Sirius
| DISTANCE 8.58 light years |
| MASS A : 2.06 B : 1.02 |
| LUMINOSITY A: 24 B: 0.0080 |
| RADIUS A: 1.71 solar radii B: 0.0084 solar radii |
| TEMPERATURE A: 9,940 K B: 25,000 K |
Sirius, also known as Alpha Canis Majoris, is the brightest star in the night sky. This young 300-million-year-old binary system has an orbital period of 50.09 years, with an average distance between the two stars of about 3 billion kilometres, but this varies over time due to their elliptical orbits. Sirius A, a pure white coloured star (spectral type A0 or A1), has a radius of about one million kilometres, and Sirius B is a small white dwarf with a radius close to 5,000 kilometres (spectral type DA2).
This small white companion is an ageing star that has exhausted its main sources of energy and now shines feebly as it loses heat to its outer layers. It is believed among astronomers that the small white dwarf was once the more massive of the two. As for alien life on an unseen planet in this system, it would be very primitive indeed.
Luyten 726-8
| DISTANCE 8.73 light years |
| MASS A : 0.1225 B : 0.1195 |
| LUMINOSITY A: 0.00147 B: 0.00125 |
| RADIUS A: 0.165 B: 0.159 |
| SURFACE TEMPERATURE A: 2,784 K B: 2,728 K |
Luyten 726-8, also known as Gliese 65, is a binary star system in the constellation Cetus. The stars are separated by an average distance of 1.65 billion kilometres (but varies from 2.1 to 8.8 astronomical units) and take approximately 26.5 years to orbit around each other. As for the type of stars we have lurking in this part of the cosmic neighborhood. Luyten 726-8 A or BL Ceti (spectral type M5.5V) is of the 'flare-up' variety. Luyten 726-8 A or UV Ceti (spectral type M6 V) also shows flare activity, and is slightly dimmer. Not an ideal solar system for finding technologically advanced aliens. Perhaps very primitive alien creatures if they can be protected underground or deep beneath an ocean so long as any hidden planet we don't know about is at the right distance to permit water in the liquid state.
Willem Jacob Luyten discovered the system in 1948 while compiling a catalogue of stars with high proper motion. He noted its exceptionally high proper motion of 3.37 arcseconds per year and catalogued it as Luyten 726-8.
Two dark companions, possibly planets, appear to orbit one or both of these stars, although the orbital period for each has not yet been determined as of 2023.
Ross 154
| DISTANCE 9.67 light years |
| MASS 0.17 |
| LUMINOSITY 0.0038 |
| RADIUS 0.24 |
| SURFACE TEMPERATURE 3,293 K |
| AGE 800 million years old |
Ross 154, also known as V1216 Sgr, is a star in the southern constellation of Sagittarius. It is another unassuming member of the red dwarf 'flare-type' star family (spectral type M3.5V), probably younger than our Sun. It emits harmful, sporadic bursts of radiation every two days or so; and its dim red colour may not be of a wavelength suitable for supporting primitive photosynthesizing micro-organisms, assuming that life was indeed trying to emerge on some unseen rocky terrestrial world in this part of the stellar neighbourhood. Just to add to the difficulties for any alien life in this solar system, the star is said to emit more than its fair share of X-rays. Unless the alien life can live in a cave or underground and/or have a thick shell to withstand the extra radiation or love to have its alien ass turn radioactive and emitting its own radiation into space, this is one place where you are unlikely to find any intelligent and technologically advanced civilisation, at least not native to this star system.
American astronomer Frank Elmore Ross catalogued this star in 1925 and gave it the name we see today.