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Volunteers spot almost 100 cold brown dwarfs near our sun
- LatteLazy 6y agoNear? (I read the article, it also seems not to know any actual distances).
- PenisBanana 6y agoOn the very final page is a table of distances. From 8 parsec to 70 parsec, so 28 to 250 light years or 240 trillion kms to 2170 trillion kms away (-ish) Many are comparatively cold. While most seem to be 400 Celsius plus, one (couldn't find in the article, but mentioned elsewhere) seemed to be -10 Celsius. Roughly (waving my hands and talking vaguely here) about 10% plus minus in distance and temperature.
- etangent 6y agoSo that's actually further away than the closest star systems. Got freaked out for a second, because having hard-to-see massive objects near your sun system is scary!
- mynegation 6y agoNearest known brown dwarf (actually a binary) Luhman-16 is farther away than Proxima but not by much (relatively speaking). It would be interesting to know if a theoretical smallest coolest brown dwarf would be detectable with the current technology.
- skykooler 6y agoThe line between small brown dwarfs and large planets is blurry. A brown dwarf twice the size of Jupiter and twelve times its mass could probably get inside our Oort cloud and have evaded detection.
- garmaine 6y agoWhy would it be scary?
- ivalm 6y agoIf a brown dwarf scatters into the solar system it might dramatically shift orbits potentially making earth uninhabitable. To say nothing of a direct hit on anything, even hitting the sun might strip atmosphere from earth, hitting any planet would create world ending debris fields
- jvm___ 6y agoBecause eventually that body would have gravitational effects on our stable system and could throw everything out of whack.
- garmaine 6y agoIf it were in our solar system then it would be in a gravitationally stable arrangement--because if it weren't it would have already thrown things out of whack in the last 4.5 billion years.
- kabdib 6y agoThe solar system is actually not stable in the long term. Early planetary development was violent and chaotic, and the planets shifted around a lot more than you might think. We can't project orbits out indefinitely, either; multiple studies show that our ability to go out more than a few hundred million years are suspect and very dependent on starting conditions, which can obviously be easily perturbed by unknown bodies. Since we get star-sized approaches at Oort Cloud distances on the order of every few million years, that probably puts an upper bound on things.
- btilly 6y agoOur next such approach is https://en.wikipedia.org/wiki/Gliese_710 https://en.wikipedia.org/wiki/Gliese_710 in 1.281 million years. However the rate at which such encounters happen varies greatly. We are in an orbit bobs up and down from the galactic ecliptic with a period of roughly 60 million years. There are more encounters near the ecliptic, with very few encounters when we are above or below. We cross the ecliptic about every 30 million years, and last did so about 3 million years ago. So we are still in the dangerous period. It is not entirely a coincidence that the dinosaurs were wiped out 66 million years ago, during another relatively dangerous period.
- throwaway316943 6y agoDon’t worry, there could still be somewhat smaller less detectable objects nearby.
- eloff 6y agoIt's amazing that we could detect an object that cold, that small, at those distances. How does that work?
- doctoboggan 6y agoFrom my understanding they took 2 pictures of the same spot at different times and then had volunteers (“citizen scientists”) look at those pictures to see if anything moved. You can see some examples of the kinds of pictures in the paper linked in another comment above.
- unzadunza 6y agoI had to look it up, because I'm curious too. It looks like volunteers are given images from NASA's Wide-field Infrared Survey Explorer (WISE) telescope. The volunteers then just look for moving objects. https://www.zooniverse.org/projects/marckuchner/backyard-worlds-planet-9/about/research https://www.zooniverse.org/projects/marckuchner/backyard-wor...
- nitrogen 6y agoI was unable to find a table matching wavelengths to visible temperatures in a bit of searching. Closest I could find is the chromaticity diagram on Wikipedia's Black-body Radiation article, which puts 1000K around 0.7nm red light. The WISE article lists 22μm as its longest wavelength, though that might no longer be attainable since WISE is out of coolant. If one can find out what blackbody temperature has its peak at 22μm, then we could maybe see how close to the edge of WISE's temperature range the 400C (673K) and -10C (263K) dwarves are. https://en.m.wikipedia.org/wiki/Wide-field_Infrared_Survey_Explorer https://en.m.wikipedia.org/wiki/Wide-field_Infrared_Survey_E... ---- Edit: found it: https://commons.m.wikimedia.org/wiki/File:Blackbody_peak_wavelength_exitance_vs_temperature.svg https://commons.m.wikimedia.org/wiki/File:Blackbody_peak_wav... Looks like 20μm is a bit below 200K, so if I'm interpreting this right, WISE should have had no temperature-related problem (leaving aside brightness) spotting a -10C brown dwarf.
- eloff 6y ago
- messe 6y ago> From 8 parsec to 70 parsec Really minor correction, but 7.1±1.4 is the lower bound. 1 parsec is a tad over 3 lightyears, so it's a somewhat significant difference when the distances are that small. EDIT: corrected my correction
- PenisBanana 6y agoAh, yes. A parsec is about 3.3 light years. I misremembered as 3.7 or 3.8 light years.
- Someone 6y agohttps://www.nationalastro.org/news/cool-new-worlds-found-in-our-cosmic-backyard/ https://www.nationalastro.org/news/cool-new-worlds-found-in-... tries to hide it, too, but says, in note 1: The closest of these new discoveries is roughly 23 light-years away from the Sun. Many more of these brown dwarfs are in the 30–60 light-year distance range.
- sudoaza 6y agoPff since the closest star system is just 4ly away I was expecting something closer...
- Robotbeat 6y agoThere may still be some cold brown dwarf nearer than Proxima.
- deleted 6y ago[deleted]
- catmistake 6y agohttps://en.wikipedia.org/wiki/Nemesis_(hypothetical_star) https://en.wikipedia.org/wiki/Nemesis_(hypothetical_star)
- zipwitch 6y agoAs the wikipedia article states, the WISE survey[1] results would have turned up Nemesis or anything like it, and did not. Currently most likely theory for the improbable distribution of objects beyond the Kuiper Cliff is Planet Nine.[2] [1]https://en.wikipedia.org/wiki/Wide-field_Infrared_Survey_Explorer https://en.wikipedia.org/wiki/Wide-field_Infrared_Survey_Exp... [2]https://en.wikipedia.org/wiki/Planet_Nine https://en.wikipedia.org/wiki/Planet_Nine
- deleted 6y ago[deleted]
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- ErikVandeWater 6y agoI find the phrasing odd as well. Why specify near our sun as opposed to near us? If it's specifically near our sun as opposed to near us that would imply something closer to the sun than us.
- jessaustin 6y agoThey're trying not to sound provincial, to the many scientists based in other solar systems who will read this paper in centuries to come.
- adrianmonk 6y agoMaybe, but I'm not sure how "our sun" is less provincial than "us".
- repsilat 6y agoThey should have said "near Mars", it would have been more exciting.
- adrianmonk 6y agoThey could have also gone with near Topeka, Kansas.
- rement 6y agoSpace.com likes to write those kind of titles. However, the observable universe is ~93 billion lights years[0] across so 20-60 light years is relatively close. [0] https://en.wikipedia.org/wiki/Observable_universe https://en.wikipedia.org/wiki/Observable_universe
- dghughes 6y agoSame here. For a second I thought they literally meant objects close to and orbiting our Sun. And Fahrenheit on a science website? Use kelvin or at least Celsius not Fahrenheit. What an annoying article.
- scruffyherder 6y agoYeah, it makes it sound like they are in the solar system.
- 8bitsrule 6y agoMy first reaction when I saw the headline was NEAR THE SUN. As in, Mercury near. As in 'near-sun-objects'. TA mentions no distances. Even 1 to 10 LY away (1/4 to twice as far as Proxima) ... is not so 'near'. If we use Pluto's orbital diameter as that of the solar system, then it's only about .001 light-years. 'Backyard'? If my backyard is 100 feet long, a thousand of those is 19 miles.
- sradman 6y agoThe paper Spitzer Follow-up of Extremely Cold Brown Dwarfs Discovered by the Backyard Worlds: Planet 9 Citizen Science Project [1]: > We present Spitzer follow-up imaging of 95 candidate extremely cold brown dwarfs discovered by the Backyard Worlds: Planet 9 citizen science project, which uses visually perceived motion in multi-epoch WISE images to identify previously unrecognized substellar neighbors to the Sun. [1] https://arxiv.org/abs/2008.06396 https://arxiv.org/abs/2008.06396
- throwaway2048 6y agoShould be noted that this kind of science in particular will be completely destroyed from satellite constellation launches from the likes of SpaceX and Blue Origin. https://phys.org/news/2020-05-costly-collateral-elonmusk-starlink-satellite.html https://phys.org/news/2020-05-costly-collateral-elonmusk-sta... With the amount of satellites being launched, it will be impossible not to have several in frame, especially over a long exposure, and they will swamp out pretty much any signal from space with their brightness.
- cookingrobot 6y agoYou don’t need long exposure now that we have digital cameras, it’s better to stack many short exposures. It’s trivial to throw out the outlier values which removes the satellite trails, and other sensor noise. Images with prominent streaks are being deliberately processed to only keep the bright outliers and delete the clean frames.
- sbierwagen 6y agoNote that Starlink satellites are visible due to reflected sunlight. You can only see them immediately after sunset.
- BurningFrog 6y agoSatellites are only lit by the sun for a while around sunset/sunrise. Once they're in Earth shade, they have no astronomy impact.
- hyperpape 6y agoWhat’s the connection between the brown dwarfs being cold and being exoplanets? Are planets definitionally not hot, or does it tell us something about how the dwarfs formed?
- T-hawk 6y agoThe definition of a brown dwarf is enough mass to cause nuclear fusion of deuterium (roughly 13x Jupiter's mass) but not enough for hydrogen-1 (roughly 75x Jupiter or 0.08x the Sun.) Planets by definition are anything that doesn't meet the deuterium threshold. Stars meet the hydrogen threshold. "Cold" in this context means relative to hydrogen-fusing stars. It's referring to the object's own energy production, not like measuring the surface temperature of a planet illuminated by a star. That we are finding "cold" brown dwarfs now is observational bias. We already found the hotter ones because they're more luminous and detectable. "Near the sun" (up to about 250 light-years here) is also observational bias, we just can't detect cold ones any farther.
- throwaway316943 6y agoI wonder what the ratio is of dark bodies to the star systems we can see? Are there vast numbers of invisible worlds hiding between the stars?
- zlynx 6y agoYes, as far as I know, astronomers think so. Those are exoplanets. Planets without any nearby stars. Even in our own solar system we don't know whats out in our Kuiper Belt. Probably nothing too big or we'd be able to measure the gravity effect. But in the Oort cloud, we could have multiple Pluto sized things out there and have no idea.
- kdmccormick 6y agoAn exoplanet is just any planet outisde our own star system. You're thinking of "rogue planets".
- ryanmarr 6y agoThis was misleading, they made it sound like they were inside our solar system.
- sadfev 6y agoAlmost a Clickbait
- cevn 6y agoCould we live on a brown dwarf?
- taf2 6y agoI imagine the gravity would be too strong?
- throwaway316943 6y agoPerhaps a floating colony like those proposed for Venus? There might be a Goldilocks zone in the atmosphere. If not then there may still be a comfortable location in near orbit where the heat would be tolerable. It’s interesting to think of ways to overcome an extreme gravity environment though, perhaps suspension in a liquid would counteract some of the effects?
- fhars 6y agoHow would you float something in a hydrogen atmosphere?
- rini17 6y agoHot hydrogen would.
- estebanisko 6y agoNot float, but you can keep aloft while spending minimal energy using https://en.wikipedia.org/wiki/Dynamic_soaring https://en.wikipedia.org/wiki/Dynamic_soaring Jupiter seems to have sufficiently dynamic atmosphere. Not sure about cold brown dwarfs...
- hinkley 6y ago> Some of these weird worlds are even relatively close to Earth's temperature and could be cool enough to have water clouds in their atmospheres, according to the statement.
- throwaway316943 6y agoI have seen the dark universe yawning Where the black planets roll without aim, Where they roll in their horror unheeded, Without knowledge, or lustre, or name.
- lostlogin 6y agoThanks. To save a few click for those like me - H. P. Lovecraft. https://www.hplovecraft.com/writings/texts/poetry/p121.aspx https://www.hplovecraft.com/writings/texts/poetry/p121.aspx
- mindcrime 6y ago"There are worlds out there where the sky is burning, where the sea's asleep and the rivers dream, people made of smoke and cities made of song. Somewhere there's danger, somewhere there's injustice and somewhere else the tea is getting cold. Come on, Ace, we've got work to do."
- wiml 6y agoSmoke me a kipper, Skipper, I'll be back in time for breakfast.
- 7373737373 6y agohttps://youtube.com/watch?v=lHgnrN8vhVs https://youtube.com/watch?v=lHgnrN8vhVs
- reillyse 6y agohttps://lithub.com/we-cant-ignore-h-p-lovecrafts-white-supremacy/ https://lithub.com/we-cant-ignore-h-p-lovecrafts-white-supre... http://www.cbsays.com/anti-irish-sentiments-h-p-lovecraft/ http://www.cbsays.com/anti-irish-sentiments-h-p-lovecraft/
- throwaway316943 6y agoYeah yeah yeah, everybody in the past was racist. They’re dead now so get the fuck over it. You can be a racist asshole and still make contributions to society and culture. Go back to Twitter.
- akerro 6y agoWhat does "cold brown" mean in this context? How can it be cold near the sun?
- perlgeek 6y agoThey are still several light years away from the sun, so "near" only on astronomical scales. "Brown dwarf" is an object bigger than a usual planet, but not big enough to spark and sustain nuclear fusion in the core. "cold" means "not hot enough to shine bright like a star".
- tazedsoul 6y agoMisleading headline.
- wkjagt 6y agoIf you look closely, you can often also spot a warm brown dwarf near Uranus.
- fernly 6y agoCredit where it's due, "Backyard Worlds" is one of a large number of "citizen science" projects hosted at Zooniverse[1]. The specific project is at [2], but the Zooniverse platform hosts many others affording pleasant hours of internet contribution. [1]https://www.zooniverse.org https://www.zooniverse.org [2] https://www.zooniverse.org/projects/marckuchner/backyard-worlds-planet-9 https://www.zooniverse.org/projects/marckuchner/backyard-wor...
- hinkley 6y agoAre any of them situated in a place that would be useful to us for getting to other places?
- sfifs 6y agoSo a question for the knowledgeable on this subject. Over the last few years, we continually keep seeing discoveries large number of intra and extra solar system astronomical bodies that do not radiate at high luminosities or frequencies. Presumably all these add to the mass of galaxies. How much of the dark matter hypothesis is dependent on observations of rotation of high luminosity bodies? If we assume there are large numbers of these non luminous bodies distributed between stars, does the necessity for postulating exotic dark matter go away?
- catmistake 6y agoDark matter is going away, regardless, because it is not necessary to explain galaxy rotation curves. https://www.youtube.com/watch?v=PL0ewiwqoTw https://www.youtube.com/watch?v=PL0ewiwqoTw Dark matter was always just a way to fudge what was observed. It is hard to believe most physicists, astronomers and cosmologists still believe in and are still looking for something that never existed.
- deleted 6y ago[deleted]
- dwaltrip 6y agoMy understanding is that MOND is essentially dead at this point and that there aren't any other promising alternative theories left on the table. I enjoyed a podcast on the topic by the highly respected physicist Sean Carroll (along with his guest, MIT physicist Lina Necib). It was very interesting and insightful. They cover in-depth why we are so confident that dark matter is a thing that exists. Here's a link to it: https://www.preposterousuniverse.com/podcast/2020/05/11/96-lina-necib-on-what-and-where-the-dark-matter-is/ https://www.preposterousuniverse.com/podcast/2020/05/11/96-l...
- catmistake 6y agoSimulation in video I linked is not MOND. Dark Matter is postulated due to observations of galaxies in isolation. BUT galaxies are not gravitationally isolated. They gravitationally affected by all the other galaxies in their neighborhood. The video and simulation is pretty straight forward. Dark Matter is simply unnecessary to explain galaxy rotation curves.
- LargoLasskhyfv 6y agoYay! Jump points! https://en.wikipedia.org/wiki/Jump_(Alliance%E2%80%93Union_universe) https://en.wikipedia.org/wiki/Jump_(Alliance%E2%80%93Union_u...
- cable2600 6y agoWhich one is the mythical "Nemesis" that throws comets and asteroids at Earth?