Just thirteen light years away, a red dwarf star is speeding away from us, towing along two rocky planets with it. One of these, five times the size of earth and twice as old, lies in the habitable zone. That means conditions seem to be right for liquid water to exist. This is the nearest planet in a habitable zone discovered till now and scientists are excited at the prospects.
The red dwarf star, called Kapteyn after its 19th century Dutch discoverer is a cool, small star—the most common type of star in our galaxy. While our sun is between five and six thousand degrees Kelvin at its surface temperature, Kapteyn’s surface is more like 3500 degrees K. It is about a third the size of our sun. But it is estimated to have been formed right around the time the universe itself was born some 13.8 billion years ago. So it is very ancient.
Kapteyn and other such primordial stars live in a halo just beyond the inner boundary of our galaxy, forced out of wherever they formed by immense galactic forces. Hence Kapteyn is speeding away from Earth at 245 km per second.
Because of their advanced age, their tendency to form rocky planets and the high precision we have achieved in measuring their velocities, red dwarfs like Kapteyn will continue to be objects of interest for planet-hunting astronomers and astrobiologists alike. This is especially true for objects in the galactic halo, which is home to the oldest known star in the Universe: HD 140283, discovered last year and estimated to be 14 billion years old.
At around 13 billion years it makes one wonder as to what kind of life would have evolved over the countless millenia. By contrast Earth is only 4.5 billion years old and is currently home to every form of life known to exist in the universe.
