Astronomy and Planetary Science Thread

Astronomers had once calculated that billions of planets had gone rogue in the Milky Way. Now, scientists at NASA and Osaka University in Japan are upping the estimate to trillions. Detailed in two papers accepted for publication in The Astronomical Journal, the researchers have deduced that these planets are six times more abundant than worlds orbiting their own suns, and they identified the second Earth-size free floater ever detected.
With help from empirical models, the researchers worked out the spread of the masses for more than 3,500 microlensing events, which included stars, stellar remnants, brown dwarfs and planet candidates. (Data from one of those candidates was compelling enough for the team to claim the discovery of a new rogue Earth.) From this analysis, they estimate that there are about 20 times more free-floating worlds in our Milky Way than stars, with Earth-mass planets 180 times more common than rogue Jupiters.




 
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It is only a matter of time before we discover what the fifth force is, I have been following this ever since I was younger.
 
Score one for MOND here it seems over dark matter.

A new study reports conclusive evidence for the breakdown of standard gravity in the low acceleration limit from a verifiable analysis of the orbital motions of long-period, widely separated, binary stars, usually referred to as wide binaries in astronomy and astrophysics.

On the results, Chae says, "It seems impossible that a conspiracy or unknown systematic can cause these acceleration-dependent breakdown of the standard gravity in agreement with AQUAL. I have examined all possible systematics as described in the rather long paper. The results are genuine. I foresee that the results will be confirmed and refined with better and larger data in the future. I have also released all my codes for the sake of transparency and to serve any interested researchers."

A new revolution in physics seems now under way. Milgrom says, "Chae's finding is a result of a very involved analysis of cutting-edge data, which, as far as I can judge, he has performed very meticulously and carefully. But for such a far-reaching finding—and it is indeed very far reaching—we require confirmation by independent analyses, preferably with better future data."

"If this anomaly is confirmed as a breakdown of Newtonian dynamics, and especially if it indeed agrees with the most straightforward predictions of MOND, it will have enormous implications for astrophysics, cosmology, and for fundamental physics at large."


Here’s the related paper:

 
In recent research published by myself and my colleague Tony Yeates in the journal Tectonophysics, we investigate what we believe – based on many years of experience in asteroid impact research – is the world’s largest known impact structure, buried deep in the earth in southern New South Wales.

The Deniliquin structure, yet to be further tested by drilling, spans up to 520 kilometres in diameter. This exceeds the size of the near-300km-wide Vredefort impact structure in South Africa, which to date has been considered the world’s largest.

The impact that caused it may have occurred during what’s known as the Late Ordovician mass extinction event. Specifically, I think it may have triggered what’s called the Hirnantian glaciation stage, which lasted between 445.2 and 443.8 million years ago, and is also defined as the Ordovician-Silurian extinction event.

This huge glaciation and mass extinction event eliminated about 85% of the planet’s species. It was more than double the scale of the Chicxulub impact that killed off the dinosaurs.

It is also possible the Deniliquin structure is older than the Hirnantian event, and may be of an early Cambrian origin (about 514 million years ago).


Related paper:

 
That is a new find Flyaway. I am amazed at that it was more than double the scale of the Dino killer asteroid that struck the Earth 65 million years ago.
 
Sounds like somewhere the Silver Surfer might hang out.

A massive stellar behemoth is experiencing violent waves three times as tall as our sun crashing down on its surface. Known as a "heartbeat star," the extreme object also periodically pulses in brightness as the gravity of a close companion stretches it into an oblate shape.

The waves are absolutely huge, rising about 4 million kilometers (2.5 million miles) above the primary star's surface. They form when the companion star reaches what's known as periastron, which is the closest point in its 32.8-day orbit around the primary star. That primary star is also huge, with a gargantuan radius of 16.7 million kilometers (10.4 million miles) or 24 times the radius of our sun. The outer layers of this bloated star are diffuse and more weakly held by gravity, making it easier for the gravitational tides to distort them.


Related paper:

 
Astronomers using the James Webb Space Telescope (JWST) have confirmed that a distant smudge of light named for a lucky birthday girl on Earth is one of the earliest known galaxies in the universe.


Related paper:


And related video:

View: https://youtu.be/M1n82zTBwQY
 
Pushing the limits of the current 13.8 Billion year age of the known Universe Flyaway? I am one of those people that think the Universe is even older than that, 14-15 Billion years. I will not be surprised if the JWST discovers yet another galaxy even older than Maisie's galaxy.
 
You would not like to be anywhere near a Magnetar publiusr. Magnetars are strong enough to wipe all the data on a credit card instantly and and do things much worse. :eek:
 
A newly discovered star system is breaking records — and helping scientists unravel the mysteries of an extreme type of planet known as hot Jupiters. In a paper published Aug. 14 in the journal Nature Astronomy, researchers describe how the system could help further our understanding of worlds beyond our solar system.

The binary system, located 1,400 light-years away, consists of a "white dwarf" and a "brown dwarf."

This particular brown dwarf is unusual in that it is about the same size as Jupiter but has about 80 times Jupiter's mass. In other words, it's incredibly dense — and incredibly hot. The object is tidally locked, with one side permanently facing its companion star while the other side faces away. On the "day side," temperatures soar to more than 17,000 degrees Fahrenheit (9,500 degrees Celsius) — about 7,000 F (3,900 C) hotter than the surface of the sun. Its "night side" is cooler — about 4,900 F (2,700 C).


Related paper:

 
Podcast covering the latest research into the Antikythera Mechanism as a celestial calculator. I got caught by spoilers for the new Indiana Jones film, which I haven’t seen yet, so beware that.

 
Now, we have a new comet that could reach naked eye visibility over the next few weeks: C/2023 P1 Nishimura. The comet was discovered by Hideo Nishimura while shooting wide-field images from Kakegawa, Japan on the night of August 11th. At the time, the comet displayed respectable a 5’ coma. Score one for the human observers, versus robotic all-sky surveys…

 
So Astronomers are unsure as to how bright Comet P1 will get. Hmm, I don’t think that I will be holding my breath for this Comet, a lot was said about Comet ISON but it broke up
 
Researchers have identified a new speed limit for the universe’s most extreme collisions. According to a study published in the journal Physical Review Letters, the "maximum possible recoil velocity" for colliding black holes exceeds a whopping 63 million mph (102 million km/h) — about one-tenth the speed of light. This peak occurs when the collision conditions are at the tipping point between the two black holes either merging together or scattering apart as they approach each other, according to the study authors.


Related paper:

 
Seems Avi Loeb is making himself unpopular with his scientific peers through his wild claims. In fact they are now boycotting peer reviewing his work.


He seems to have caught the Didier Raoult illness... symptomas are an hyperinflated ego growing past the size of Jupiter... then brainworms then brain death.
 
Has JWST found supermassive Dark Matter Stars?

She sounds somewhat sceptical about this paper, though points out it would explain where Supermassive Black Holes come from. As they would be so massive these Dark Matter Stars that they would instantly collapse into Supermassive Black Holes:

View: https://youtu.be/hpYWK4x5rUA?si=vr1xc3-TtP1hd486
 
I would not like to say whether JWST has found Dark Matter stars or not yet Flyaway, they should do follow up observations with Euclid to see if that is the case before announcing their results, though it would be interesting to see if that it where the missing Dark Matter has been hiding all along.
 
I have a personal theory that on alternate full moons a paper is published arguing that earthlike planets orbiting red dwarfs can or cannot be habitable. This complicates things with unstable sporadic rotation:


Links:


 
New paper on a much smaller proposed planet nine than Mike Brown. This sounds more in line with Alan Stern’s proposals for another planet in the Kuiper Belt.

Is There an Earth-like Planet in the Distant Kuiper Belt?

Abstract
The orbits of trans-Neptunian objects (TNOs) can indicate the existence of an undiscovered planet in the outer solar system. Here we used N-body computer simulations to investigate the effects of a hypothetical Kuiper Belt planet (KBP) on the orbital structure of TNOs in the distant Kuiper Belt beyond ∼50 au. We used observations to constrain model results, including the well-characterized Outer Solar System Origins Survey (OSSOS). We determined that an Earth-like planet (m ∼ 1.5–3 M⊕) located on a distant (semimajor axis a ∼ 250–500 au, perihelion q ∼ 200 au) and inclined (i ∼ 30°) orbit can explain three fundamental properties of the distant Kuiper Belt: a prominent population of TNOs with orbits beyond Neptune's gravitational influence (i.e., detached objects with q > 40 au), a significant population of high-i objects (i > 45°), and the existence of some extreme objects with peculiar orbits (e.g., Sedna). Furthermore, the proposed KBP is compatible with the existence of identified gigayear-stable TNOs in the 2:1, 5:2, 3:1, 4:1, 5:1, and 6:1 Neptunian mean motion resonances. These stable populations are often neglected in other studies. We predict the existence of an Earth-like planet and several TNOs on peculiar orbits in the outer solar system, which can serve as observationally testable signatures of the putative planet's perturbations.

 
Astronomers report the discovery of a new massive and quiescent galaxy at a high redshift. The galaxy, which received designation COSMOS-1047519, was detected using the Keck I telescope. The finding was detailed in a paper published August 29 on the pre-print server arXiv.


Related paper:

 
That is news for me Flyaway, as long as the Solar System does not aproach the Hyades cluster in the next million years then there is nothing for us to worry about.
 
New paper on a much smaller proposed planet nine than Mike Brown. This sounds more in line with Alan Stern’s proposals for another planet in the Kuiper Belt.

Is There an Earth-like Planet in the Distant Kuiper Belt?



There are many different possibilities. It is a fascinating subject.

Best way of summarizing the debate and hypothesis: a) planet sizes b) distance in Astronomical Units and c) our telescopes present magnitude limit.

1-For a start, scientists have managed to calculate the amount of mass in both Kuiper Belt and Oort cloud.
Latest news: that mass cannot be more than half-a-Neptune or a smaller Uranus. They express it in "Earth mass".

So (drums rolling) Kuiper Belt + Oort Cloud: whatever is beyond Neptune cannot be more than ten Earth masses. There ain't another Jupiter or Saturn or Neptune out there, otherwise it would play havoc with all the Oort and Kuiper objects and we poor souls would be bombarded - even with Jupiter eating a number of agressors directed inwards the solar system. Just ask the dinosaurs opinion on the matter, even if TBH, what wiped out them wasn't interstellar.

Ten Earth masses is quite a large number. Could be Uranus, could be asteroids and comets, but the last two are peanuts. And between the two extremes: plenty of planet sizes.

Which size a planet there, and how many of them ?

-Full blown planets
a) 10-Earth mass
b) Earth mass
c) Mars mass
d) Mercury mass

-Dwarf planets
e) Pluto size
f) Ceres size

So there are (kind of) six possible size of planets.

Also: the smaller the size, the more hypothetical planets.

Back to that list

-Full blown planets
a) 10-Earth mass --------- could be only 1
b) Earth mass--------------could be 2 of them
c) Mars mass---------------could be 3-4 of them
d) Mercury mass-----------could be even more (no idea: around 10 ?)

-Dwarf planets
e) Pluto size---------------(many more, think of what happened in 2006 when Pluto was downvoted)
f) Ceres size---------------(many many many more - think of Ceres shamelessly leaving behind Asteroids - to Vesta, the new king)

Which means the solar system will probably, someday, explodes his planet count... provided we can find all those icy cold far away worlds !

And there comes the last parameter: magnitude.

Nowadays, our best of the best telescopes can reach magnitude 27. For the sake of comparison our naked eye is a pathetic 6 - and that's why we never saw Uranus and Neptune before Galilei and the age of optical astronomy.

So - magnitude 27. How does that translates for faraway planets ?

- we could see Uranus and Neptune smaller sister (the 10 X time Earth) up to 1000 AU.
- which means that the rocky ones must be closer than that: from memory, we won't see them past a few hundred AU.
- the smaller the planet, the harder to catch it. Presently we are finding Pluto rivals and sisters at less than 100 AU.
- Pluto is around 50 AU, Neptune and Uranus (from memory) at 30 - 40 AU.

So that's what we can see as of today.

But the solar system doesn't stop at 1000 AU. Not at all. The Centauri system is 4.5 lightyears away, and the Oort Cloud probably stretch to 1/3 rd of the way: 1.5 light year.

Now, how much AU is 1.5 lightyear ? 63240 AU is 1 lightyear, so 1.5 would be close to 100 000 AU. 94 000 something, TBH.

Wait, 100 000 AU to the fringe of the solar system ? but our telescopes magnitude 27 is presently blind beyond 1000 AU.

Which exactly means something: we cannot see planets beyond a miserable 1% of our solar system depths. One percent - and that's the absolute best case for the maximum-mass planet allowed by the Kuiper Belt / Oort Cloud mass calculations: a smaller Uranus or a half-Neptune.

If that fat planet is beyond 1000 AU, we are blind. And anything smaller up to Earth size is presently invisible beyond 500 AU - if we are lucky.

Now, just think about it. Within that 10 X Earth mass limit, and beyond 1000 AU - there might be Earths, there might be Mars, there might be Mercurys, and there might be a boatload of dwarf planets - Pluto and Ceres -size.

We have merely scratched the surface of the solar system.

And by the way - there are roughly 200 billion stars in our Milky Way - and a good fraction of them might have planetary systems. During the creation of all those systems, they ejected plenty rocky planets. So there might be 1000 or even 10 000 billion "orphan" planets, the size of Earth or smaller, orbiting no star but the galactic center.

It is just mind blowing. Our galaxy alone might be teeming with bazillions of planets. So many of them, E.T might just jump from one rogue planet to another, like true... Hitchickers of the galaxy. To you, Douglas Adams.
 
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So when your hear Media talking about the "ninth planet" or "planet X" keep in mind nowadays it could be three different things

- a smaller Uranus at 500 AU +

- a Earth - Mars - Mercury size at 200 AU+

- another Pluto / Ceres around 100 AU

All three hypothesis are not mutually exclusive : in fact there are kind of three different planet hunts at the same time !

For the record, Pluto was found at (around) 50 AU in 1929, and it was one hell of achievement by Clyde Tombaugh - since the next KBO wasn't found until 1992 !

In a sense, the hunt for the tenth... crap, the ninth planet is a saga started a few decades after Uranus discovery, when its calculated orbit did not matched with telescopic observations. This led to Neptune discovery... and the same problem repeating, so the hunt was on for a third one. This led to Pluto "false start" in 1929 until the problem was solved differently in 1992 - courtesy of Voyager 2 checking Uranus and Neptune masses. Surprise surprise: they were a touch smaller than estimation, and this anihilated the 150 year enigma.

Except the same year 1992, the "Pluto problem" bounced up - with the discovery of the first KBO. Then Pluto was downvoted in 2006, which Ceres ascending out of asteroid and crashing the party.

Yet the hunt of Planet ten - now planet nine, and still Planet X, bounced again. With telescopes fast improving, the 100 AU limit was busted, and so were magnitude improvements. This opened a brand new frontier between 100 and 1000 UA. And then, enter Mike Brown and all his smart fellows.
The quest for "new dwarf planets" (at 50 - 100 UA) was then flanked with two new searches: "something the size of Mercury to Earth" around 200 AU; and, wait, Oort and Kuiper mass would allow a mini-Uranus, 10 times max the mass of Earth - and we could see that up to 500 to 1000 AU.

So there not one, but three hunts
- "moar Pluto"
- "moar rocky planets"
- "one moar ice giant"

It's crazy.
 
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The theory I quite liked a while ago was rather than another planet the Sun may have a binary companion in orbit about it in the shape of a primordial black hole, a type of mini black hole that’s been theorised but never observed.
 
In 1217, a German monk looked to the starry southwest sky and noticed a normally faint star shining with unusual intensity. It continued to blaze for several days. Abbott Burchard, the leader of Ursberg Abbey at the time, recorded the sight in that year's chronicle. "A wonderful sign was seen," he wrote, adding that the mysterious object in the constellation Corona Borealis "shone with great light" for "many days."

This medieval manuscript may have been the first record of a rare space phenomenon called a recurrent nova — a dead star siphoning matter from a larger companion, triggering repeated flares of light at regular intervals. According to new research, the "wonderful" star in question may be T CrB, which sits in the constellation Corona Borealis and dramatically increases in brightness for about a week every 80 years. But it has been scientifically documented only twice — once in 1866, and again in 1946. (The star’s next long-awaited flare-up is expected in 2024).


Related paper:

 
The theory I quite liked a while ago was rather than another planet the Sun may have a binary companion in orbit about it in the shape of a primordial black hole, a type of mini black hole that’s been theorised but never observed.

Hell yes, Planet 9 as a PBH. I collected every single paper on the topic for my alternate space history. That thing has serious "The expanse" rings vibes. Imagine.
 
The theory I quite liked a while ago was rather than another planet the Sun may have a binary companion in orbit about it in the shape of a primordial black hole, a type of mini black hole that’s been theorised but never observed.

I like this form the 1978 Black Holes book edited by Jerry Pournelle.

Pluto was a puzzler, however. An object six times Earth's mass was expected to show a disk when observed using large telescopes, but Pluto did not. Furthermore, the planet had a bizarre tilted orbit that partly overlapped that of Neptune.

As astronomers continued their observations of Pluto, they revised estimates of its size downward. By 1960, some astronomers thought that it was about the size of Earth; others thought it might be as small as Mercury. This only increased the mystery surrounding the planet, for if it was to account for the observed discrepancies in Neptune's orbit, then it had to be several times as massive as Earth. Some astronomers proposed the existence of another, larger planet beyond Pluto. One scientist proposed a much more novel explanation.

George Peterson Field was the pen name of Dr. Robert Forward. Safely hidden behind the protective cloak of his nom de plume, the newly minted Ph.D. physicist speculated in a "science fact" article in the December 1962 issue of Galaxy science fiction magazine that Pluto was a gift from a "Galactic Federation."

He began by calculating that a body about the size of Mercury but with six times the mass of Earth would be so dense that it would have to be made of the collapsed matter found only in certain dwarf stars. Such an object could not exist naturally; unrestrained by the massive gravity of a dwarf star, it should have exploded long ago. Therefore, Forward asserted, Pluto must be artificial.

He suggested that Pluto was in fact a "gravity catapult." He wrote that "it would have to be whirling in space like a gigantic, fat smoke ring, constantly turning from inside out." A spacecraft that approached the ring's center moving in the direction of its spin would be dragged through "under terrific acceleration" and ejected from the other side.

If the acceleration the ultradense smoke ring gave the spacecraft were about 1000 times the acceleration Earth's gravity imparts to falling objects, then the ring would boost the spacecraft to nearly the speed of light in about one minute. The passengers and crew would, however, feel nothing as their spacecraft accelerated, for the gravitational force from the roiling ring would act on every atom of it uniformly. The ring would slow by a small amount as it accelerated the spacecraft.

Forward wrote that a "network of these devices in orbit around interesting stars" would provide "an advanced race" with an "energetically economical" means of star travel. The rings in the network would "cartwheel slowly" so that over time they would point at many possible destination stars.

A spacecraft accelerated by a ring could, upon arriving at another star in the network, enter that star's ring moving against the ring's spin. This would decelerate the spacecraft very rapidly and increase the ring's spin by a tiny amount. In effect, the spacecraft would pay back the network for the acceleration it borrowed when it began its journey.

Forward ended his article by noting that such a device could be shot through space by a larger gravity catapult and braked "by pushing against a massive planet," such as Neptune. This, he added, might account for Pluto's odd orbit with respect to the eighth planet. He speculated that, at some time in the past, the Galactic Federation had noted the rise of humans and had launched Pluto toward Sol to serve as "a coming out present."

Forward's concept is so imaginative and appealing that it ought to be true. New data on Pluto soon ruled it out, however. In 1977, James Christy of the U.S. Naval Observatory Western Station, located just a few kilometers from Lowell Observatory in Flagstaff, Arizona, found Pluto's moon Charon. The discovery of a body orbiting Pluto enabled astronomers to calculate its mass accurately for the first time. Pluto, as it turned out, has only one-quarter of 1% of Earth's mass. Subsequently, it was found to have a diameter of only about 2350 kilometers, making it only two-thirds as large as Earth's moon. After the turn of the 21st century, Pluto was found to have four more moons, all smaller than Charon.



Though Pluto did not turn out to be a link in a galactic transportation network, it did turn out to be a link to something big. Pluto was the first member of the Kuiper Belt to be found. The Kuiper Belt, a part of the Solar System long theorized but only confirmed beginning in 1992, is the "third realm" of bodies orbiting the Sun after the Sun-hugging realm of the rocky planets and the realm of the giant planets. It is far bigger than the first two realms combined. As New Horizons closes in on Pluto, we know of over 1000 bodies in trans-Neptunian space. Astronomers estimate that more than 100 times that number might exist. Assuming that New Horizons continues to operate as planned, mission planners expect to direct it past several more Kuiper Belt Objects after the Pluto flyby.

If Pluto is so small that it cannot account for the discrepancies in Neptune's orbit, then what does? In August 1989, the Voyager 2 spacecraft flew past Neptune. By carefully tracking the robot spacecraft, celestial dynamicists refined their estimate of Neptune's mass. When they did, the observed discrepancies in its orbital motion vanished. There was thus never a need to find a Planet X. Error had led to coincidence, and the result was mysterious Pluto.
 
Hell yes, Planet 9 as a PBH. I collected every single paper on the topic for my alternate space history. That thing has serious "The expanse" rings vibes. Imagine.
By a strange coincidence I’m currently going through a book called a Brief History of Black Holes and the chapter I’ve just reached is covering the theory I outlined above. It’s a good book by the way highly recommended.
 
I hope Planet 9 is a black hole.

Say you feed a line into it...such that it pulls the spacecraft towards it at great speed--- detach and do a fly-by?
 
A team of astronomers has, for the first time, "weighed" dark matter haloes surrounding actively feeding supermassive black holes in the bright hearts of ancient galaxies.

And according to a new study, scientists suggest dark matter haloes around such active galaxies could help funnel matter toward the central black hole, acting as a cosmic delivery service helping feed the titans. This new work indicates that such a feeding mechanism was indeed at work around hundreds of ancient quasars and suggests the process is one that's been constant throughout the history of the universe.


Related paper:

 

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