A vast canvas
When we look up into a dark sky, we’re accustomed to seeing the cosmos as an unimaginably faraway thing. Distances don’t really register. The few things we can see move in short intervals — the Sun, Moon, and planets — are exceptions. Everything else may as well be painted onto a vast canvas in the heavens.
But of course, in reality we look out into an incredibly huge, threedimensional space with countless objects at all manner of distances. In this issue, science writer Stephen Ornes introduces us to a special class, the 10 nearest stars. These closest celestial neighbors beyond our own solar system have lots to tell us about stars, about stellar evolution, and about the space around us in the Milky Way Galaxy.
You probably know that the closest star to us is Proxima Centauri, an M (red) dwarf a hair over 4.2 light-years away that orbits its main binary system of Alpha Centauri A and B. Although this triple system is very close on a galactic scale, such distances are vast. The fastest spacecraft we can realistically conceive of would take more than 70,000 years to travel to Proxima Cen.
Many more interesting stars lie in our cosmic neighborhood. Discovered by the great American astronomer Edward E. Barnard, Barnard’s Star is the fastest-moving star in the sky, relative to the background. Another red dwarf, it speeds along at more than 10 arcseconds a year. Star of a Star Trek episode, our neighbor Wolf 359 is yet another red dwarf — you get the picture; they are the most common stars — just 7.9 light-years away. But our neighbors are not all red dwarfs. There is also the brightest star in the sky, mainsequence Sirius, which lies a mere 8.6 light-years away and hides a difficult-to-spot white dwarf companion.
Not only can we read about these close stars in our neighborhood, we can also observe them. The story includes finder charts for those who want to venture out with a telescope and peer closely at some of the closest stars to our Sun.