The Alien Homeworld

Kinkajou:. Do you think that Zodiac may communicate something to us about the origins of EBEs?
Erasmus: . Perhaps. Of particular interest to me is the sign of Sagittarius. This sign shows half man half beast and suggests that an archer may point the way. Could this be a clue as to the origin of the archangels? Its origin may well date back to an era that leaves us such a clue.

However in Sumerian times, the sign of Sagittarius was all man:
PA.BIL (Archer) --- Defender --- Sagittarius

The sign of Capricorn was a monster:
SUHUR.MASH --- Goat-Fish --- Capricorn

The sign of Virgo seemed to relate to human traits: parenting:
AB.SIN - Her father was Sin --- Virgo

So if there is some wisdom hidden in these names it will take a lot more hard thinking to see through it all.

Kinkajou:. What information have you come across that may relate to the home world of the dominant alien species visiting earth? I would guess these to be the masters of the Greys – let’s call them the Dominants.

Erasmus: . Well, if I had to have a guess as to the home world of all of the Dominants: (using information from the book of Enoch, and other chinks of information we have gleaned over the years), it is a double star system and contains a planet with four moons around the major habitable planet. It would perhaps be in the direction of the constellation of Sagittarius (half man half beast). The home planet is likely to lie somewhere between 40 to 100 light years distant- (using the inferred logistic of travel time as the explanation for the 500-year intervention gaps).

There are a number of associated assumptions here. We assume that the aliens’ spaceships travel something like 0.1c to 0.2 c. We assume that God and the Angels of our biblical history came from this world (the world of the Dominants) or a world in proximity to it. We assume that there is an alien species involved of unknown nature, whom I have called “the Dominants”. I think that the alien species involved is not “the Greys”. But it does appear that the Greys are subservient to this other alien species.

Whether the Greys are a human derivative remains to be seen. That is do “the Greys” actually have human DNA which has been modified to remove the reproductive organs and to limit reproduction?

At this point in time, many of these conclusions are just guesses, although they are best guesses based on what we know today and what we have seen throughout history. They could be completely wrong guesses, but from what I have seen and read from many original books of historic information or from recent reports about alien activities/contacts on earth – it is a guess I would make.

Kinkajou:. Current era alien contacts suggest the system of Zeta Reticuli as the alien home world.

Erasmus: . So, let’s look at this contender for being the home world of the Greys and perhaps of God and the Angels.
The two stars, Zeta 1 Reticuli and Zeta 2 Reticuli are located just over 39 light-years from Earth and are separated from each other by a distance of at least 3,750 Astronomical Units (AU), (where 1 AU is the average distance between Earth and the Sun.)

The stars orbit a common centre of gravity over a period that is likely more than 170,000 Earth years, and are thought to be between 1.5 and 3 billion years old. The stars have a similar structure to our own sun (being yellow main sequence stars) – in effect making them solar analogs.

Zeta 1 Reticuli is a main sequence star of class G3, has a mass equal to about 96% that of the Sun, and a radius about 92% of the Sun.

Zeta 2 is main sequence yellow dwarf star of class G2, has about 99% the mass and 99% the radius of the Sun.
On 20 September 1996, astronomers discovered a planet orbiting star of the Zeta 2 Reticuli.

Kinkajou:. The importance of Zeta 2 Reticuli relates to a map reported by an abductee – Betty Hill. The aliens who abducted Betty Hill claimed that Zeta 2 Reticuli was their home world.

Betty Hill map of Zeta 2 Reticuli

There is another well-known abductee called Bob Lazar. He reported to have worked at Area 51 in Nevada (USA) and to have been involved in reverse engineering alien spacecraft that had been acquired by the US government.

He reports seeing some briefing papers while working in Area 51 that describe the aliens’ home system – Zeta 2 Reticuli, specifically the 4th planet in that solar system. The planet which human astronomers have discovered is a large planet approximately one quarter the mass of Jupiter and is in an orbit around Zeta 2 Reticuli with an orbital period of approximately 18.9 days. For comparison the planet Mercury in our solar system orbits that sun every 88 days.

Zeta 1 Reticuli has no known extrasolar planets. In 2002, ζ1 (Zeta 1 Reticuli ) was examined at an infrared wavelength of 25 μm, but no indication of an excess of infrared radiation was found.

Goo: . From Wikepedia:
In 2007, the Spitzer Space Telescope was used to find an apparent infrared excess at a wavelength of 70 μm around ζ2. This radiation was attributed to emission by a debris disk with a mean temperature of 150 K (−123 °C), theorized to be orbiting the host star at a distance of 4.3 AU.
In 2010, the Herschel Space Observatory, determined the infrared excess as coming from a two-lobed structure that looked like a debris disk seen edge-on. This debris disk interpreted as an analogy to the Kuiper belt with a semi-major axis of 100 AU and a temperature of 30–40 K.

Observations with ALMA from October and November 2017 revealed that the structure observed by Herschel shows no common proper motion with Zeta Reticuli, showing that the alleged debris disk is not real, but rather a case of background confusion.

Erasmus: . It would be hard to imagine a planet closer to its Sun than this. (Zeta 2 Reticuli 1). So, if we follow something called Bode’s law (a law which states each planet is about twice the distance from the sun as its inner neighbour), Zeta 2 Reticulum 2 should be found at approximately 0.28 AU, Zeta 2 Reticuli 3 should be found at approximately 0.56 AU and Zeta 2 Reticulum 4 should be found at 1.12 AU. (This lies between the earth’s position of 1.0 AU and Mars’ position of 1.52 AU – effectively within the “life zone” of a G class star equivalent to our sun).

Star Name: Zeta 2 Reticuli
Distance (Parsecs): 11 pc
Visual Magnitude: 5.24
Mass: Jupiter mass: (J) 0.27(J)

Semi-Major Axis     (AU): 0.14 AU
Period years (y) days (d) : 18.9 d


Kepler's 3rd Law

Kepler’s 3rd law relates the planet’s period or year to its Semi-Major Axis of its orbit.  Mathematically this is expressed as P2 = a3/Mstar.  “P” is the Period measured in earth years, “a” is the Semi-Major Axis measured in Astronomical units (AU), and “Mstar” is the mass of the star measured in Solar Mass units.  Using both of these we can find out the length of the year on each hypothetical planet in the Zeta 2 Reticuli System, INCLUDING Zeta 2 Reticulum 4, Bob Lazar’s purported home of the Greys.

Some Definitions:
Astronomical Unit (AU) = 92.9 million miles = the distance between the Earth and Sun.

The “Semi-Major Axis” is the measurement of the planets orbit, an ellipse, in relation to its star in Astronomical Units.  The Earth’s Semi-Major axis is 1.00 AU.  The “Semi-Major Axis” of a perfectly circular orbit would be the radius of that orbit.

The “Period” is the amount of time it takes to complete one orbit.  A planet’s period is its year.  The Earth’s Period is 365.25 days.
Erasmus: . . Now using Law and Kepler’s 3rd Law:
Planets of the Zeta 2 Reticuli System

So, a Zeta 2 Reticulum 4 year is equal to roughly 1.16 earth years or approximately 422 days. 

Zeta 2 Reticulum 4 is in roughly the same position in Zeta 2 Reticuli’s “life-zone” as the Earth is in the Sun’s “life-zone.” 

Zeta 2 Reticuli is a G1V spectral class star, the Sun is a G2V.  They are both “G” class main sequence stars, the difference between the “2” and the “1” indicates that Zeta 2 Reticuli is a little hotter than the Sun.  The higher the middle number, the lower the temperature.  The “V” means they are both main sequence (middle age) stars but given Zeta 2 Reticuli’s higher temperature, and lower metallicity, it is probably older than the Sun by a couple billion years. 

So basically, the Sun is a little cooler and younger than Zeta 2 Reticuli.

For comparison here is a breakdown of the inner planets of our own solar system.

Dr Axxxx: .  So, the conclusion is that if we were to know the length of the year on Zeta 2 Reticulum 4, this knowledge would provide some validity to the testimony of Bob Lazar. We would expect the answer to be somewhere in the neighbourhood of 410 to 434 earth days.

Erasmus: . The following table shows a sample of Solar Analogs, (not meeting the stricter Solar Twin criteria), within 50 light years and in order of rising distance. The “Solar Analog” category describes suns that are similar to our own sun. “Solar Type” Stars are broadly similar to our own sun.

Solar Analogs:

Kinkajou:. It amazes me just how MANY stars akin to our own sun lie within a relatively close distance to us. Lots!

Using maths, if all stars are within 4 light years of each other (radius 4 ly), then within 50 light years radius there would be (50/4)cubed = 1861 star systems. The galaxy itself is infinitely bigger.

Goo: . Tell us about the “solar types” of the suns above within 50 light years of earth.

Erasmus: . These stars are broadly similar to the Sun.  They are Main Sequence stars with a B-V colour between 0.48 and 0.80, the Sun having a B-V colour of 0.65.  Alternatively, a definition based on spectral type can be used, such as F8V through K2V, which would correspond to B-V colour of 0.50 to 1.00.  This definition fits approximately 10% of stars, so a list of Solar-Type stars similar to our sun using just this criterion would be quite extensive.

Solar-Type stars show highly correlated behaviour between their rotation rates and their chromospheric activity (e.g., Calcium H & K line emission) and coronal activity (e.g., X-ray emission).  As Solar-Type stars spin-down during their Main Sequence lifetimes due to magnetic braking, these correlations allow rough ages to be derived. 

Goo: . Is there a classification for suns that are exceptionally like our sun.
Erasmus: . Yes. They call them Solar Twins.

These stars are even more similar to our Sun, having the following qualities:
* Temperature within 50°K Solar (roughly 5,720°K to 5,830°K)
* Metallicity of 89% – 112% (+ 0.05 Index) Solar, meaning the star’s proto-planetary disk would have had almost exactly the same amount of dust for planetary formation
* No stellar companion, because the Sun itself is solitary
* An age within 1 billion years Solar (roughly 3.5 to 5.6 billion Years)

The following are the known stars that come closest to satisfying the criteria for a Solar Twin.

18 Scorpii is a solitary star located at a distance of some 46.1 light-years (14.13 parsecs) from the Sun at the northern edge of the Scorpius constellation. It has an apparent visual magnitude of 5.5, which is bright enough to be seen with the naked eye outside of urban areas. This "solar twin," a faint star in the constellation Scorpio, mirrors the sun's physical properties in every measurable respect, according to a report at a meeting of the American Astronomical Society. 

Another “solar twin” star is located roughly 184 light-years away, called HD 186302, also is an exceptional match for our sun.
Recent research suggests that most, if not all, stars are born with a binary twin. Our Sun is a solitary star which makes it to some extent unusual. But there's evidence to suggest that it did have a binary twin, once upon a time.

Some other stars are sometimes mentioned as promising Solar Twin candidates, particularly: 
Beta Canum Venaticorum : a  G-type main-sequence star in the northern constellation of Canes Venatici with an apparent visual magnitude of 4.25 and the second-brightest star in the constellation. We calculate this star is 27.6 light-years (8.5 parsecs) distant from the Sun.

37 Geminorum has an apparent visual magnitude of 5.74 and is just bright enough to be visible to the naked eye on a dark night. It is calculated to be 57 light years from the Sun. As of 2012, no extrasolar planets or debris disks have yet been discovered around it. The centre of the star's habitable zone lies at a distance of 1.32 AU.

16 Cygni B  is part of a triple star system approximately 69 light-years away from Earth in the constellation of Cygnus This system consists of two Sun-like yellow dwarf stars, 16 Cygni A and 16 Cygni B, together with a red dwarf, 16 Cygni C. In 1996 an extrasolar planet was discovered in an eccentric orbit around 16 Cygni B with a mass of with a mass at least 1.68 times that of Jupiter . At the time, it had the highest orbital eccentricity of any known planet.  It is very old for a Solar Twin (at least 7 to 8 billion Years Old.

However, all three have temperatures and/or luminosities that are too high for true Solar Twins. 

Furthermore, Beta Canum Venaticorum and 37 Geminorum have too low metallicities for Solar Twins. 

Stellar Neighbourhood

Erasmus: . . Let’s also consider suns by Potential Habitability

Another way of defining a solar twin is as a “habstar” – a star with qualities believed to be particularly hospitable to an Earth-like planet.  Qualities considered include variability, mass, age, metallicity, and close companions.
* At least 3 billion years old
* On the Main Sequence
* Non-Variable
* Capable of harbouring terrestrial planets
* Support a dynamically stable habitable zone

The requirement that the star remain on the Main Sequence for at least 3 billion years and sets an upper limit of approximately 1.5 Solar Masses corresponding to a hottest spectral type of F5V.  Such stars can reach an absolute magnitude of 2.5, or 8.55 times as bright as the Sun, at the end of the Main Sequence.

An important requirement in habitability of stars is “non-variability”. This is defined as a variability of less than 1%, (3% being the practical limit). Variation in irradiance in a star’ habitable zone due to the presence of a companion star with an eccentric orbit is “life” endangering.

Habitability is reduced in multiple star systems (those systems containing 3 or more stars), as gravitational effects between the stars are likely to at least partially destabilise the orbits of the terrestrial planets. Stable orbits in binary systems take one of two forms:  S-Type (satellite or circumstellar) orbits around one of the stars, and P-Type (planetary or circumbinary) orbits around the entire binary pair.  Eccentric Jupiters may also disrupt the orbits of planets in habitable zones.

Metallicity of at least 40% Solar ([Fe/H] = –0.4) is required for the formation of an Earth-like terrestrial planet.  High metallicity strongly correlates to the formation of hot Jupiters, but these are not absolute bars to life, as some gas giants end up orbiting within the habitable zone themselves, and could potentially host Earth-like moons.
One example of such a star is HD 70642.

Kinkajou:. Now back to our theory that the Zodiac may point to the presence of extra-terrestrial civilisations in the Sagittarius constellation. Regrettably the constellations of the Reticulum and Sagittarius are not really that close on the star map.
Goo: . We are just guessing but trying to best guess. And there is no way to check if we are right. You cannot believe much of what the aliens tell abductees and contactees. The Truth is out there, Mulder, but there are lies as well.



Constellation: Reticulum
English name: Reticle
Area (square degrees): 113.936
Quadrant: SQ1
Visible between latitudes: 23°N – 90°S

Constellation:Sagittarius: Archer
Area (square degrees):867.432
Quadrant: SQ4
Visible between latitudes: 55°N – 90°S

Map Night Sky with Reticuli and Sagittarius. The Reticuli constellation is near Orion and the Hydra.(all marked in yellow).

Kinkajou:. So, what else has been said about where our ETs and ETFOs (extra-terrestrial flying objects) come from?

Erasmus: . I think there is definitely an element of the aliens deliberately lying or obfuscating the origins. But some of the problem of understanding their communication is just as likely to be – simple misunderstanding.

If you’re talking to an alien, and he tells you that he had just come from Venus, this may mean that his last port of call was the planet Venus, not that he/she originated from Venus. This issue has appeared in some of the communications with contactees.

Goo: . So, we cannot categorically say that the aliens are liars. Based on my experiences. The best lies are a mixture of truth and lies, where it can be difficult to differentiate where truth ends and lies begin.

Kinkajou:. Indeed.
Moving on. One contactee – Betty Hill – was shown a map which included the home star system of her alien contacts. She reproduced this map for investigators.(on the web page above).At that time, it matched our list of places likely to contain habitable planets. The system was identified as Zeta Reticuli.

Erasmus: . We have talked about this already. It certainly seems possible. The two stars that comprise the Zeta 2 Reticuli system are similar to our sun and are separated from each other by distance of approximately 350 billion miles – about four times the distance of the earth from our own Sun- and require about 10,000 years to orbit their common centre of gravity. The planetary systems likely to sustain life would probably belong to one of the suns only. Planets orbiting around “both” suns would be much more likely to be outside the life zone.

Kinkajou:. There are other alien visitors who claim to have come here (visiting planet Earth) from the Pleiades star cluster.

Erasmus: . This seems very unlikely due to the hot nature of this star cluster. Over 100 hot suns can be found within 0.8 of a light year in parts of this cluster.

An astronomical unit or AU is equivalent to the distance between the Earth and the Sun (approximately 93 million miles).

There are approximately 63,000 AU in a light year. This means that there would be a (solar) sun approximately every 500 astronomical units (AU.). Our closest Star System Alpha Centauri is comparatively 265,000 AU (4.2 ly) away.

This suggests an incredibly hot active and dangerous cluster of suns. Not a place likely to be conducive to the evolution of life – which in my opinion requires stable temperatures, stable environmental conditions, limited radiation and limited danger from into solar debris such as meteorites or asteroids.

The Oort cloud is thought to occupy a vast space from somewhere between 2,000 and 5,000 AU (0.03 and 0.08 ly) to as far as 50,000 AU (0.79 ly) from the Sun. So as a comparison this would mean that the closest solar mass would be far closer to us than the Oort cloud is to our Earth. To be living within the Pleiades cluster would be akin to be surrounded by blazing lights and luminescent gas and dust left over from the formation of the solar bodies.

The Pleiades  also known as The Seven Sisters, Messier 45 and other names by different cultures, is an  open star cluster containing middle-aged, hot B-type stars in the north-west of the constellation Taurus, Although existing at a distance of about 444 light years, it is a very prominent obvious cluster to the naked eye in the night sky. And I would wonder whether the aliens selected this region as their “home” world simply because it is so obvious and familiar to us.
The cluster is dominated by hot blue luminous stars that have formed within the last 100 million years.  Around the brightest stars are dust clouds estimated to be moving at a speed of approximately 18 km/s relative to the stars in the cluster.

Pleiades Star Cluster in Sky

The total mass contained in the cluster is estimated to be about 800 solar masses and is dominated by fainter and redder stars. An estimate of the frequency of binary stars in the Pleiades is about 57%.
The cluster contains many brown dwarfs, which are objects with less than about 8% of the Sun's mass, not heavy enough for nuclear fusion reactions to start in their cores and become proper stars. They may constitute up to 25% of the total population of the cluster, although they contribute less than 2% of the total mass. Gravity affects from errant stellar bodies are likely to destabilise planets – changing their orbits and changing their proximity to the life zone around any individual son.

Kinkajou:. Yes. To me it appears unlikely that EBEs have traveled to Earth from this star cluster. It is a long way away and not very friendly to life or likely stable enough to sustain life. It is more likely that they have simply chosen a widely identifiable astronomical object that people can relate to as a description for people to attach their story too.

Kinkajou:. Other EBEs have said they have traveled here from Orion.
Erasmus: . The Orion Nebula is located around 1,350 light-years away from Earth.
Erasmus: . The Orion nebula is so far away from earth, you would wonder what could possibly justify the risk or expense of traveling all the way to earth. Consider that if you can travel at the speed of light, it takes 1350 years to get here (planet earth). If you can only travel at 1/10 of the speed of light, it would take 13,500 years to get here.

Such distance of travel is only conceivable if the speed of light could be bypassed, for example by traveling through a star gate or a wormhole. But if you can travel that far, that easily, the entire galaxy and perhaps the Universe is your playground. Why bother with insignificant earth.

Goo: . Maybe the food is really good here.

Erasmus: . Perhaps so.

Erasmus: . A claim that aliens have come here from Orion would appear to be false. The immense distances involved limited by the speed of light would suggest travel of thousands of years.
Goo: . And who lives that long? And even if you did live a long time – in the realm of thousands of years, why would you want to spend a significant portion of your life traveling to here, (planet earth).

Map Orion in Night Sky

Kinkajou:. . Other aliens have made the claim of originating from Mars. There are some unusual structures on the planet Mars, most notably in the Cydonia region. It is possible when some of these strange structures on Mars or the moon are looked at in relation to Earth monuments – we may uncover a link to prove alien intervention. We have not explored the solar system yet.

Kinkajou:. How far out is Pluto in AU?
Erasmus: . On average, Pluto is a distance of 39.5 astronomical units, or AU, from the sun. That is almost 40 times farther from the sun than Earth is. Because of its elliptical orbit, Pluto is not the same distance from the sun all the time. Pluto's closest point to the sun is approximately 30 AU.

Again, as a comparison, (between our solar system and the Pleiades cluster) this means that there would be another sun (and even solar system), about 10 times further out than the orbit of Pluto. The sun would still be small but there would be an incredible amount of intersolar matter and energy. There would be an incredible likelihood of collision or interaction between solar sized objects (suns) and any and trapped planetary systems attendant.
Kinkajou:. . A dangerous situation – not likely to give life the billions of years it requires to evolve. Hence the statement that they “come from the Pleiades” is likely an attempt to give an instantly identifiable feature of origin and to create misdirection.
Goo: . In short – a lie.

Kinkajou:. Another contactee reported that the aliens told him that they lived in giant spaceships and had lived in such giant spaceships their entire lives. They were not beholden to planetary masses. (“The spaceships upon which we live and work and learn have been our home for generations. Like all space dwelling races, we are essentially independent of planets”).
Erasmus: . . I suppose living in giant spaceships is possible. The issue with such a living habitat is making up “losses”. How do you replace lost oxygen or loss water? Humanity has not created any habitat systems that are perfectly closed in terms of recycling resources and have no losses.

Every time you need to go outside - for example for maintenance purposes, you run the risk of losing atmosphere- even if you lose 1/1000 of the contents of an airlock. Go outside a thousand times – and you have lost the atmospheric contents of a whole airlock.

Habitats would all require external maintenance and should use multiple airlocks. And there would always be people coming or going between space habitats or on missions of exploration, defence, resource acquisition or just dealing with crises such as meteorite impacts.

Generating gravity would minimise the loss of atmosphere. However, gravity generated from within a spaceship would create a much shallower gravity well than a planet such as our Earth. Gravity around our Earth is essentially stable for hundreds of kilometres up. But gravity generated from within a "machine’s" engine, would exponentially reduce with distance from that engine.

Goo: . In short, the gravity well around a planet is much deeper and hence much less likely to allow the escape of atmospheric gases, than would be the gravity well around a spaceship.
Kinkajou:. But being able to generate gravity as well as locking the doors of your spaceship, would definitely minimise loss of atmospheric gas and water vapour over time. It would at least allow you to reclaim and recycle gases exiting your closed system.

Goo: . In short the claim of living in giant spaceships and being independent of planets is possible. However, it requires a superior level of technology. Recycling technology , Gravity technology and Air-locking technology.

I could however see that some of the aliens/ EBEs could live in giant spaceships in proximity to planetary habitats supplying resources and the suns supplying heat and energy. If the planets in the solar system are hostile or toxic or not located within the life zone of the sun, they can still be exploited to provide resources to support the ongoing existence and operation of giant spaceships.

Kinkajou:. So, summarising again – what is your best guess about where they come from and anything else about them?
Erasmus: . I would guess a double star system, 50 light years away in the constellation of Sagittarius: ½ man ½ beast.
Zeta Reticuli is the second-best guess. It appears to be a double star system, but it is a long way in the sky from the Sagittarius sector of the Milky Way. Many aliens say they come from here but they all tend to lie about “where is home”?

The star (for the Grey’s anyway) is much closer to the red end of the emission range than our sun: hence the big eyes. Temperature 2500K to 3500K.

It is a planet that travels in the habitable range of the solasphere (equivalent to earth’s position) and has a mass of greater than Mars but slightly smaller than the Earth. I would expect a liquid metal core to the home planet with a good-sized magnetic field. The presence of a magnetic field is essential to limit solar flux and radiation damage to a planet and to limit atmosphere lost to space due to the actions of impacting energetic solar radiation and energetic solar particles.
I think a planet needs to be a certain size to retain a water atmosphere. You would guess this from the atomic weights of the atmospheric molecules : namely
H2O 18,, water
N2 28,, nitrogen
O2 32. oxygen

I would guess there is something special about the number 7.

We have seven days in our week, but why seven? None of the aliens we have seen have seven digits, but the number seven must have some serious significance. The seven-day week is present even in China and of course is well known in the West- but why?

Goo: . Some consideration of the nature of suns is in order next.

Erasmus: . The Hertzsprung - Russell diagram (aka the Main Sequence)

Solar suns can be generally categorised by 2 simple parameters – their mass and their age. Mass is important because in general the more massive the star is, the brighter and hotter it must be. Mass determines the pressure within the depths of the sun, which in turn determines its rate of burning nuclear fuel.

The total energy generated in the core must equal the total energy radiated at the surface. This fact generates yet another constraint on solar structure, because the energy radiation of a sphere suspended in a vacuum obeys a law known as the Stefan-Boltzmann Equation:
L = C . R^2 . T^4

(Total luminosity of a hot sphere)

Here L is the luminosity of the star, C is a constant1, R is the radius of the star in meters, and T is the surface temperature of the star in K°.  Note how swiftly the energy radiated by a star rises with T:  doubling the temperature causes its energy output to increase by 16 times.

A star which meets all these constraints is said to be in hydrostatic equilibrium and will therefore be stable. Essentially when the stars core is compressed, the compression causes nuclear burning to increase, which generates more heat, which increases the pressure and makes the star – taking it back to equilibrium.

Kinkajou:. So, I can imagine that to enable life, a stable environment is essential. If the giant nuclear reactor you are living next to is too erratic, it is more likely to cook you, than sustain you even with small changes in energy output.

Erasmus: . The energy output of our Sun has not fluctuated by more than perhaps 0.1% to 0.2% in human history. But even the small fluctuations in energy output significantly affect our climate and the earth’s temperature.

The tight interrelation of temperature, pressure, mass, and rate of nuclear burning means that a star of a given mass and age can only achieve hydrostatic equilibrium at one set of values.  That is, every star in our galaxy of the same mass and age as the Sun also has the same diameter, temperature, and energy output. 

There is no other way for everything to balance. This generates the Hertzsprung - Russell diagram (H-R diagram for short), the relationship between a star's mass and its other properties becomes clearer.

An H-R diagram takes a set of stars and plots their luminosities (relative to the Sun) versus their surface temperatures.  Note that the temperature scale on the H-R diagram in Figure 1 runs backwards, right to left, and that the luminosity axis is highly compressed.  Luminosity increases as temperature increases.

When done for a large sample of stars, we find that the overwhelming majority of the stars fall along a single, narrow band that runs from the bottom-right to the top-left:  that is, from dim and red to bright and white-hot.  Astronomers call this band the Main Sequence, and hence any star along the band is called a main-sequence star.

The main sequence exists because of the inflexible nature of hydrostatic equilibrium- between heat/ light output (temperature) and size. 

Stellar Aging Cycle

The Sun lies essentially in the middle of the diagram, and thus it is neither extremely dim nor extremely bright as stars go.  It shines with a bright yellowish-white colour.

2 – Astronomers traditionally classify main-sequence stars with letters, like so:
O - 30,000 to 40,000 K°
B - 10,800 to 30,000 K°
A - 7240 to 10,800 K°
F - 6000 to 7240 K°
G - 5150 to 6000 K°
K - 3920 to 5150 K°
M - 2700 to 3920 K°

Within each class, numbers from 0 to 9 provide subclasses, with zero being the highest subclass (highest temperature).  The Sun is classified as a G2 star.

There are small numbers of stars well off the main sequence:  they are concentrated in "islands" at the upper right and lower left.  Since the stars at the upper right are very luminous yet nonetheless have cool, reddish surfaces, astronomers call them red giants.  Similarly, since the stars at the lower left are very dim yet also white-hot, they are called white dwarfs. 

Goo: . Tell us about Red Giants and White Dwarfs

Erasmus: . Red giants and white dwarfs occur because stars, change with age and eventually die.   For a star, the cause of aging is the inevitable energy crisis as it begins to run out of nuclear fuel.

Since its birth 4.5 billion years ago, the Sun's luminosity has very gently increased by about 30%. This is an inevitable evolution which comes about because, as the billions of years roll by, the Sun is burning up the hydrogen in its core.  The helium "ashes" left behind are denser than hydrogen, so the hydrogen/helium mix in the Sun's core is very slowly becoming denser, thus raising the pressure.  This causes the nuclear reactions to run a little hotter.  The Sun brightens.

This brightening process moves along very slowly at first, when there is still ample hydrogen remaining to be burnt at the centre of the star. 

But eventually, the core becomes so severely depleted of fuel that its energy production starts to fall regardless of the increasing density.  When this happens, the density of the core begins to increase even more, because without a heat source to help it resist gravity, the only possible way the core can respond is by contracting until its internal pressure is high enough to hold up the weight of the entire star. 

This emptying of the central fuel tank makes the star brighter, not dimmer, because the intense pressure at the surface of the core causes the hydrogen there to burn even faster.  The star's brightening not only continues, it accelerates.

In short, in the end, the nuclear furnace at the centre of every star begins to overheat.  To put numbers on this, when the Sun was formed 4.5 billion years ago it was about 30% dimmer than at present.  At the end of the next 4.8 billion years, the Sun will be about 67% brighter than it is now.  In the 1.6 billion years following that, the Sun's luminosity will rise to a lethal 2.2* Lo.  (Lo = present Sun.) 

The Earth by then will have been roasted to bare rock, its oceans and all its life boiled away by a looming Sun that will be some 60% larger than at present. The surface temperature on the Earth will be in excess of 600 F°.

Around the year 7.1 billion AD, the Sun will begin evolving so rapidly that it will cease to be a main-sequence star.  Its position on the H-R diagram will begin to shift from where it is now, near the centre, towards the upper right where the red giants live.  This is because the Sun's helium core will eventually reach a critical point where the pressure from normal hot gases cannot hold up the crushing weight being piled on it (not even gases heated to tens of millions of degrees). 

A tiny seed of electron-degenerate matter will begin to grow at the centre of the Sun.  Theoretical calculations indicate that it will begin when the Sun's inert helium core reaches about 13% of a solar mass, or about 140 Jupiters.

At this point in its life, the Sun will become unruly.  The mechanism that has been slowly making it brighter for the past eleven billion years – more core pressure, yielding hotter nuclear burning, yielding more helium to enlarge the core – is now accelerated to disastrous levels by the steadily increasing electron-degeneracy. 

Then 500 million years after it hits the critical point, the Sun's luminosity will balloon to 34 Lo, fiery enough to create glowing lakes of molten Aluminum and molten Copper on the Earth's surface.  In only 45 million years more it will reach 105 Lo, and 40 million years after that it will leap to an incredible 2,300 Lo.
By this time the enormous energy output of the Sun will have caused its outer layers to inflate into a vast but very tenuous atmosphere at least the size of the orbit of Mercury, and possibly as large as the orbit of Venus.

The huge size of the solar atmosphere and the enormous heat output of the Sun mean that:  #1) the Earth will have been burnt down to nothing but a seared iron core by this point, if not vaporized altogether – calculations show that it could go either way – and #2) the solar atmosphere will be relatively cool despite the Sun's tremendous energy output.  Thus, the Sun will be both red in colour and extraordinarily luminous.  It will have joined the red giants. 

The number of stars in the red giant part of the H-R diagram is only a fraction of a per cent of that on the main sequence, because no star can remain a giant for long.  When the Sun reaches its maximum luminosity as a red giant, it will be burning more nuclear fuel every six million years than it did during its entire eleven-billion-year lifetime on the main sequence.  This is not sustainable. 

Red giant stars are never really stable in the same sense as the Sun is now.  They are always growing and burning their fuel ever faster, until something stops them.  There is no long-term equilibrium for a red giant.

Goo: . Hence the main issue here is that to sustain life. a life bearing planet must have an earth like sun. The planet must orbit in the life supporting zone of the sun.
And if we are looking for the home of alien visitors, the distances between suns and the difficulty of travel between solar systems mean that our aliens are likely within 60 light years away and very very unlikely to be more than 100 light years away.

Their sun is like to be a main sequence star and not a red giant.

It is possible of course they may well have evolved on one world and moved to colonise another. Yes a Red Giant is unstable over millions of years. But that may mean you can live there comfortably for millions of years before you need to take action to avoid being cooked by the sun’s expansion and heat output.

Due to the short time frames involved, I would consider that adaptations such as large eyes for red suns are more likely to arise as a result of adaptations created by science, rather than evolution.

But then if you you have the science, this sort of adaptation to enable better infrared vision, is a genetic blind turn. An adaptation like this is useful in only one specific environment. Better to just turn on a light bulb. Even a red giant sun would be expected to be luminant enough to enable vision to average human beings.

Inhabitable Planets