Just a few weeks ago I wrote about stellar interactions, taking note of a concept advanced by scientists including Ben Zuckerman and Greg Matloff that such stars would make for easier interstellar travel. After all, if a star in its rotation around the Milky Way closes to within half a light year of the Sun, it’s a more feasible destination than Alpha Centauri. Of course, you have to wait for the star to come around, and that takes time. Zuckerman (UCLA), working with Bradley Hansen, has written about the possibility that close encounters are when a civilization will attempt such voyages.
I have a further idea along the lines of motion through the galaxy and its advantages to explorers, and it’s one that may not require tens of thousands of years of waiting. We’d like to get to another star system because we’re interested in the planets there, so what if an interstellar planet nudges into nearby space? I’ll ignore Oort Cloud perturbations and the rest to focus on a ‘rogue’ or ‘free-floating’ planet as the target of a probe, and ask whether we may not already have some of these in nearby space.
After all, finding free-floating planets – and I’m now going to start calling them FFPs, because that’s what appears in scientific papers on the matter – are hard to find. There being no reflected starlight to look for, the most productive way is to pick them out by their infrared signature, which means finding them when they’re relatively young. This is what Núria Miret Roig (University of Vienna) and team did a couple of years ago, working with data from the Very Large Telescope and other sources. Lo and behold, over one hundred FFPs turned up, all of them infants and still warm.
Image: The locations of 115 potential FFPs [free-floating planets] in the direction of the Upper Scorpius and Ophiuchus constellations, highlighted with red circles. The exact number of rogue planets found by the team is between 70 and 170, depending on the age assumed for the study region. This image was created assuming an intermediate age, resulting in a number of planet candidates in between the two extremes of the study. Credit: ESO/N. Risinger (skysurvey.org).
But young FFPs are most likely to be found in star-forming regions, two of which (in Scorpius and Ophiuchus) were subjected to Miret Roig and team’s searches. What’s likely to amble along in our rather more sedate region is an FFP with enough years on it to have cooled down. The WISE survey (Wide-Field Infrared Survey Explorer) showed how difficult it is to pin down red dwarfs in the neighborhood, although it can be done. But even there, when you get down to L- and T-class brown dwarfs, uncertainty persists about whether you can find them. With planets the challenge is even greater.
Sometimes FFPs are found through microlensing toward the galactic core, but I don’t think we can rely on that method for finding a population of such worlds within, say, half a light year. Nonetheless, Miret Roig is not alone in pointing out that “there could be several billions of these free-floating planets roaming freely in the Milky Way without a host star.” Indeed, that number could be on the low side given what we’re learning about how these objects form. Given the excitement over ‘Oumuamua and other interstellar interlopers that may appear, I’m surprised that there hasn’t been more attention paid to how we might detect planet-sized objects near our system.
The ongoing search for Planet 9 demonstrates how difficult finding a planet outside the ecliptic can be right here at home. While pondering the best way to proceed, I’ll divert the discussion to rogue planet formation, which has always been central to the debate. Are the processes rare or common, and if the latter, do most stellar systems including our own, have the potential for ejecting planets? The last two decades of study have been productive, as we have refined our methods for modeling this process.
Recent work on the Trapezium Cluster in the Orion Nebula shows us how the catalog of FFPs is growing. The Trapezium Cluster is helpfully located out of the galactic plane, and there is a molecular cloud behind it that reduces the problems posed by field stars. I was startled to learn about this study (conducted at the European Space Agency’s ESTEC facility in the Netherlands by Samuel Pearson and Mark J McCaughrean) because of the sheer number of FFPs it turned up. Some 540 FFP candidates are identified here, ranging in mass from 0.6 to 13 Jupiter masses, although the range is an estimate based on the age of the cluster and our current models of gas giant evolution.
Image: A total of 712 individual images from the Near Infrared Camera on the James Webb Space Telescope were combined to make this composite view of the Orion Nebula and the Trapezium Cluster. Credit: NASA, ESA, CSA/Science leads and image processing: M. McCaughrean, S. Pearson, CC BY-SA 3.0 IGO.
What stopped me cold about this work is that among the 540 candidate FFPs, 40 are binaries. Two free-floating planets moving together without a star, and enough of them that we have to learn a new term: JuMBOs, for Jupiter-mass binary objects. How does that happen? There are even two triple systems in the data. Digging into the paper:
…we can compare their statistical properties…with higher-mass systems. The JuMBOs span the full mass range of our PMO [planetary-mass object] candidates, from 13 MJup down to 0.7 MJup. They have evenly distributed separations between ∼25–390 au, which is significantly wider than the average separation of brown dwarf-brown dwarf binaries which peaks at ∼ 4 au [42, 43]. However, as our imaging survey is only sensitive to visual binaries with separations > 25 au, we can not rule out an additional population of JuMBOs with closer orbits. For this reason we take 9% as a lower bound for the PMO multiplicity fraction. The average mass ratio of the JuMBOs is q = 0.66. While there are a significant number of roughly equal-mass JuMBOs, only 40% of them have q ≥ 0.8. This is much lower than the typical mass ratios for brown dwarfs, which very strongly favour equal masses.
That last line is interesting. Our FFP binary systems tend to have planets of distinctly different masses, which implies, according to the authors, that if the JuMBOs formed through core collapse and fragmentation – like a star – “then there must be some fundamental extra ingredient involved at these very low masses.” But the binary systems here go well below the mass where this formation method was thought to work. That opens up the ‘ejection’ hypothesis, with the planets forming in a circumstellar disk only to be ejected by gravitational interactions. So note this:
In either case, however, how pairs of young planets can be ejected simultaneously and remain bound, albeit weakly at relatively wide separations, remains quite unclear. The ensemble of PMOs and JuMBOs that we see in the Trapezium Cluster might arise from a mix of both of these “classical” scenarios, even if both have significant caveats, or perhaps a new, quite separate formation mechanism, such as a fragmentation of a star-less disk is required.
Ejection is a rational thing to look at considering that gravitational scattering is a well-studied process and may well have occurred in the early days of our own system. On the other hand, in star-forming regions like Trapezium the nascent systems are so young that this scenario may be less likely than the core-collapse model, in which the process is similar to star formation as a molecular cloud collapses and fragments. The open question is whether a scenario like this, which seems to work for brown dwarfs, is also applicable to considerably smaller FFPs in the Jupiter-mass range.
In any case, it seems unlikely that binary planets could survive ejection from a host system. As co-author Pearson puts it, “Nine percent is massively more than what you’d expect for the planetary-mass regime. You’d really struggle to explain that from a star formation perspective…. That’s really quite puzzling.”
All of which triggered a new paper from Fangyuan Yu (Shanghai Jiao Tong University) and Dong Lai (Cornell University), which takes an entirely different tack when it comes to formation of binary FFPs:
The claimed detection of a large fraction (9 percent) of JuMBOs among FFPs (Pearson & McCaughrean 2023) seems to suggest that core collapse and fragmentation (i.e. scaled-down star formation) channel plays an important role in producing FFPs down to Jupiter masses, since we do not expect the ejection channel to produce binary planets. On the other hand, (Miret-Roig et al. 2022) suggested that the observed abundance of FFPs in young star clusters significantly exceeds the core collapse model predictions, indicating that ejections of giant planets must be frequent within the first 10 Myr of a planetary system’s life.
Yu and Lai look at close stellar flybys as a contributing factor to FFP binary formation. If we’re talking about dense young star clusters, encounters between stars should be frequent, and there has been at least one study advancing the idea that bound binary planets could be the result of such flybys. Yu and Lai model two-planet systems to study the effects of a flyby on single and double-planet systems. Will an FFP result from a close flyby? A binary FFP? Or will the flyby star contribute a planet to the system it encounters?
These numerical experiments yield interesting results: The production rate of binary pairs of FFPs caused by stellar flybys is always less than 1 percent in their modeling, even when parameters are adjusted to make for tightly packed stellar systems. Directly addressing the JWST work in Trapezium and the large number of JuMBOs found there, Yu and Lai deduce that they cannot be caused by flybys, and because ejection scenarios are so unlikely, they see “a scaled-down version of star formation” at work “via fragmentation of molecular cloud cores or weakly-bound disks or pseudo-disks in the early stages of star formation.”
The matter remains unresolved, producing much fodder for future observations and debate. And while we figure out how to detect free-floating planets that may already be far closer than Proxima Centauri, we can create science fictional scenarios of journeys not just to a single rogue planet, but to a binary or even a triple system cohering despite the absence of a central star. I can only imagine how much Robert Forward, the man who gave us Rocheworld, would have enjoyed working with that.
The paper is Pearson & McCaughrean, “Jupiter Mass Binary Objects in the Trapezium Cluster” (preprint). The Miret-Roig paper is “A rich population of free-floating planets in the Upper Scorpius young stellar association,” published online at Nature Astronomy 22 December 2021 (abstract). The Fangyuan Yu & Dong Lai paper is, “Free-Floating Planets, Survivor Planets, Captured Planets and Binary Planets from Stellar Flybys,” submitted to The Astrophysical Journal (preprint).
The simulation paper always begins with two planets in coplanar, circular orbits. It seems convincing that these don’t eject pairs of binary Jupiters, but what happens if the orbits are highly eccentric, in different planes, co-orbital from the time of formation, etc.? We should be in for some mythological naming amusement if indeed JuMBOs of a single origin cross paths, succumb to their mutual attraction, and are ejected from their systems for their illicit love. Sigmund and Signy, Phorcys and Ceto? In any case, I wonder how much tidal energy is available to moons of each planet due to their interaction with the other body: enough to power anything interesting?
Suppose that “billions of FFPs in the galaxy”= the same number of stars, how does that help with interstellar travel? The numbers suggest great distances, on average the same as other stars, so the net density increase means an average distance = 1/(2^0.333) => 0.8x the prior average stellar distance.
Secondly, do we expect FFPs to move more quickly than stellar systems? If not, the waiting times for close encounters is of comparable time to stars – longer than civilizations may last. It is like waiting for plate tectonics to move continents to allow migration. It is not the way for founder populations to radiate (c.f. the Wallace Line). I don’t even see these FFPs being useful as waystations for the refueling of worldships except in extreme circumstances. The energy to decelerate and rendezvous may be more energy-consuming than continuing to the next star system. This is very different from hopping across Oort cloud objects.
Unless FFPs have an internal heat source, they will be cold, airless worlds (if rocky) and probably just colder versions of Brown dwarfs. Interesting to study, but of little value for interstellar travel as we currently think it might progress.
Now if we get FTL travel, then they might prove a useful resource worth exploiting. OTOH, FTL travel might make these FFPs not worth the visit as more useful targets are now within easy reach.
I think FFPs become interesting as a population of objects that may be relatively near. It would be interesting to know if any are within a light year, and how many. How to find them is still a huge issue.
Last week a group at MIT managed to make a 20-tesla magnet out of high temperature superconductor. https://phys.org/news/2024-03-high-temperature-superconducting-magnets-ready.html This was an unexpectedly large advance made possible because it turns out you don’t actually have to insulate superconductors. :) As a result, nuclear fusion plants just grew noticeably larger on the horizon.
Some rogue planets might be Jupiters with a weak internal heat production and perhaps small moons with tidally heated sanctuaries, and others may be iced-over Neptunes whose oceans might not be too hot for life, but a great number of them should be garden-variety icy rocks like Pluto, covered in water, tholins, and volatile gases. Once Pluto is covered with fusion reactors and garden cities, those worlds won’t seem so unappealing, and there might be one much closer to the Sun than any other star.
Only the higher mass FFPs are detected in these young clusters. Another factor is smaller planets are more likely to be ejected than large planets.
So there is a strong possibility there are a lot more FFPs than stars, and because of that there could be some relatively nearby.
Potentially trillions rather than billions? Those interstellar freeways are going to need hazard signs. ;-)
The thought of large numbers of dark ghost planets prowling through the galaxy unnoticed suggests many interesting scenarios and possibilities. What might a close encounter with one of these worlds look like? It also implies that along with these cold planetary interlopers there may be a large number of smaller bodies with similar kinematics intermixed with them, as our own two recent extrasolar visitors have demonstrated. Its possible to speculate on the motions of these bodies by reviewing what is known about some of our stellar neighbors.
Again, I rely on the list of nearby systems published in the RASC Observer’s Handbook. Of these stars and brown dwarfs, 52 systems have published proper motions, and 40 have published radial velocities. Some of these objects may be high-velocity visitors from the galactic halo (seven have either a radial or transverse velocity component exceeding 100 km/sec), but most appear to be fellow members of the local cohort of objects drifting along with Sol in the galactic disk. The mean transverse velocity (across the line of sight) is 46 km/sec. The mean of the absolute value of the radial velocity (in the line of sight) is 35 km/sec. If these observable objects have comparable kinematics to our FFPs, then it can be expected that these invisible objects will be traveling through our neighborhood at velocities on the order of about 58 km/sec.
This number is between two and three times higher than published values for mean stellar velocities in the solar neighborhood. Why this should be so is not clear to me, but no doubt there are other factors involved I am not considering in my first order analysis. At any rate, we still are left with the conclusion that most extrasolar interlopers will be passing through at velocities comparable to those of orbital velocities of objects in the inner solar system.
Regardless of how close any of these objects approach our solar system, matching speeds with them is going to be quite outside the capability of our current propulsion technology. A collision or fly-by may be the best we can hope for.
This one’s on ArXiv:
A rich population of free-floating planets in the Upper Scorpius young stellar association
If they have moons like around jupiter such as Io where tidal energy could be used then great but other than that they would not prove useful as stop off points on interstaller journeys. Maybe a brown dwarf could be used for an oberth maneuver but I doubt a very useful one.
The FFPs might be expected to follow trajectories approximately keeping up with the herd of assorted bodies circling the galaxy; distribution of all bodien may be denser in some regions such as spiral arms. On approaching each other, mutual interactions may toss bodies randomly.
When looking for any kind of bodies, there may well be strength in numbers: “Quantity has a quality all its own”.
Since most have been ejected out of stars I am expecting a sort of diffuse halo around the gallaxy.
Hi Paul,
I wonder about the ‘moons’ of these free-floaters too. Especially the planet-size ones. If the birth environment of the FFP’s isn’t blasting all the planets with stellar winds, then primordial atmospheres might stick around. Warmed via internal decay and tidal forces, they might be warm enough for Hycean style environments to form.
What would such worlds be like? Could photosynthesis operate? Magnetic flares on brown dwarfs seem to produce significant amounts of higher frequency photons, but there’s doubtless some mass-limit to this, since neither Jupiter or Saturn show such behaviour. A binary, if orbiting close enough, might keep both objects churning enough to sustain active magnetic fields.
Many organisms can use hydrogen, rather than oxygen, as a reactive gas, but something is required to return the end-products back into reactive gases, otherwise a biosphere grinds to a halt. Geothermal energy can only do so much.
So many dark oceans might be lifeless, but they might contain strange hydrogen-powered biospheres too.
I wondered about magnetic fields in binary FFPs too, Adam. I find the idea of unusual biospheres in such places fascinating.
Hi Paul
There’s the intriguing possibility that low mass brown-dwarfs can “power-up” and start burning deuterium. Their mutual churning from tidal forces, once they’re close enough together, could provide sufficient energy to spark deuterium fusion. That’s for brown dwarfs that are initially too small to start DD fusion.
Here’s the preprint:
BD-14 3065b (TOI-4987b): from giant planet to brown dwarf: evidence for deuterium burning in old age?
The implications for orbiting planets should be obvious.
Adam, check the URL, as I can’t get it to load. I do want to read this one, and probably write about it.
Here it is, thanks to Alex:
https://arxiv.org/abs/2403.12311
Interesting! If I understand that correctly, they’ve found a 12-Jupiter-mass object which by rights ought to be a little too small to be a brown dwarf; but it has a 3520 K temperature that I think by rights could have made it a M2V red dwarf. The reason: the temperature to the 11.8 power is in the formula for how fast deuterium burning takes place. It makes me think of schlocky Hollywood adventure movies where pilferers break into some priceless old tomb and toss a torch into a trench kindly prefilled with kerosene to provide illumination. Is the universe like that, full of almost-stars that need only a little tap to turn on the lights?
I seem to recall a paper saying simulations had shown that with mass high enough to retain the H/He atmosphere, it would insulate the planet enough that even in deep space the surface might be temperate. Paul, does that sound familiar?
Assuming the ability to create a workable ecology under such circumstances, such a world could act as an ark-ship without the obvious perils of building one from scratch. Such a civilization could spread from one system to another depending on their ability to find planets heading the right direction.
Even if such worlds traveled at 100 km/s, the time to travel to nearby stars would likely be longer than the civilization existed.
However, life has existed on Earth for billions of years. Suppose that these FFPs are more common than we think today, could they be the mechanism for panspermia? If life exists on a FFP with an atmosphere, microbes could be blown off them by the star and they would seed the habitable planets downwind. So instead of isolate spores, of spores in asteroids or comments, FFPs could be huge reservoirs of life that could seed sterile systems as they passed through. With billions of years to play with, the time issue disappears and only the number of stellar system intercepts becomes relevant. The major problem with this hypothesis is that the FFP has to make a close approach to the star inside the HZ. This seems very low probability. It is enhanced if enter a multiple star system where the stars each have a retinue of planets, allowing one star to seed the planets of the other star given the large separation and no requirement for the very close approach.
Prediction: If panspermia is the dominant form of the origin of life on worlds, multiple-star systems will be more likely to have life than single-star systems like our own system.
How much microbial mass, if any, is stripped off Earth’s atmosphere and deposited in space? We should know that before speculating about other, unknown planets. That’s the only data we can collect at the moment.
@Ron S.
AFAIK, all we know are 2 things.
1. bacteria and spores can be found in the atmosphere as high as we have looked.
2. bacterial and fungal spores do survive in space.
But idk of any data from satellites used to detect micrometeroids that indicates whether any spores were detected, and if there were, how frequently. It might be in any range from zero upwards. I would note that Zubrin has stated that Mars would have been seeded by terrestrial bacteria for eons, so we don’t need to worry about terrestrial contamination of Mars by astronauts. Does he have knowledge, or is just BSing to support his position on Mars colonization?
“Does he have knowledge…”
Clearly not since there is no evidence of it. It’s speculation, perhaps in service to his ambitions, or at best a possibly testable hypothesis. In any case, any microbes that do land on Mars are unlikely to do more than lie there until they decay.
@Alex T
I retract the idea. It seems to me that the number of FFPs would have to be very much greater than the star population by at least several orders of magnitude. The lack of brown dwarfs would seem to dismiss that option for planets forming from gas clouds. Even if all the stars shed their planets, it seems doubtful that FFPs could be more numerous than 1 order of magnitude than stars.
A star with a retinue of planets is better situated to blow off spores from a habitable world in its system and potentially seed a planet in another system. The frequency of close intercepts over time would seem to be important if this was the case.
Back in 2019, Greg Matloff examined what might be causing the excess velocity of older, low-mass stars – the Parenago effect. It occurs to me that these stars might be more important in any panspermia effect if their higher velocity increased their rate of encounters with other stars. Idk if it has been determined if this is a galaxy-wide effect or relatively local, but it does make for interesting speculation as to whether this is not a natural effect but deliberate, and possibly designed to increase the spread of life over billions of years. Regardless, if a red dwarf with a living world is stable for 100 bn years, that is around 400 galactic rotations. How many stars would a faster-moving RD star intercept in that time, possibly spreading bacterial life?
Is panspermia a non-starter if we fail tu find life on Mars?
@Tesh
That is a good question. I would say that if there was no evidence that Mars ever had life that could be linked to Earth (or Venus), then it certainly reduces the probability. Of course, our life could be due to panspermia from early Venus or Mars. So we need to know if there is any extant or extinct life on these planets that can be linked to terrestrial life. Europa might be an outside candidate.
Personally, I would hope that abiogenesis is common, rather than panspermia because that would probably demonstrate a greater biological diversity and be scientifically far more interesting. Therefore finding evidence of life on exoplanets is a first step. How we can be sure of abiogenesis vs panspermia is unclear without taking samples of life and analyzing that life.
Paul Davies’ hypothesis of a “shadow biosphere” on Earth would also be very interesting for a similar reason, although there is no sign of one so far despite his group’s searches. My guess that if there were different abiogenesis events on Earth, our lineage drove any others to extinction. They would probably be forced into refuges that are inhospitable to our life. As we have barely explored the crustal biosphere, that may be a possible refuge.
[We should also remind ourselves that only a fraction of Earth’s species have been discovered, especially bacteria and fungi. Finding a “shadow lifeform is very difficult. How does one even go about it if it is very different?]
The large numbers of suspected FFPs should not be too surprising. Although the stellar mass function for sub-stellar objects is not well established, we do know that the number of objects grows explosively as stellar mass decreases. Although the formation of large planet-sized objects may be the result of different processes than that of small stars and brown dwarfs, it is not unreasonable to believe that they may outnumber stars, especially when one considers planetary system objects ejected by their stars. And if they have retinues of satellites like our gas giants…the mind boggles.
The proportional mass of the galaxy contributed by these objects may still be quite small, but if there are large enough numbers of them, it might make up for that. Maybe these are the missing MACHOs everyone has been looking for?
With a long term source of internal energy like tidal heating or isotopes suitable for nuclear reactions, and with abundant geological resources, these objects may be a form of generational ship capable of supporting large populations for long periods. A good way to escape a dying system, or perhaps to hide from a hostile enemy. Sure, they may be slow, but maybe there’s no particular need to get anywhere in a hurry.
If nothing else, these ‘wanderers’ provide a fertile field for fiction. πλανήτης indeed!
“The proportional mass of the galaxy contributed by these objects may still be quite small, but if there are large enough numbers of them, it might make up for that. Maybe these are the missing MACHOs everyone has been looking for?”
No. Micro-lensing surveys are pretty conclusive that there are not nearly enough of these objects in our galaxy (or micro-BH, BD, etc.) to account for the “missing” mass.
Free floating exoworlds are not the only loose objects lurking about our galaxy…
https://news.berkeley.edu/2022/06/10/astronomers-may-have-detected-a-dark-free-floating-black-hole/
https://arxiv.org/abs/1907.00792
The above paper from 2019 estimates there are approximately 100 million black holes currently roaming our stellar island amongst its 400 billion star systems. I wonder how much that number has changed if anyone has attempted to revise it since?
We can also assume there are plenty of moons, comets, asteroids, meteoroids, and who knows what else in this club as well. Perhaps interstellar space is not quite as empty as we assume.
Could a Self-Sustaining Starship Carry Humanity to Distant Worlds?
Generation ships offer a tantalizing possibility: transporting humans on a permanent voyage to a new home among the stars.
https://thereader.mitpress.mit.edu/could-a-self-sustaining-starship-carry-humanity-to-distant-worlds/
“The only barrier to human development is ignorance, and this is not insurmountable.” —Robert Goddard
Excerpted from this book:
https://mitpress.mit.edu/9780262543842/the-next-500-years/
https://www.scientificamerican.com/article/orions-twin-rogue-planets-inexplicably-blaze-with-intense-radio-waves/
MARCH 19, 2024
Orion’s Twin Rogue Planets Inexplicably Blaze with Intense Radio Waves
Researchers don’t know how this pair of free-floating planets formed or why it radiates so brightly.
BY JOSEPH HOWLETT
Strange, twirling duos of roughly Jupiter-size celestial bodies in the Orion Nebula have had astronomers scratching their heads since the James Webb Space Telescope (JWST) photographed them in October 2023. Unless they were violently ejected from a solar system—unlikely, given their delicate, undisturbed dance—the free-floating pairs challenge astronomers’ long-standing notion that planets can form only within a star’s orbit.
Researchers have now discovered radio-wavelength signals from one of these 42so-called Jupiter-mass binary objects (JuMBOs), according to a study in the Astrophysical Journal Letters, suggesting the pair is astoundingly bright. “It’s important to understand what these objects are, and having radio data really adds a new dimension to the problem,” says the study’s lead author, Luis F. Rodríguez, an astronomer at the National Autonomous University of Mexico.
When Rodríguez and his team heard about JWST’s discovery, they scoured public telescope data for unidentified radio-wave sources in Orion and found one that recurred three times over a decade in the exact same position as the pair known as JuMBO24. The signals suggest JuMBO24 isn’t moving quickly through the nebula, which would mean it might have indeed been born alone rather than blasted away from a star system.
“The Orion Nebula is just so far away that I would never have expected there to be detectable radio emission,” says Melodie Kao, a planetary radio expert at the University of California, Santa Cruz, who was not part of the team. Large planets’ magnetic fields can capture electrons, building up a carousel of electricity that zips around their equators and beams out radio waves like an antenna. But it would take unprecedented power for JuMBO24’s signal to reach Earth. “This JuMBO would have to be extraordinarily bright—100 times brighter than anything we’ve ever seen,” Kao says. If confirmed, this attribute would make JuMBOs even more baffling because no ordinary planet’s magnetic field can sustain such a dazzling glow.
“I don’t think the last word has been spoken on this, but it’s a really intriguing paper,” says Jan Forbrich, an astronomer at the University of Hertfordshire in England. Forbrich was not involved in this study, but his 2012 discovery of the then unidentified radio source in Orion made it possible. Both he and Kao hope to see further radio surveys of this and other JuMBOs to confirm their status as powerful radio sources.
Rodríguez agrees that more radio telescopes should tune in to Orion’s station. He says JuMBOs may add to our understanding of where planets come from and how many there are. If such pairs can really form without a host star, he says, “it means there are probably a zillion planets in our own galaxy that we haven’t accounted for.”
A zillion, sir?
The paper here:
https://iopscience.iop.org/article/10.3847/2041-8213/ad18ac
Where Are All These Rogue Planets Coming From?
There’s a population of planets that drifts through space untethered to any stars. They’re called rogue planets or free-floating planets (FFPs.) Some FFPs form as loners, never having enjoyed the company of a star. But most are ejected from solar systems somehow, and there are different ways that can happen.
One researcher set out to try to understand the FFP population and how they came to be.
FFPs are also called isolated planetary-mass objects (iPMOs) in scientific literature, but regardless of what name’s being used, they’re the same thing. These planets wander through interstellar space on their own, divorced from any relationship with stars or other planets.
Full article here:
https://www.universetoday.com/166406/where-are-all-these-rogue-planets-coming-from/