Scarlet Skies

Red dwarfs are the most common form of star in the Milky Way. Lower in mass than our sun, cool and dim, they initially appear poor prospects as abodes of life. However they have been increasingly identified as prime targets for surveys seeking habitable planets - because they are long lived and plentiful. They are also a good place to look because a planet in the habitable zone (if present) may be relatively easy to detect - and as the old saying goes it's best to look for lost keys under a lamp, not because they are more likely to be there, but because there's a chance of finding them if they are. As a result, red dwarfs are experiencing a resurgence in science fiction - but SF has long been aware of the potential of these smouldering stars.

The first red dwarfs to be found, including our closest neighbour Proxima Centauri (discovered 1915) and the nearby Barnard’s Star (discovered 1916), were, understandably, close to the Sun. Given that even the nearest of these objects is too faint to be seen without a telescope, the existence - and sheer number - of such stars came as something of a surprise to astronomical surveyors, and uncovering their properties on galactic scales necessarily awaited the modern era of large telescopes and sensitive detectors. While the term red dwarf can be applied fairly loosely to any stars fainter than the sun, it is generally applied to stars with the Harvard classification M [1]. They have masses from around 0.6 times that of the Sun (Msun) down to the hydrogen-burning limit at around 8% Msun, and surface temperatures in the range 2000-4000K. As a result of this, the majority of the light they emit is at the red end of the optical spectrum or in the thermal infrared. They also tend to be erratically variable - active stars which release giant flares at unpredictable intervals. Despite this they are extremely long lived - with main sequence lifetimes extending to hundreds of billions of years. 

The very different nature of red dwarfs relative to our familiar and nurturing Sun led to an early interest in them by SF writers. Isaac Asimov’s early classic Nightfall (Astounding, Sep 1941) imagined a world with 6 suns in the sky, and a people that never knows darkness - except once every two thousand and forty-nine years. At that interval, a devastating eclipse occurs at a time when the only sun in the sky is Beta, a dim and cold red dwarf. As the eclipse approaches, with Beta at aphelion and the other suns no longer visible, the characters begin to notice how even a handful of hours dependent on the red dwarf affect the habitability of their environment:

“It’s freezing outside. The wind’s enough to hang icicles on your nose. Beta doesn’t seem to give any heat at all, at the distance it is.”

The dim and red-tinged light from this star adds tension to the unfolding catastrophe, even before night falls with dramatic effect.

Another evocative description of a red dwarf system can be found in James Blish’s novella The Sargasso of Lost Cities (1953). In this future of city-turned-spacecraft, most of the world’s urban centres have abandoned Earth and set off into space as ‘okie’ cities, protected by ‘spindizzy’ fields. When a Galactic financial crash eliminates most of the assets of the flying cities, however, a large number of the cities find themselves exiled to a ‘jungle’ or ‘sargasso’ - an accumulation of destitute and hopeless populations. In a system with a close binary of sunlike stars, a red dwarf is a distant companion, four light years distant:

“Around this tiny and virtually heatless fire, more than three hundred Okie cities huddled. On the screen they passed in an endless, boundary-less flood of green specks, like a river of fantastic asteroids, bobbing in space and passing and repassing each other in their orbits around the dwarf star. The concentration was heaviest near the central sun, which was so penurious of its slight radiation that it had been masked almost completely by the Dinwiddie code-lights when Hazleton first spotted the jungle.”

It becomes clear that hierarchy in this jungle strictly determines the allowed orbits, such that only the most powerful cities (in both the figurative and literal sense) can get close to the meagre light and heat source:

“Obviously, three hundred-odd Okie cities could not all huddle close enough to a red dwarf to derive any warmth from it. Somebody had to be on the outside. It was equally obvious, and expectable, that the city with the most power available to it should be one drawn up the most cosily to the dull stellar fire, while those who most needed to conserve every erg shivered in the outer blackness.”

Eventually, and unsurprisingly, the cities rebel against this status quo and manage to break out of the jungle and back towards the light.

Hard science fiction author Hal Clement was also an early visitor to red dwarfs in his short story Trojan Fall (Astounding, June 1944). In this story a criminal attempts to flee from Earth in a private spacecraft, massively underestimating the complexity and difficulties of navigating over astronomical distances. Of the twelve stars in his range, only four are listed as single, and the one he selects as a hiding place proves instead to be a close binary system:

The stars were red dwarfs, small and dense. They would have been seen to be irregular variables if anyone had looked long enough, for their surface temperatures were so low that “cirrus" clouds of solid carbon particles formed and dispersed at random in their atmospheres. The larger sun was perhaps a hundred thousand miles in diameter, the other only slightly smaller. Their centers were roughly half a million miles apart, and the period of revolution about eight hours. In spite of their relatively high density, there were very noticeable tidal bulges on both.

All these facts would have been of absorbing interest to an astronomer seeking data on the internal structure of red dwarf stars; La Roque didn’t know any of them, and at first didn’t give a darn.”

Given that a cool 1000K star of this kind only gives reasonable temperatures within a million miles or so of its surface, the binary nature of this system presents a problem - the habitable zone distance is comparable to the separation of the stars. In such a close orbit, tidal forces are also significant. Eventually trying to hide in the trojan point of the system (the third corner of an equilateral triangle with the two suns), La Roque discovers that he has also underestimated the instability of a three-body system of this kind.

Clement was not the only one to consider red dwarfs in multiple star systems. In Get Out of My Sky (novella, first appearing in Astounding, Jan 1957) James Blish described a pair of twin planets (orbiting their common centre of mass), which are in a trailing co-orbit with a red dwarf, together orbiting a larger, hotter star, all on the edge of an intense stellar cluster. This leads to a fascinating series of shadows and optical effects:

“The red sun looked directly down on the deck from the zenith, coloring everything but each man’s immediate shadow, the one of the three that the ancients had called the Soul. It made it seem as though the cruiser were forging through a fog of blood.

The second shadow, the Mind, stretched out along the deck, very blurred along the edges. It was being cast by the glittering mass of star-fire at the northern horizon—the great cluster of stars of which this whole system was a marginal member. The third shadow, the Breath, was as usual sharper but dimmer than the Mind, for the white sun which cast it, now thirty degrees above the horizon in the west, was less brilliant than the star cluster. Both, like the Soul and everything else, were tinged by the red sun.”

This unsurprisingly focusses the attention of the people of the planet Home on the skies, where the presence of their twin planet Rathe becomes an increasing source of tension.

The developing understanding of red dwarf systems and their properties was certainly known to both science fiction writers and their readers. As early as 1963, Isaac Asimov’s essay Twinkle, Twinkle Little Star appeared in the Magazine of Fantasy and Science Fiction (Oct, 1963) and discussed the 51 stars then known to lie within five parsecs of the Sun, of which 32 were red dwarfs. Asimov pointed out that red dwarf stars may be of interest to astronomers studying the variation in spectral lines caused by the presence of otherwise invisible bodies. Indeed, he noted that several were now known to have super-Jupiter mass companions (now recognised as Brown Dwarfs rather than planets, but described then as black dwarfs or sub-stars) due to the influence of other bodies on their motion.

Moving into the modern era, with the discovery of the first exoplanets (planets outside our solar system), this radial velocity method came into its own; spectrographs became sufficiently sensitive and stable to detect not only the perturbation to a star’s spectra caused by a hidden red dwarf or even fainter brown dwarf, but also by planets. Importantly this perturbation scales sensitively with the distance between the star and the planet, and also with the mass ratio between them. As a result, low mass red dwarfs will show measurable perturbations for planets orbiting in their habitable zones, which, as Clement noted in Trojan Fall, lie very close to the host star. Those habitable zones are not determined by the amount of light in the wavelength range visible to human beings, but rather by the amount of thermal radiation which a planet can intercept, allowing it to reach equilibrium temperatures suitable to support atmospheres and liquid water.

A different perspective on red dwarfs, but one no less informed by astronomical knowledge is provided by Philip Latham in his short story The Red Euphoric Bands (Galaxy, Dec 1967). This is written from the point of view of an astronomer, Finch, who is not a success, although as he tells us

“I’m the discoverer of Finch 17, the nearest star to the Earth. Nobody can take that away from me. Stumbled on it by pure dumb luck. Red dwarf about 2 ly’s away, half the distance of Alpha Centauri. Created a sensation at the time.”

Curiously, Finch discovers that the interstellar comet Ikegawa, which is about to make a very close approach to Earth indeed, has originated from precisely the direction of Finch 17 (within 5 minutes of arc, or a twelfth of a degree). The comet is approaching a world already on the brink of war and looking for an omen. However, despite initial terror and hysteria at its appearance, the gases from the comet’s coma prove to have a euphoric and soothing effect, and the threat of war recedes. Looking back at a decade of astronomical photographic plates of Finch 17, Finch is able to prove that the comet is on an extended elliptical orbit between the two stars and goes public with the idea that:

“I think there is another world where beings exist probably exceeding ourselves in intelligence. In some way— don’t ask me how— they fore-saw years ago that a world war was inevitable. And so, lest they be the only world remaining where intelligent life exists, they sent this cometlike body across space to save us.”

Philip Latham was the pen-name of astronomer Robert S Richardson, and he uses his knowledge to give the story a sense of realism by including orbit diagrams and calculations, as well as an insight into life as a university lecturer. In this regard, it’s interesting to see that at least one astronomer considered a red dwarf (albeit a fictional one) as a hypothetical host for a habitable world.

Poul Anderson’s short story Admiralty (F&SF, Jun 1965, one of the components of his 1965 fix-up novel The Star Fox) is interesting in that it considers the impact of a red dwarf primary on the hypothetical population of its planets. This story is a space opera set in a future of extensive human space trading, and follows the adventures of a privateer, Gunnar Heim, during a conflict against an alien species from the planet Alerion. The Aleriona, described as clawed and tailed, with a fine white fur, wear contact lenses to protect dark-adapted eyes, and maintain a dim red light within their buildings on a human-occupied world. One Alerion lord tells Heim a little more:

“Old is Alerion,” he chanted, “old, old. Long-lived are the red dwarf stars, and late appears life in so feeble a radiance. Once we had come to being, our species, on a planet of seas vanished, rivers shrunk to trickles in desert, a word niggard of air, water, metal, life — uncountable ages lingered we in savagehood. Ah, slow was the machine with coming to us. What you did in centuries, we did in tens upon thousands of years; and when it was done, a million years a-fled, one society alone endured, swallowed every other, and the machine’s might gave it upon us a grip not to be broken. Starward fared the Wanderers, vastminded the Intellects, yet were but ripples over the still deep of a civilization eternity-rooted. Earth lives for goals, Alerion for changelessness.”

Unfortunately, this philosophical and psychological difference lies at the root of the conflict.

Also writing from a Hard SF perspective, Robert L Forward described the planetary system of red dwarf Barnard’s Star in his novel Rocheworld (1990). As I discussed in an earlier blog on peculiar planets, this is in fact a pair of worlds in such a close binary orbit that their surfaces are distorted and their atmospheres overlap. This twin planet itself orbits, along with a larger gas giant, Barnard’s Star. A human exploratory mission discovers that not only is the Rocheworld habitable but it is inhabited by large and intelligent aquatic creatures in the seas of the wetter half of the system. An interesting feature of Rocheworld is the recognition that the planetary orbits around such a small star, and particularly those in the habitable zone, are small, making a survey mission visiting multiple planets feasible.

The idea of double-planets orbiting red dwarf stars (as seen in Rocheworld and Get Out of My Sky, amongst others) also put in an appearance in "Grammar Lesson", part of 3 Vignettes by Larry Niven, which appeared in Cosmos magazine in May 1977. All three vignettes are barroom scenes set in the "Draco Tavern" in a future in which humans have an uneasy relationship with the alien Chirpsithtra. In "Grammar Lesson", a chirpsithtra patron tells the story an encounter with another alien race, the Ilawn. Both species had evolved in red dwarf systems, and colonised thousands of similar systems across the galaxy. However the chirpsithtra evolved on a "one-face world" - i.e. tidally locked, and with a constant wind blowing around the planet to redistribute heat from the primary.

But there are couplet worlds too. Around a red dwarf sun the planetary system tends to cluster close. Often enough, world-sized bodies orbit one another. For tidal reasons they face each other; they do not face the sun. Five percent of habitable worlds are found in couplets.”

“The ilawn came from one of those?”

“You are alert. Yes. Our ilawn prisoners were most uncomfortable until we shut their air conditioning almost off. They wanted darkness to sleep, and the same temperatures all the time. The conclusion was clear. We found that the worlds they had attacked in the earlier stages of the war were couplet worlds.”

This led to a strategy that ultimately ended the conflict, since the chirpsithtra simply evacuated couplet planets - and used them to force the ilawn to the negotiating table.

This story is interesting in that it actually discusses the atmospheric effects that might make a tidally-locked planet habitable, decades before this was studied in any real example, and hypothesised the importance of twin planets in providing a different, but equally valid habitable paradigm.

A trickle of stories set on planets with red dwarf primaries continued through the 1970s, 80s and 90s (although, ironically, not including the BBC television sit-com Red Dwarf, which was just set on an asteroid mining ship of that name). In 1990, the red dwarf Wolf 359 (the fourth nearest star system to Sol, at just eight light years) was the site of a final last-ditch battle to defend Earth from the advancing Borg in Star Trek: The Next Generation (episodes “The Best of Both Worlds” part I and II, 1990). Otherwise, the dimly-lit planets of red dwarfs are largely absent from television and film science fiction, with appearances limited to brief mentions.

An interesting idea, which crept into science fiction from astronomical research during the 1980s, was that the sun might itself have a faint red dwarf companion [2]. This idea has existed for well over a century but was raised in 1977 by E R Harrison in an article in Nature and provoked significant discussion in the years thereafter. The name Nemesis was coined after it was suggested that such a companion could be responsible for periodic mass extinctions. Given that these stars emit the majority of their light in the infrared, and that a companion might be expected to be in the ecliptic plane of the Solar System (and thus hidden behind the zodiacal dust, asteroid belt and Oort cloud), infrared surveys at the time were insufficient to rule out the possibility. What’s more, at least 20% of sun-like stars are known to have companions. While this has now been ruled out to a high degree of confidence by modern infrared surveys, it has left a legacy in SF.

Isaac Asimov explored this idea in his 1989 novel Nemesis. In a future a couple of centuries hence the Solar System has been efficiently populated by self-contained Settlements - O’Neill type rotating habitats. One of these makes a breakthrough in near-light-speed travel. This settlement, Rotor, launches a probe and discovers a red dwarf star just two light years from our Sun, but dimmed by a dust cloud lying between us. Rotor opts to leave the Solar System and travel to this star without revealing its existence to others, in the hope of establishing an independent civilisation [3]. However the red dwarf, dubbed Nemesis, proves not to be a distant companion, but rather to be an independent star which happens to be on a direct line of travel towards the Solar System and will pass close enough to disrupt Earth’s habitability within five millennia. As a result, while Rotor is getting to grips with its new environment, Earth finds it imperative to discover not just near-light but superluminal travel.

Throughout the book, characters spend a lot of time telling one another how unlikely it is that a red dwarf can host a habitable planet, invoking the likelihood of tidal locking as an argument. Asimov gets around this by giving Nemesis a super-Jovian companion (either a very large gas giant or a small brown dwarf) called Megas, which is tidally locked to Nemesis. Megas in turn has an Earth-sized satellite, Erythro, which is tidally locked to it, but which has an orbit which is highly tilted with respect to the orbit of Megas and Nemesis. This somewhat contrived arrangement means that Nemesis moves through Erythro’s skies on a daily cycle. Together with an atmosphere and ocean to recirculate heat, this is enough to keep the entire planet at a habitable temperature. It even has a breathable atmosphere...

“Breathable, but not really comfortable. The light level is wrong. When you get outside the Dome, you’re bathed in a pinkish light, tending to orange when Nemesis is high in the sky. It’s bright enough. You can read. Still, it doesn’t seem natural. Then, too, Nemesis itself doesn’t look natural. It looks too large, and most people think it looks threatening and that its reddish light makes it seem angry - and they get depressed. Nemesis is dangerous in actual fact, too, at least in a way. Because it isn’t blindingly bright, there is a tendency to gaze at it and watch for sunspots. The infrared can harm the retina. People who must go out in the open wear a special helmet for that reason - among other things.”

Such an impact on human psychology, particularly for early settlers, is a commonly-discussed issue where human habitability of red-dwarf planets is imagined. The impact of sunlight (or lack thereof) on human health (physically through production of vitamins and in terms of mental health) is well established and would have to be replaced on a red dwarf planet through artificial lighting.

The idea of a red dwarf companion to Sol - together with an explanation for its absence - also appeared in the Gregory Benford and Larry Niven collaboration The Bowl of Heaven (novel, 2012) and its sequel Shipstar novel, (2014).

Here a human exploration ship en route elsewhere stumbles across a partial Dyson sphere (a megastructure designed to enclose and capture the energy from a star), which uses its central star’s focussed light as a motive power source. This central star proves to be the original binary partner of our Sun, repurposed by an ancient civilisation and so lost to our skies before humanity evolved. A red dwarf is actually a good choice for such a purpose. Rather than the Dyson sphere needing to have a radius comparable to 1au (the distance from the Earth to the Sun) to make it habitable, it can be much smaller. However Benford and Niven didn’t really discuss the impact of the redder light on the environment.

With the discovery of the first exoplanets in the late 1990s, interest in habitable planets resurged. The subsequent deliberate targeting of red dwarf stars by exoplanet surveys led to the discovery of at least two high profile red dwarf planetary systems with potentially habitable exoplanets. Our nearest red dwarf, Proxima Centauri, is now confirmed to host at least 1 and maybe 3 or more planets, with Proxima b (announced 2016) in the habitable zone.

The less well known but more impressive Trappist-1 system was revealed in 2016-17 to contain no fewer than 7 planets, at least 4 of which lie in its habitable zone. To give a sense of the small scales here, the entire Trappist-1 system, from star to outermost known planets, would fit well inside the orbit of Mercury if overlaid on our Solar System, with the longest planetary period being just 19 days. The science journal Nature actually opted to commission a science fiction short story directly inspired by the research paper, which appeared in the same issue together with a blog entry describing its creation. The Terminator, by Laurence Suhner appeared in February 2017, in the one page “Futures” feature that is located in the back of every Nature issue. It imagined a future in which a human colony ship reached the TRAPPIST-1 system, finding and settling two of its tidally-locked but habitable worlds. However another of the worlds proves to be inhabited by an ancient civilization that warn them off, refuse contact and remain a mystery. 

The discoveries of planets in red dwarf habitable zones have helped to inspire a new generation of stories involving red dwarf planets. Proxima (novel, 2013 Stephen Baxter), for example, describes the eponymous system, and is just one of many science fictions set in the Alpha/Beta/Proxima Centauri system (which I’ll come back to another time). Baxter also imagined survivors of a disaster on Earth attempting to settle Earth III, a tidally-locked planet with a red dwarf primary, in Ark (novel, 2016).

Red dwarf planets are indeed likely to be tidally-locked, that is only ever turning one face to their sun. Tidal forces scale more strongly with distance than the more familiar force of gravity, and so are far more likely to have brought rotation to a relative standstill in systems with spatial scales as small as those in red dwarf habitable zones. This is certainly believed to be true in many of the known red dwarf planetary systems - although in some cases planet-planet interactions may prevent full synchronisation (as is also the case, for example in Forward’s Rocheworld). For a Dyson sphere, as in The Bowl of Heaven, tidal locking is unlikely to be a problem, and is even an advantage. For a world with a relatively dense atmosphere or oceans, the differential heating will drive circulation, with strong winds or currents carrying heat from the irradiated side to the dark side and evening out their temperatures, while planets where atmosphere is sparse may only be inhabitable as twilight worlds - in a narrow strip around the terminator between night and day. Isaac Asimov deliberately avoided this problem by setting his Nemesis on an Earth-sized exomoon orbiting a giant planet, which itself was in orbit of the red dwarf, and is sufficient to stop the exomoon tidally locking to the primary. Suhner, in The Terminator, instead imagined an extensive ocean, circulating through both hemispheres and providing thermal mixing.

Moving further into the era of post-exoplanet discovery, Allen M Steele made use of a red dwarf planet for his Arkwright series. In A Long Wait (Asimov’s, Jan 2015), we learn of humanity’s first starship, the Galactique, en route to the (genuinely exoplanet-hosting) red dwarf Gliese 667 [4]. The narrator character is a child born to and raised by family at the Juniper Ridge observatory, and a precocious early learner:

“I also knew something most kids didn’t know: the details of humankind’s first starship, now bound for Eos — or, if you want to get technical, Gliese 667C-e, a terrestrial planet in close orbit around an M-class red dwarf twenty-two light-years from Earth. Every day, my family and the Crosbys took turns standing watch in the observatory.”

Rather than colonists, Galactique carries embryos to be raised on the distant world after many decades travel. Unfortunately, she takes damage during a flyby of another red dwarf Gliese 832, midway to Eos, and Earth faces a threat from a potential killer asteroid, so it’s not until the end of the story that we learn that the vessel did reach Gliese 667 after all.

The follow-up story, The Children of Gal (Asimov’s, April/May 2015) is set on the new super-Earth world, Eos, in orbit of its red sun, Calliope. Galactique, and particularly its semi-sentient AI, have become worshipped as the deity Gal by a people for whom Earth is just a legend. Eos itself has been terraformed and seeded with genetically-engineered Earth life, including humans. This descent into oral history and myth must be explained by the first follow-up mission from Earth to the new colony:

“Calliope is what’s known as a red dwarf” As Russell spoke, he turned to walk backward on his curiously shaped hinds. Sanjay was amazed by the improbable and yet so casual movement, but Russell didn’t seem to notice the way Sanjay stared at him. “They’re generally smaller and cooler than Earth’s sun, but every now and then. . . every few thousand years or so . . . they tend to spontaneously enter phases in which they grow hotter and brighter due to solar prominences. . .”

With Calliope entering an unexpected variable phase not long after settlement began and a giant storm imminent, the nascent colony was divided:

“I know you’re not going to understand this, so I’ll try to make it simple . . . stars like Calliope emit more than just heat and light. They also cast other forms of radiation that you can’t hear, see, or feel, but which are present anyway. The radiation became so intense that it not only destroyed Galactique’s ability to . . . um, talk to the teachers and the transformers, but also even the islanders’ ability to communicate with those who stayed on the mainland.”

As a result, while the children of one settlement retained some part of their history, the other did not. We see relatively little of the conditions of the planet itself, although the necessity of genetic engineering of both terrestrial humans and animals, and the need of regular-human visitors for exoskeleton support frames, suggest they are quite different to those of Earth.

Also published since the modern discovery of red dwarf planets, To Be Taught If Fortunate (novella, Becky Chambers, 2019) considers the nature of life on a red dwarf planet in more detail. It describes a crowd-funded effort to explore the four planets in the habitable zone of a fictional red dwarf system about 14 light years from Earth. Again this is made plausible by the proximity of each planet to the others, although even so the astronauts spend years of travel time between planets in a form of suspended animation.

In the story, Aecor (technically an icy exomoon of a gas giant), Mirabilis (a temperate super-Earth with black-leaved vegetation optimised for absorbing infrared), Opera (an ocean world) and Votum (a barren, tidally-locked planet) are each is found to contain a distinct and fascinating biosphere, which must be protected from the humans by strict biosafety protocols. These worlds host organisms in which the chirality of amino acids (a fundamental property of life) proves that it must come from a completely different and distinct origin from the life elsewhere, finally ruling out the possibility of a single-origin panspermia giving rise to all life across the galaxy, and also suggesting life may adapt to more environments than previously thought.

The habitability of red dwarf planets remains a subject of active debate today. The erratic variability of red dwarfs, their flaring and the tidal locking that results from the small size scales of their habitable zones may all mitigate against the long term survival of life. However they do not preclude it, and the discovery of a new category of planet, the superEarths, has improved the chances of even tidally locked planets retaining an atmosphere which might protect them from both flaring and extreme temperature differences between hemispheres. The long lives of red dwarfs might make them a safer bet for ancient civilisations than relatively short-lived stars like the Sun. And while their red spectra might favour life with infrared vision, and dark red or even black vegetation, they can certainly power habitable zones in which humans (provided with an appropriate atmosphere) could potentially exist. 

It’s interesting to see how the authors of science fiction, both before and after the discovery of red dwarf exoplanets, have adapted to our increasing knowledge of the prevalence of red dwarfs, how they have communicated shifts in that knowledge to a much broader community. It’s also interesting to see red dwarfs reappearing in contemporary science fiction, now reflecting the most recent exoplanet discoveries, and again circulating these to an interested and engaged readership. While the reverse - the impact of science fiction on the science - is perhaps a little direct, it’s now well established that many of the astronomers working in the exoplanet area were inspired by the field - including the exoplaneteers studying red dwarf systems who spoke to Keith Cooper for his recent non-fiction book Amazing Worlds (2025), which dedicated a chapter to such planets.

Given the frequency with which red dwarfs occur in the universe, and the close proximity of several to Earth, it appears likely that any future human exploration of our local space (superluminal, telescopic or otherwise) will involve their habitable zones. The growing detail of narratives in science fiction provide interesting thought experiments which could inform such exploration - although the capacity of the universe to surprise us will no doubt continue to confound our expectations.

Some recent examples of red dwarf system analyses at Warwick (note: added to after posting):

• Doyle et al (2024): The First Spin-Orbit Obliquity of an M dwarf/brown dwarf system: an eccentric and aligned TOI-2119 b.
• Bryant et al (2025): Discovery of Giant Planet Orbiting Tiny Star Challenges Theories on Planet Formation (press release)