0.8AU or 0.8 Light Years?
0.8 AU in the sub-heading got my attention, but the text seems to suggest 0.8 light years, which is more comforting.
Back when Homo sapiens neanderthalensis strode or shambled or knuckled along the earth, about 70,000 years ago, the prehuman simians may have been able to see a small star passing through the fringes of our solar system. So say the authors of a new paper, The Closest Known Flyby of a Star to the Solar System, in The …
"When Homo sapiens neanderthalensis walked the earth, about 70,000 years ago, they may have been able to see a small star passing the fringes of our solar system"
in which case you'd better get the red pen out again alter the bit about fringes of the solar system too!
There's a big difference between 0.8 light years and the hours that it takes to get to the edges of the solar system
If the Oort Cloud is real, then yes.
But let's keep in mind no one has ever seen the Oort Cloud. It was a suggestion. not a discovery. It was a convenient explanation for the origin of comets. And surely this passing star stirred up a great many comets and sent them crashing about our ears.
What's that? It didn't? Hmmmm...
"Can somebody explain to me how two planets can separate 20 light years in 70,000 years please."
As noted elsewhere in these comments, that requires 1/3500th light-speed, which sounds impressive because it has "light speed in it." At a quick conversion, that's 86 kilometers per second.
While a bit speedy compared to human space probes, and above the average speed of stars around the sun (~20km/s, because Sol is moving faster than the local group average), it's hardly setting a record. A number of stars, some even with spiffy Hubble photographs, get above 100km/s relative to neighbors and galactic halo stars crossing the plane of the galaxy can do so at 245km/s.
Take a moment to skim this for some of the exceptional speedsters. Scholz doesn't even really rate among them:
http://en.wikipedia.org/wiki/Stellar_kinematics
"I notice El Reg has remembered the comments from the other day about a red star shining white light on a planet"
I don't know to which comment this is referring, so forgive me if I am preaching to the converted, but this is a common misconception. There is no such thing as a red star. Even the coolest stars have a colour temperature of nearly 3000K or so. This is still whiter than a halogen light bulb, and so while most of its output is in the infra red it would still illuminate any nearby planets with a whitish light.
"> any objects the star disturbed are not going to make themselves known for many millennia
So where are they????"
To clarify the article a bit, its usage of "many" is approximately equal to "2000." In other words, the Oort cloud comets disturbed by Scholtz's Star are about 2 million years away from the inner Solar system.
http://en.wikipedia.org/wiki/Scholz's_Star
And given the rotational and orbital motion of Earth with respect to the Oort cloud, there will be times in the year when - as another poster said - they're behind you.
Hate to pour cold water over the nice idea that Neanderthals would have been startled by flares of Scholz's Star., but a little back of the envelope calculations shows this is unlikely:
The star would have been about magnitude 10.3 in the night sky at shortest distance to earth, apparently. This means that to be visible a flare would need to raise the brightness by 4.3 magnitudes to reach magnitude 6 (drop on the magnitude scale = increase in brightness). This is possible in the blue band, but in the visual band (roughly corresponding to the rods in the retina) it is more likely to observe just one or two magnitudes increase, keeping the star well hidden. Only a 6 or 7 magnitude increase would make the star noticable (but still rather mediocre), and something like 12 magnitudes would be needed to rival the planets. This is VERY unlikely
Still a very interesting report
I think you'll find that a chap called Herbert Wells can claim prior art on that, with his 1897 story _The Star_:
https://ebooks.adelaide.edu.au/w/wells/hg/star/
Thanks for prompting me to reread it. (It's quite short, only about 4500 words.) Even 118 years later it's got surprising power, and it's scientifically not bad either, even by today's standards.
(I was going to add that the body in question is too small to be a real star, but a closer reading of the story shows that Wells knows this quite well --- before the collision with Neptune it's not luminous. A dark gas giant from the Oort cloud, maybe? Of course, what Wells *doesn't* say is that whatever it is is probably now on a highly elliptic orbit taking it into the inner solar system, and another Earth interception is likely, although not for a while. At least it's going to threaten the Martians as well. Serves them right, the smug gits.)
Perhaps from this song?
Michael Rennie was ill
The Day the Earth Stood Still
But he told us where we stand
And Flash Gordon was there
In silver underwear
Claude Rains was The Invisible Man
Then something went wrong
For Fay Wray and King Kong
They got caught in a celluloid jam
Then at a deadly pace
It Came From Outer Space
And this is how the message ran...
Science fiction (ooh ooh ooh) double feature
Doctor X (ooh ooh ooh) will build a creature
See androids fighting (ooh ooh ooh) Brad and Janet
Anne Francis stars in (ooh ooh ooh) Forbidden Planet
Wo oh oh oh oh oh
At the late night, double feature, picture show
I knew Leo G. Carroll
Was over a barrel
When Tarantula took to the hills
And I really got hot
When I saw Janette Scott
Fight a Triffid that spits poison and kills
Dana Andrews said prunes
Gave him the runes
And passing them used lots of skills
But When Worlds Collide
Said George Pal to his bride
I'm gonna give you some terrible thrills
Like a...
Science fiction (ooh ooh ooh) double feature
Doctor X (ooh ooh ooh) will build a creature
See androids fighting (ooh ooh ooh) Brad and Janet
Anne Francis stars in (ooh ooh ooh) Forbidden Planet
Wo oh oh oh oh oh
At the late night, double feature, picture show
I wanna go - Oh oh oh oh
To the late night, double feature, picture show
By R.K.O. - Wo oh oh oh
To the late night, double feature, picture show
In the back row - Oh oh oh oh
To the late night, double feature, picture show
Or what The BBC think are scientists- like the land whale on (in name only now) Sky at Night. or the guy the get in for the Horizon-light programs that isn't "super(s)tar(d)* Prof." Cox (Dallas something or other ?)
(praying to any deity for some decent science programs on the BBC)
*s or d depending on who you ask.
He's appeared here before: Boffin the boffin and his boffinry pals in double dwarf super-prang alert.
Clearly we have not, as its sub-title asked, reached Peak Boffin yet.
I recall the Toba catastrophe was also ABOUT 70,000 years ago, mass volcanic eruptions on Earth, dwindled human population down to a speculation 1,000 to 15,000 mating pairs total. Toba put Earth into a 1,000 year cool down phase.
I can only wonder if the gravitational pull from these two binary stars might have been responsible.
As to the second star that passed through, I read that near-infrared spectroscopy reveals subtle peculiarities indicating the presence of a T5 binary companion, and high-resolution laser guide star adaptive optics imaging reveals a faint (ΔH = 4.1) candidate source 0"14 (0.8 AU) from the primary.
So the two binary stars here are about 0.8 AU away from each other. We don't know how fast one circles the other.
I intuit that two stars passing through our solar system? at the same time ? near mass extinction on Earth due to to date- unknown causes for the volcanic eruptions ? have to be connected.
If you do the math here too, says they are now 20 light years away, and were here 70,000 years ago, this works out to be about 1/3500th the speed of light as a velocity. Remembering velocity is as mass - that extreme velocity there + the mass of the stars themselves probably caused serious havoc as to gravitation influence in our solar system.
I'm just amazed to think about this, what it must have looked like.
REAL neat story.
Tim Miltz
They can't have caused gravitational havoc in the Solar System for the simple reason that the Solar System remains stable. The models used by the authors predict that it had minimal effects on the Oort Cloud which is much closer and much more weakly bound to the Sun than the Earth, so there would have been an utterly neglible effect here on Earth.
Toba erupted because that's what calderas do. It's big, but it's not even in the top ten caldera events known in the geological record let alone the numerous flood basalts out there which make Toba look like a firecracker.
"If you do the math here too, says they are now 20 light years away, and were here 70,000 years ago, this works out to be about 1/3500th the speed of light as a velocity."
Yep. Neat and quick calculation.
"Remembering velocity is as mass - that extreme velocity there + the mass of the stars themselves probably caused serious havoc as to gravitation influence in our solar system."
Relativistic mass increases only happen at a large percentage of light speed, not 1/3500th light speed. The mass multiplier M equals the original mass divided by the square root of (1 - v^2 / c^2), where c = light speed and v = the velocity of the mass in question.
At 1/3500th light speed (0.000286c), the mass increase of the system is thus:
M = Mo / sqrt [1 - (0.000286c)^2 / c^2 ]
M = Mo / sqrt [1 - 0.000000082]
M = Mo, if you ignore anything after the 7th decimal place
So the questions become, "What are those rest masses and what are they going to do at 0.8 light-years (51,200AU) from the Solar system?"
Answer 1: Well, Scholz's Star is 0.15x Sol's mass and its companion is lighter, a brown dwarf estimated to be 65 Jovian masses (0.065x Sol's mass). The pair orbit each other at 0.8AU, which - on the scale of the 51,200AU separation - is small enough that you can approximate them as a single mass of 0.215 Solar mass.
Answer 2: Let's look at a sampling of planets at extremes of the solar system:
1) Earth. Earth is 1AU from Sol and, basically, 51,200AU from Scholz & Co. Defining Sol's influence as 1, the inverse square relationship of gravitational force indicates Scholz & Co. will have 0.215 / (51200^2) = 8.2x10^-11 times the influence of Sol on Earth. Schultz's tidal effects, which follow an inverse cube relationship, will be 1.6x10^-15 times that of Sol. Jupiter's average tidal influence on Earth would be 5 billion times stronger than Scholz's. For that matter, a 747 full of American tourists flying over an ocean will probably generate larger tidal effects than Scholz.
2) Pluto. (It's a planet, even if saddled with a derogatory 'little object' adjective.) Pluto is about 40AU from Sol versus 51200 AU from Scholz & Pal. Sol will exert 7,620,465 times the gravitational force on Pluto as Scholz and 10 billion times the tidal effects.
I think it's fair to conclude Scholz didn't do much to the inner system - yet. In 2 million years we'll find out how dense the Oort cloud is and whether we're facing a made-for-SyFy disaster, Cometageddon.
"For that matter, a 747 full of American tourists flying over an ocean will probably generate larger tidal effects than Scholz."
If it's AMERICAN tourists you might want to bump up the mass and tidal affects up bit in your calculation...
I couldn't find it in Space Engine, but I did find this picturesque red dwarf binary near where it should be:
http://i.imgur.com/NQGxrg3.jpg
(The planet and its moon are orbiting the bigger star on the left; the smaller star is on the right. There's also a bunch of planets orbiting the pair way further out which are too dark to take good pictures of.)
It is, alas, wholly imaginary, and is procedurally generated.
What if..
The grey aliens from Nibiru noticed the Neandertals on their close flyby, realizing the potential of a hominid species with reasonable intelligence "borrowed" an isolated population therefore causing the Neandertal's extinction and indirectly causing H.sapiens to be the only surviving species.
Its just possible that the Wow! signal could have been deflected by a remnant black hole from this system to ours, assuming that the relocated Neandertals continued to evolve they would have reached a techological level comparable to ours around 1929 Earth time.
The time delay from their system to ours would be about right and it wouldn't need to have been a continuous signal just a "Hi there!" to see if they got a response.
They might not even have intended to send it as it could have been directed to another nearby system ie Gliese 581 or Alpha Orionis.
Not to be picky, but Neanderthals were not a "prehumen" species, rather a separate species of hominid that died out, and that likely interbred with contemporary homo sapiens before doing so. Not sure if the science is conclusive on the interbreeding, but think it's as good as. A Neanderthal human could be born into the modern world and live quite happily. Doubt he'd get many dates, though.
"...Homo sapiens neanderthalensis strode or shambled or knuckled..." "...the prehuman simians..."
Neanderthals were human beings, not "simians"! They did not "shamble" or "knuckle". They walked as fully upright as we do and their brains were larger than ours.
I hope that the author was trying to be cute but the ignorance of these statements is shocking.
Yeah, this racial stereotyping and discrimination of Neanderthals is shocking and unacceptable.
So much so, that I've decided to set up a Respect the Memory of the Neanderthal Benevolent Fund and will tell everyone where to send the donations shortly. It will be operated with full transparency and all donations will be used solely to remind me to respect the memory of the Neanderthals.
Bronson's Star.. When Worlds Collide
Also points out, even if a Stellar invasion were immenent, we probably wouldn't see it until almost too late.
The Radial velocity would be large, the tangential barely perceptable.
Since most detection instruments pay attention to the latter not the former, we would have very little advance notice.