Ross 248
| DISTANCE 10.306 light years |
| MASS 0.136 |
| LUMINOSITY 0.0018 |
| RADIUS 0.16 |
| SURFACE TEMPERATURE 3,142 K |
Ross 248, also known as HH Andromedae or Gliese 905, is a small star located in the northern constellation of Andromeda. With an age of 20 billion years, this red dwarf 'flare-type' star (spectral type M6V) is considered old compared to the average lifespan of a typical main-sequence star. The flare up nature of this star varies its luminosity in a cyclical fashion that occurs every 4.2 years or thereabouts. Again not an ideal location for a native alien lifeform to establish on an unseen rocky planet. But then again, scientists could be surprised at what they may find here.
In fact, a planet of unspecified mass may be orbiting Ross 248, but this has not yet been confirmed as of 2023. So no one knows whether anything alive could be lurking on its surface.
About the only piece of worthy information to note is how Voyager 2 will pass within 1.7 light years of this red dwarf in approximately 40,000 years. Not the sort of event you want to mark your calendar right now for, but just some information you always wanted to know. And, in terms of its distance to our Sun, this red dwarf will be closer to us than Alpha Centauri within the next 80,000 years. Of course, by then we will have electromagnetic vehicles flying everywhere, some of which will venture out to this star. And while we are thinking about cleaning up our backyard of exceesive numbers of artificial satellites circling planet Earth, hopefully we will be good cosmic environmentalists by deciding to pick up Voyager 2 and bring it back to Earth just to reduce the clutter in space with yet more of our space junk (and so avoid yet another potential collision for those star-faring pilots and passengers from Earth who want to visit this solar system).
Epsilon Eridani
| DISTANCE 10.502 light years |
| MASS 0.82 |
| LUMINOSITY 0.30 |
| RADIUS 0.74 |
| SURFACE TEMPERATURE 5,183 K |
| AGE 950 million years |
Epsilon Eridani is a star in the southern constellation of Eridanus visible to the naked eye in the Earth's night sky. This main sequence star has an orange surface (spectral type K2), which means it is slightly cooler than our Sun. It has three quarters of the Sun's mass and emits a third of its light. However, the age of this star appears to be quite young, at just under a billion years. This also means that the star has a higher level of magnetic activity than our Sun and as a result it is whipping out a particularly strong stellar wind of about 30 times higher than the stellar wind generated by our Sun.
In the 1980s, satellites equipped with infrared detectors found dust around Epsilon Eridani, supporting a planetary system seven times the distance of our Earth from the Sun. More recently, more powerful infrared satellites have detected dust much further out and potentially up to 100 astronomical units. And where there is a dust, there are likely to be planets. In fact, the indirect method of detecting planets through 'wobbles' in a star's motion has successfully revealed a dark companion. At first it was thought to be a brown dwarf in the 1980s because its size was calculated to be about six and ten times that of Jupiter and orbits the star every 26 years at a distance of about 1,200 million kilometres. Canadian astronomers Bruce Campbell, Gordon Walker and Stephenson Yang from the Mauna Kea Observatory in Hawaii first announced the existence of this dark companion in the 1980s after 6 years of careful observation of the star. As of 2000, NASA scientists have been able to confirm that this dark companion is a large gaseous planet (named Epsilon Eridani b) with a mass of 0.66 that of Jupiter, and its correct orbital period is 7.3 years at a distance of about 3.53 astronomical units from the parent star. If these figures are correct, then it would suggest that this planet is much closer to the star than our own Jupiter, which is about 5.2 astronomical units from the Sun. However, there appears to be many more gaseous planets orbiting Epsilon Eridani than our own, lying invisibly in the gap between 20 and 70 astronomical units in the debris disk. Scientists are currently unable to detect all the gaseous planets (let alone the smaller rocky ones lying in the inner orbits that are expected to be part of this large solar system), probably because their number and distribution throughout the solar system makes it difficult to detect each one using the 'wobble' technique.
Is there an inner rocky planet capable of supporting native alien life? Perhaps. However, the youthful age of this star suggests that any life on a rocky planet in the right habitable zone might only be starting out as tiny microbes at this stage, or perhaps the chemistry on an unseen Earth-like planet hasn't quite kicked in at the right moment for life to emerge at the present time. The primitive nature of any alien life in this star system would seem vindicated by the fact that in 1995 a microwave survey of the sky, called Project Phoenix, had searched for signals from extraterrestrials of selected star systems, of which Epsilon Eridani was one, but found no signals. Perhaps we will have to wait another 3.5 billion years before we can get a reply from the aliens if they emerge in this part of the cosmic neighborhood.
Lacaille 9352
| DISTANCE 10.724 light years |
| MASS 0.486 |
| LUMINOSITY 0.0367 |
| RADIUS 0.46 |
| SURFACE TEMPERATURE 3,727 K |
More red dwarfs than you can poke a stick at, and this one is no exception. A small cool red dwarf of spectral type M0.5V and a type of main sequence star. This one is located in the southern constellation of Piscis Austrinus.
About the only notable feature of this solar system is the existence of two super-Earth planets (discovered in June 2020). There is the potential for a third planet as of 2023 but this has yet to be confirmed. If it is a planet, it is likely to be in the habitable zone, but again its size will determine the likelihood of life developing on its alien surface. Given that the red dwarf is fairly stable and emits constant radiation in the safer frequency range, it would not be too surprising if primitive life forms could emerge on some unseen rocky world.
Ross 128
| DISTANCE 11.07 light years |
| MASS 0.168 |
| LUMINOSITY 0.00362 |
| RADIUS 0.197 |
| SURFACE TEMPERATURE 3,264 K |
| AGE 9.45 billion years |
Ross 128 is a red dwarf star located in the zodiac constellation Virgo. The age of this red dwarf is the same as that of our Sun. But its dim orange-red colour (spectral type M4 V) may not give off enough light for primitive plants to evolve on a hidden planet. About the only good thing it has going for it and for alien life is the stability of its nuclear fusion process and its constant emission of light, mostly in the infrared.
Infrared detectors have found dust around this star. On closer inspection, it appears that this red dwarf may host at least one Earth-sized planet, known as Ross 128b. This one is a little more interesting in that the planet is in the inner habitable zone of the star. Technically-advanced alien life may be slim, but primitive alien life could be abundant in this star system. Again, this depends on whether alien life can adapt to the infrared light of its parent star. Worth exploring once humans get cracking on developing an electromagnetic vehicle to take them to the stars.
Luyten 789-6
| DISTANCE 11.1 light years |
| MASS A: 0.1187 B: 0.1145 C: 0.0930 |
| LUMINOSITY A: 0.0001 B: ? C: 0.0001 |
| RADIUS A: 0.1 B: 0.1 C: 0.1 |
| SURFACE TEMPERATURE A: 2,827 K B: 2,650 K C: ? |
Also known as Gliese 866, EZ Aquarii, and LHS 68, Luyten 789-6 is located in the constellation of Aquarius. This one is a little more interesting in the sense that it is a triple star system, and has an age of 20 billion years making it quite old by red dwarf standards. While its age may be favourable to alien life, their spectral type of M5 V would make it a very poor candidate for finding indigenous life in this star system. In fact, due to the high rotation rate of the main star (Luyten 789-6 A), it sends out flares every now and then. The other two red dwarfs, however, appear more stable. They orbit each other at a distance of 0.8 astronomical units making one complete orbit in 3.8 days, and then revolves around the main red dwarf lasting 823 days to complete one orbit. These two red dwarfs lying so close to each other would allow a planet in the habitable zone to orbit them with great stability, but so far no planet has been detected.
Other than that piece of interesting news, this triple star system will make it closest approach to our Solar System in approximately 32,300 years at a distance of 8.2 light-years from the Sun.