stars known to approach the Sun particularly close is Gliese 710. The star, whose mass is roughly half that of the Sun, is currently 62 light-years from the Solar System. It was first noticed in 1999 using data from the Hipparcos satellite, and was estimated to pass less than from the Sun in 1.4 million years. With the release of Gaia's observations of the star, it has since been refined to a much closer, close enough to significantly disturb objects in the Oort cloud, which extends out to from the Sun.
The second-closest object known to approach the Sun was only discovered in 2018 after Gaia second data release, known as 2MASS J0610-4246. Its approach has not been fully described due to it being a distant binary star with a red dwarf, but almost certainly passed less than 1 light-year from the Solar System roughly 1.16 million years ago.