Planetary bodies observed for first time in habitable zone of dead star

A ring of planetary debris studded with moon-sized structures has been observed orbiting close to a white dwarf star, hinting at a nearby planet in the “habitable zone” where water and life could exist, according to a new study led by UCL researchers.


Peer-Reviewed Publication

UNIVERSITY COLLEGE LONDON

Habitable zone planet orbiting white dwarf star
IMAGE: AN ARTIST’S IMPRESSION OF THE WHITE DWARF STAR WD1054–226 ORBITED BY CLOUDS OF PLANETARY DEBRIS AND A MAJOR PLANET IN THE HABITABLE ZONE. view more  CREDIT: CREDIT: MARK A. GARLICK / MARKGARLICK.COM.

Planetary bodies observed for first time in habitable zone of dead star

A ring of planetary debris studded with moon-sized structures has been observed orbiting close to a white dwarf star, hinting at a nearby planet in the “habitable zone” where water and life could exist, according to a new study led by UCL researchers.

White dwarfs are glowing embers of stars that have burned through all their hydrogen fuel. Nearly all stars, including the Sun, will eventually become white dwarfs, but very little is known about their planetary systems.

In the study, published in Monthly Notices of the Royal Astronomical Society, an international team of researchers measured light from a white dwarf in the Milky Way known as WD1054–226, using data from ground- and space-based telescopes.

To their surprise, they found pronounced dips in light corresponding to 65 evenly spaced clouds of planetary debris orbiting the star every 25 hours. The researchers concluded that the precise regularity of the transiting structures – dimming the star’s light every 23 minutes – suggests they are kept in such a precise arrangement by a nearby planet.

Lead author Professor Jay Farihi (UCL Physics & Astronomy) said: “This is the first time astronomers have detected any kind of planetary body in the habitable zone of a white dwarf.

“The moon-sized structures we have observed are irregular and dusty (e.g. comet-like) rather than solid, spherical bodies.  Their absolute regularity, one passing in front of the star every 23 minutes, is a mystery we cannot currently explain.

“An exciting possibility is that these bodies are kept in such an evenly-spaced orbital pattern because of the gravitational influence of a nearby planet. Without this influence, friction and collisions would cause the structures to disperse, losing the precise regularity that is observed.  A precedent for this ‘shepherding’ is the way the gravitational pull of moons around Neptune and Saturn help to create stable ring structures orbiting these planets.

“The possibility of a planet in the habitable zone is exciting and also unexpected; we were not looking for this.  However, it is important to keep in mind that more evidence is necessary to confirm the presence of a planet. We cannot observe the planet directly so confirmation may come by comparing computer models with further observations of the star and orbiting debris.” 

It is expected that this orbit around the white dwarf was swept clear during the giant star phase of its life, and thus any planet that can potentially host water and thus life would be a recent development.  The area would be habitable for at least two billion years, including at least one billion years into the future.

More than 95% of all stars will eventually become white dwarfs. The exceptions are the largest stars that explode and become either black holes or neutron stars.

Professor Farihi added: “Since our Sun will become a white dwarf in a few billion years, our study provides a glimpse into the future of our own solar system.”

When stars begin running out of hydrogen, they expand and cool, becoming red giants. The Sun will enter this phase in four to five billion years, swallowing Mercury, Venus, and possibly Earth. Once the outer material has gently blown away and hydrogen is exhausted, the hot core of the star remains, slowly cooling over billions of years – this is the star’s white dwarf phase.

Planets orbiting white dwarfs are challenging for astronomers to detect because the stars are much fainter than main-sequence stars (like the Sun). So far, astronomers have only found tentative evidence of a gas giant (like Jupiter) orbiting a white dwarf.

For the new study, researchers observed WD1054–226, a white dwarf 117 light years away, recording changes in its light over 18 nights using the ULTRACAM high-speed camera fixed on to the ESO 3.5m New Technology Telescope (NTT) at the La Silla Observatory in Chile. In order to better interpret the changes in light, the researchers also looked at data from the NASA Transiting Exoplanet Survey Satellite (TESS), which allowed the researchers to confirm the planetary structures had a 25-hour orbit.

They found that the light from WD1054–226 was always somewhat obscured by enormous clouds of orbiting material passing in front of it, suggesting a ring of planetary debris orbiting the star.

The habitable zone, sometimes called the Goldilocks zone, is the area where the temperature would theoretically allow liquid water to exist on the surface of a planet.  Compared to a star like the Sun, the habitable zone of a white dwarf will be smaller and closer to the star as white dwarfs give off less light and thus heat.

The structures observed in the study orbit in an area that would have been enveloped by the star while it was a red giant, so are likely to have formed or arrived relatively recently, rather than survived from the birth of the star and its planetary system.

The study received funding from the UK’s Science and Technology Facilities Council (STFC) and involved a team of researchers from six countries, including Boston University, the University of Warwick, Lund University, the University of Cambridge, the University of St Andrews, Wesleyan University, the University of La Laguna, Naresuan University, the University of Sheffield, and the Instituto de Astrofísica de Canarias.


JOURNAL

Monthly Notices of the Royal Astronomical Society

DOI

10.1093/mnras/stab3475 

METHOD OF RESEARCH

Data/statistical analysis

ARTICLE TITLE

Relentless and Complex Transits from a Planetesimal Debris Disk’

ARTICLE PUBLICATION DATE

11-Feb-2022

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February 12, 2022 3:51 am

“The moon-sized structures we have observed are irregular and dusty (e.g. comet-like) rather than solid, spherical bodies. Their absolute regularity, one passing in front of the star every 23 minutes, is a mystery we cannot currently explain.

Rocketscientist
Reply to  zee raja
February 12, 2022 8:53 am

I wonder what alien astronomers would say about our asteroid belt?
Perhaps something like: Irregular, dusty, very few spherical bodies, passing in front of the star at regular intervals?
… a mystery we cannot currently explain.

Tom Abbott
Reply to  zee raja
February 12, 2022 4:09 pm

I would think if they are moon-sized bodies (I’m assuming they mean the Earth’s moon) then they should be spherical bodies if they are that big.

Richard Page
February 12, 2022 4:00 am

More data means that the ‘rules’ of celestial mechanics are constantly changing – the idea that a planet could exist in the Inner system of a white dwarf would have been unthinkable before these observations. Could a planet actually form after the star collapses, or is this a wanderer that’s found a new stable orbit? Fascinating stuff.

beng135
Reply to  Richard Page
February 13, 2022 9:16 am

I think there is good evidence that it has happened in very rare instances from debris that was blown away some distance, then falling back and reforming around a white dwarf. But pretty obviously there wouldn’t be any life left….

Last edited 3 months ago by beng135
fretslider
February 12, 2022 4:05 am

So, Dark Star didn’t take them out

Gordon A. Dressler
Reply to  fretslider
February 12, 2022 8:08 am

Errrrr . . . did you mean “Death Star”?

Erik Magnuson
Reply to  Gordon A. Dressler
February 12, 2022 10:09 am

I’m pretty sure he meant “Dark Star”.

fretslider
Reply to  Erik Magnuson
February 12, 2022 11:55 am

I did

Gordon A. Dressler
Reply to  fretslider
February 12, 2022 12:46 pm

Well then, my apologies.

The starship Dark Star in the 1974 science fiction comedy film had the mission to destroy unstable planets that might threaten future colonization of other planets.

The data presented in the above article mentioned nothing about mankind intending colonize the space around the white dwarf WD1054–226.

Mea culpa.

Edim
February 12, 2022 4:31 am

“There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.”

AWG
February 12, 2022 5:30 am

Let this be a lesson to you all you Climate Deniers® that if you don’t mend your ways and devote your life to privation and fear, then not only will your planet shrapnel, but you will also kill the sun.

Last edited 3 months ago by AWG
Reply to  AWG
February 12, 2022 5:39 am

I hope you only forgot the /sarc 😀

AWG
Reply to  Krishna Gans
February 12, 2022 5:43 am

You may be right; Poe’s Law pretty much requires sarcasm to be clearly labeled now.

H.R.
Reply to  AWG
February 12, 2022 7:21 pm

You forgot the winky, AWG.
😉

amike
February 12, 2022 6:04 am

and thus any planet that can potentially host water and thus life would be a recent development. “
Life ? Fromwhere ? Planet had been ionised, externals comets withs complex structures pushed back… This is exactly the situation seen in Interstellar : a planet with water but sterilized, too clean…

Ruleo
Reply to  amike
February 12, 2022 11:23 am

Mann’s Planet!

Duane
Reply to  amike
February 12, 2022 11:29 am

All it takes is carbon, one of the most abundant elements in the universe, along with water, also abundant, on a rocky planet in the habitable zone. Space debris including asteroids and comets colliding with the planet is how earth, at one time an inhospitable rock with no carbon or water, gained life.

Bruce Cobb
February 12, 2022 6:54 am

The white star dwarf WD40 is easily recognizable, due to its logo.

Bryan A
Reply to  Bruce Cobb
February 12, 2022 7:14 am

That White Dwarf wouldn’t have anything orbiting thanks to liberal amounts of the lubricant.

Last edited 3 months ago by Bryan A
Gordon A. Dressler
Reply to  Bruce Cobb
February 12, 2022 8:11 am

Heck, it’s even a slippery object to catch in a telescope.

Last edited 3 months ago by Gordon A. Dressler
beng135
Reply to  Bruce Cobb
February 13, 2022 9:39 am

Hope it doesn’t have any rubber planets — WD40 dissolves rubber.

Sara
February 12, 2022 7:04 am

Finally, there’s a place to send politicians to when they get too self-important!!! (sarc)

What? It’s juts an idea, y’know.

Gordon A. Dressler
February 12, 2022 8:06 am

Excuse my nit-picking about the above article, but I believe the word “observed” his been misused repeatedly in the above article.

A careful read of the article shows that the only observation made was that of “measured light from a white dwarf in the Milky Way known as WD1054–226 . . . (having) . . .
pronounced dips in light corresponding to 65 evenly spaced clouds of planetary debris orbiting the star every 25 hours . . . (from which) . . . researchers concluded that the precise regularity of the transiting structures – dimming the star’s light every 23 minutes – suggests they are kept in such a precise arrangement by a nearby planet.”

No planet was observed directly and no “ring of planetary debris studded with moon-sized structures “ was observed directly.

Personally, I wish our telescopes (ground- or space-based) had the resolution necessary for such direct observations at such distances, but the laws of diffraction physics coupled with manufacturing limitations say it just ain’t possible.

noaaprogrammer
Reply to  Gordon A. Dressler
February 12, 2022 9:52 am

I know that the James Webb telescope that is currently being readied for use specializes in infrared frequencies, which won’t help in any direct observation either.

Duane
Reply to  Gordon A. Dressler
February 12, 2022 11:31 am

A reduction of light observed on a distant star is a direct observation of a planet or other orbiting solid matter. It IS observed, not modeled or theorized.

Gordon A. Dressler
Reply to  Duane
February 12, 2022 12:27 pm

Duane,

That is the very first time I have seen such an explanation offered for the light variation coming from stars known as “Cepheid variables”.

You should publish on this.

Last edited 3 months ago by Gordon A. Dressler
Kip Hansen(@kiphansen2)
Editor
February 12, 2022 8:06 am

The astronomers did NOT OBSERVE planetary bodies — the recorded “pronounced dips in light” from a star that is 117 light years away with entirely unknowable amounts of “stuff” between the star and the observers.

“The moon-sized structures we have observed are irregular and dusty (e.g. comet-like) rather than solid, spherical bodies.” An astronomer’s Just So story….. they did not observe any such thing — they speculate that if the signal is planetary-moon-like bodies that they might be dusty —

Einstein’s shoes might have been dusty the day he first formulated the theory of general relativity. Same amount of evidence.

Last edited 3 months ago by Kip Hansen
Duane
Reply to  Kip Hansen
February 12, 2022 11:43 am

Bullshit.

Observations of regular changes in light observed from a distant star most certainly IS a direct observation of orbiting planets and/or other rocky masses in orbit around the star. It is just as direct an observation as anything else that can be “seen” by the human eye, or by a telescope, or by any other remote sensor.

Geez, where do you get such nonsense?

Gordon A. Dressler
Reply to  Duane
February 12, 2022 12:35 pm

Speaking of nonsense,

Is the observation of an apple falling from a tree equivalent to observation of gravity (i.e., gravitons or gravity waves)?

Or, is the seeing the absence of the sunshine in the darkness of night equivalent to an observation that the Sun has ceased to exist?

Reading the definition of “inference” and its distinction from “observation” will greatly assist in eliminating the aforementioned nonsense.

Kip Hansen(@kiphansen2)
Editor
Reply to  Duane
February 12, 2022 6:39 pm

Duane ==> “I Want to Believe” — Mulder

MarkMcD
Reply to  Duane
February 13, 2022 4:49 pm

Observations of regular changes in light observed from a distant star most certainly IS a direct observation of orbiting planets and/or other rocky masses in orbit around the star

Nope. It is literally the direct observation of “of regular changes in light” – it might be a lot of things, including aliens and the fact those changes are so regular would lean more to aliens than 65 objects randomly but perfectly placed in the exact same orbit.

MarkW
February 12, 2022 9:11 am

If the planet is in the habitable zone of a white dwarf, that means the planet was inside the star when it was in the red giant phase. Which means that the planet has no water and no air. The chances of there being life on that planet is zero.

Richard Page
Reply to  MarkW
February 12, 2022 9:51 am

Or it formed after the star collapsed, it that’s possible, or a wanderer getting caught in the inner system. How old is the star and how long ago did it collapse?
Frankly, unless the planet was at the outer edge of the expanded star, it wouldn’t just be irradiated, it wouldn’t have survived – that’s probably what the dusty, rocky stuff is around the star; the former inner system planet’s.

MarkW
Reply to  Richard Page
February 12, 2022 3:45 pm

Planets form in the same orbit as the material they are built from. That orbit was inside the red giant, and would be completely devoid of any of the lighter elements.

Duane
Reply to  MarkW
February 12, 2022 11:36 am

No – once the star enters its red giant stage, it consumes and destroys any planets within the radius of the surface of the red giant, and also causes huge changes in the gravitational field around the star in more distant orbits. Thus planets in more distant orbits can change their orbits, or other objects like asteroids and planetoids and planetesimals can coalesce into new rocky planets that can then end up within the habitable zone of the eventual white dwarf.

Last edited 3 months ago by Duane
Richard Page
Reply to  Duane
February 12, 2022 12:37 pm

See, you said no to begin with, then you went on to agree with what I was saying. I find it hard to take any of your posts seriously when you can’t decide on whether you agree or disagree with a previous post.
Now, here’s the thing – we both agree that the star expanded into a giant, or supergiant, destroying or pulverising anything in or near to it in the Inner system, don’t we? Would there have been enough debris left to form an accretion disc for a new planet plus the ring(s) that are still in evidence, or could a planet (or more than 1) have been ‘pulled’ into an inner system orbit from the outer system?

Dudley Horscroft(@dudleyhorscroft)
Reply to  Richard Page
February 13, 2022 1:09 am

What is the temperature of the outer layer of a red giant? If equal to the temperature at which iron shines red, then it is likely that any planet inside the edge of the RG would have been vaporized, or at least melted and disassociated into droplets.

I have another question – if the material has a period of 25 hours, and is supposed to be 65 “thingies” then is it not possible that what they are observing is the reduction of light from a ‘Planet’ with an orbit of 23 minutes. Sounds much more likely than 65 ‘thingies’ exactly equally spaced in orbit.

There is just the possibility that some alien civilization has put 65 space stations into orbit around this star.

I do object to the title stating “Dead” star. This is a white dwarf and will be radiating for many millions of years. Not Dead Yet!

Richard Page
Reply to  Dudley Horscroft
February 13, 2022 6:17 am

I don’t think that’s what they’re saying – I think they’re indicating that they’re seeing regular ‘clumps’ or thicker areas of debris with thinner, less cluttered areas between. The theory being that gravitational attraction from another body in the Inner system is causing this effect on a debris ring, causing it to ‘clump’ up – dimming and brightening on a regular cycle rather than a clearly defined ‘on/off’ change in brightness caused by a planet moving in front of the star.. The presence of a planet is implied by the theory but not by direct observation, as others have pointed out.

Richard Page
Reply to  Richard Page
February 13, 2022 6:25 am

Also, any planet caught in the perimeter of the expanding giant star is likely to be torn apart before the heat would melt it – chances are that some of the debris was left behind when the star collapsed or was just outside the star’s perimeter. I agree that any debris caught inside the star’s perimeter would have been vapourised but quite a lot may have survived to form a debris ring.

Last edited 3 months ago by Richard Page
beng135
Reply to  MarkW
February 13, 2022 9:42 am

Yeah I’d have to agree. Rocky material might survive and fall back, even reform, but water is long gone. Maybe silicon creatures like in Star Trek? 🙂

Ruleo
February 12, 2022 11:21 am

Nope.

Matt Kiro
February 12, 2022 12:56 pm

Unless one of these planets in the habitable zone has a similar moon to the one around Earth, I wouldn’t waste time and keep on searching.

Slowroll
February 12, 2022 3:44 pm

As an engineer, I find this sort of stuff interesting, but I must say that it seems like a colossal waste of money to spend on fabulously expensive equipment to satisfy curiosity that we can do nothing with. Better all that money be used to work on fusion and improved fission reactors to help an energy issue that we need solved, and maybe silence all the climastrologists (assuming they really want truly renewable and unlimited energy based on E=MC²)

beng135
Reply to  Slowroll
February 13, 2022 9:44 am

Meh. Trillions are wasted all the time — what’s a few hundred million or even a couple billion to at least do something arguably useful.

Last edited 3 months ago by beng135
Slowroll
Reply to  beng135
February 13, 2022 10:28 am

Arguably being the operative word. Few billion here, few billion there,pretty soon we’re talking real money– Everett Dirksen, late senator.

Mike McMillan
February 12, 2022 3:58 pm

Ringworld.

Richard Page
Reply to  Mike McMillan
February 12, 2022 5:49 pm

More like a Klemperer Rosette.

MarkMcD
February 13, 2022 4:35 pm

To their surprise, they found pronounced dips in light corresponding to 65 evenly spaced clouds of planetary debris orbiting the star every 25 hours. The researchers concluded that the precise regularity of the transiting structures – dimming the star’s light every 23 minutes – suggests they are kept in such a precise arrangement by a nearby planet.

I’m not an astronomer but it seems to me these 2 data are incompatible with the idea of a planet shepherding rings.

If the 65 objects are passing so regularly, they are in the same orbit! I think they need a new explanation that might put 65 ‘moons’ into the same orbit – which seems so odd as to be not a feasible natural event.

They found that the light from WD1054–226 was always somewhat obscured by enormous clouds of orbiting material passing in front of it, suggesting a ring of planetary debris orbiting the star.

So the ring(s) of matter are NOT the 65 mentioned above, or at best, the 65 are clumps of density within the rings, which is STILL a problem as far as I can work out.

How do you get 65 solid bodies in such sync. And if they are part of the ring(s) you’d expect collisions and/or the presence of a planet would have disrupted the perfect ‘1 every 23 minutes’ wouldn’t you?

MarkMcD
February 13, 2022 5:00 pm

I have some questions on this.

  1. Would a red giant actually destroy rocky planets? Space.com says temps are around 2200°C so yes it would heat the planet to untenable levels but would even melting the surface, no matter how deep, actually destroy the planet?
  2. I’m not sure of the physics but would the expansion actually gavitically disturb outer orbits? The centre of gravity is still the centre of the system so while those close in would experience a difference because mass has moved out around them, but wouldn’t outer planets ‘mass pointer’ (don’t blame me, others brought up Niven’s ideas 😀 ) still be to the centre of the system and so their orbits be the same?
Last edited 3 months ago by MarkMcD
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