SkyEye

Closest Stars

Determining Stellar Distances

It is very difficult to determine the distances to the stars because they are so very far away. The distance to the closest stars can be measured through their parallax. In this technique, the location of a star is painstakingly measured twice, six months apart. (The Earth is on opposite sides of the Sun at the two measurements, providing a long baseline.) If the star is close enough, it will appear to "wobble" slightly compared to the distant stars (which are taken to be fixed in place). The parallax of a star is this tiny angle between the two measurements.

Stars Within 12 Light Years

A number of the closest stars actually form multiple systems. Each component, usually labelled A, B, C, etc., is listed separately. The values for absolute magnitude and distance depend on the accuracy of the observations of the apparent magnitude and parallax. The Sun, which is the closest star to the Earth, is provided for comparison.

Note that brown dwarf objects are not included in this list.

Name or Designation Spectral Type Magnitude Parallax Distance
Apparent Absolute (mas) (pc) (ly)
Sun G2Ⅴ -26.7 +4.9
Proxima Centauri α Cen C GJ 551 Cen M5.5Ⅴe +11.1 +15.5 768.50 1.30 4.24
Rigil Kentaurus α Cen A Cen G2Ⅴ +0.0 +4.4 754.81 1.32 4.31
α Cen B Cen K1Ⅴ +1.3 +5.7 754.81 1.32 4.31
Barnard's Star GJ 699 Oph M4Ⅴ +9.5 +13.2 547.45 1.83 5.97
CN Leo GJ 406, Wolf 359 Leo M6Ⅴ +13.5 +16.6 419.10 2.39 7.80
GJ 411, Lalande 21185 UMa M2+Ⅴ +7.5 +10.5 392.64 2.55 8.32
Sirius A α CMa A CMa A1Ⅴ -1.5 +1.4 379.21 2.64 8.61
Sirius B α CMa B CMa DA2 +8.4 +11.3 379.21 2.64 8.61
BL Cet GJ 65 A Cet M5.5Ⅴ +12.7 +15.6 372.16 2.69 8.77
UV Cet GJ 65 B Cet M6Ⅴ +13.2 +16.0 369.93 2.70 8.81
V1216 Sgr GJ 729, Ross 154 Sgr M3.5Ⅴe +10.5 +13.1 336.12 2.98 9.72
HH And GJ 905, Ross 248 And M5.0Ⅴ +12.3 +14.8 316.96 3.15 10.27
Ran ε Eri GJ 114 Eri K2Ⅴ +3.7 +6.2 310.94 3.22 10.50
GJ 887, Lacaille 9352 PsA M2Ⅴ +7.3 +9.7 304.22 3.29 10.73
FI Vir GJ 447, Ross 128 Vir M4Ⅴ +11.2 +13.6 296.31 3.37 10.99
EZ Aqr A GJ 866 A Aqr M5Ⅴ +13.0 +15.3 293.60 3.41 11.12
EZ Aqr B GJ 866 B Aqr M? +13.3 +15.6 293.60 3.41 11.12
EZ Aqr C GJ 866 C Aqr M? +15.1 +17.4 293.60 3.41 11.12
61 Cyg B Cyg K7Ⅴ +6.0 +8.3 286.15 3.49 11.38
61 Cyg A Cyg K5Ⅴ +5.2 +7.5 285.95 3.50 11.42
Procyon A α CMi A GJ 280 A CMi F5Ⅳ-Ⅴ +0.3 +2.6 284.56 3.51 11.45
Procyon B α CMi B GJ 280 B CMi DQZ +10.9 +13.2 284.56 3.51 11.45
GJ 725 A, Struve 2398 A Dra M3Ⅴ +8.9 +11.2 283.95 3.52 11.48
GJ 725 B, Struve 2398 B Dra M3.5Ⅴ +9.7 +12.0 283.86 3.52 11.48
GQ And GJ 15 B, Groombridge 34 B And M3.5Ⅴ +11.0 +13.2 280.79 3.56 11.61
GX And GJ 15 A, Groombridge 34 A And M2Ⅴ +8.1 +10.3 280.69 3.56 11.61
DX Cnc GJ 1111 Cnc M6.5Ⅴ +14.8 +17.0 279.79 3.57 11.64
τ Cet GJ 71 Cet G8Ⅴ +3.5 +5.7 277.52 3.60 11.74
ε Ind GJ 845 Ind K5Ⅴ +4.7 +6.9 274.80 3.64 11.87
GJ 1061 Hor M5.5Ⅴ +13.1 +15.3 272.24 3.67 11.97

Notes

Proxima Centauri and the two other components of α Centauri form a triple system. Currently, Proxima Centauri is the closest member of this system to the Sun and has one Earth-sized planet orbiting within the habitable zone of the star.

Barnard's Star has the greatest proper motion (apparent angular motion across the sky) of any known star.

Fans of the television series Star Trek will recognize Wolf 359 as the site of the epic battle between Starfleet and the Borg. It is one of the faintest and lowest mass stars yet found.

There have been claims dating back to 1951 of planets orbiting GJ 411 but these have never been confirmed.

Sirius B is a white dwarf, a star at the end of its life. An extremely dense object, it is slowly cooling down because it is no longer fusing atoms in its core to produce energy. At the end of its life, the Sun will also become a white dwarf.

UV Ceti is a flare star, undergoing large changes of brightness in very short time frames. Flare stars are sometimes referred to as UV Ceti variables in honour of this remarkable behaviour. Its companion, BL Ceti, is also a flare star but doesn't exhibit such extreme behaviour.

V1216 Sagittarii is a UV Ceti variable star.

The Voyager 2 spacecraft is headed roughly in the direction of HH Andromedae.

In 1998, a dust ring, perhaps similar to the cloud of comets surrounding our own solar system, was discovered around the very young star ε Eridani, now known as Ran. It has one detected planet named Aegir.

Like many red dwarfs, FI Virginis is a flare star.

The closest neighbour of Lacaille 9352 is EZ Aquarii which is actually a triple system of red dwarf stars.

61 Cygni was the first star successfully observed for parallax. Friedrich Wilhelm Bessel (1784-1846) measured the parallax between 1837 and 1840.

Like Sirius B, Procyon B is a white dwarf.

Both elements of Gliese 725 are x-ray sources.

GQ Andromedae and GX Andromedae form a binary system, orbiting each other in a nearly circular orbit. In 2014 a planet was detected in orbit around GX Andromedae.

The brightness of the flare star DX Cancri can vary fivefold.

τ Ceti features in many science fiction novels by virtue of the fact that it is the nearest single (non-multiple) solar-type star to the Sun. In 2012 it was suggested that the star might contain a system of five planets.

In 2003, astronomers announced that ε Indi was accompanied by a brown dwarf. It was later discovered that the brown dwarf was actually a binary system.

GJ 1061 is so small, it is estimated to be close to the lower mass limit for a star.

Parallax Experiment

You can experience parallax for yourself if you have two functioning eyes. Extend an arm out in front of you and give the "thumbs up" sign. Keeping your arm very still, close your left eye and look at your thumb. Note where it appears relative to the background. Now open your left eye, close your right eye, and do the same thing. Don't move your arm or your head! Your thumb should appear to have moved relative to the background. However, what has actually moved is the observer (your eyes). The distance between your two eyes provides the baseline for this experiment and the angle between the two observations is the parallax. The farther away an object is, the larger the baseline needs to be. This is why the diameter of the Earth's orbit around the Sun is used as the baseline for measuring stellar parallaxes. Even so, this method can only be used for the very nearest stars.

Sources

Stellar data are derived from the The One Hundred Nearest Star Systems, SIMBAD Astronomical Database and the Gaia Archive.