This is the "time travel" aspect of astronomy that I find extremely fascinating.
I was just talking to my young sons the other day as we were watching the sunset that we are seeing something that happened 8 minutes ago. Cool to see them trying to get their young brains around this concept...
The sunset you were seeing didn't happen 8 minutes ago. Sunsets are an interaction of the sun with your perspective position on earth and line of sight. The sunset was happening right then -- the light that was involved in the sunset had been emitted from the sun 8 minutes ago. The last blip of the light you saw disappear over the horizon was a view of a corner of the sun from 8 minutes ago, but the sunset was happening essentially at that moment. </pedantic>
Approximately 1800 light years away, therefore he is right, if it collided in our year 222AD (well within existence of humanity), then it would appear in our skies in 2022 (ish).
Since speed of light is the defaco speed of everything and hence reality itself, it's for all intents and purposes yet to happen even if technically it's already happened. That's kinda how relativity works, if it hasn't happened for us, it hasn't really happened.
As Halley's comet was regarded as an omen for the defeat of the Saxon king Harald and the 1006 bright supernova in Scorpio was regarded as a bad omen and was accompanied with wars and famine in both Europe and Arabia and the 1997 Hale-Bopp comet resulted in the Heaven's Gate suicides, I wonder how astrologers or all kinds of semi-religious groups would regards this upcoming spectacle. Tycho Brahe predicted succesfully that the 1572 supernova would herald the decline of the Roman Catholic Church.
What will happen in 2022, a New World Order... or another day of the Triffids?
Good point. I think that depends entirely on how batshit crazy the human response is. Hopefully very little, but 5 years is plenty of time for people to come up with some self fulfilling prophecies / build a cult.
Fascinating. It will be wondrous to see if it occurs.
It also reminds me of a premise in one of my favorite science fiction novels, Diaspora by Greg Egan. In the story, the characters are monitoring the orbit of a binary star system. The orbit is decaying and a collision is expected at some point. However, soon the characters realize that the orbit is decaying far faster than expected. Extrapolating, and discovering new properties of stellar physics, the characters realize that the stars are mysteriously losing angular momentum, which will lead to them spiraling downward into a prompt collision that will produce supernova-scale energies. The binary star is in Earth's neighborhood, so this will put all life on the planet at risk. It will be brighter than the sun in daylight.
There's a great deal more to the plot than that (I don't want to spoil it) -- that's just the event that kicks things off. It's a great book and I'd highly encourage all sci-fi fans to read it. Hopefully nothing like this happens in real life, and we are confident and correct about the amount of energy that will be released :-)
While thinking about these topics, it is difficult not to ponder the frailty of life, and the astonishing vastness and expanse of the cosmos. How easy it would be for a star to snuff out all life on a world.
Seconded --- it's a great book. Egan has an amazing talent for off-handedly mentioning and then casting aside multiple mind-expanding ideas per chapter that other authors would expand into a complete novel.
Non-spoiler: I believe this book features the biggest sculpture in fiction.
It's been awhile since I've read it; I'm going to try and ask this question in a spoiler-free way: are you talking about the thing they end up 'chasing' through the 4-6-4-6 (or arguably 3-5-3-5, etc)?
Wikipedia says KIC 9832227 is "almost 1800 light years away" while SN 1987a is "167885 ly" from us. There should be an inverse square relationship for the intensity of light reaching us by our distance from the object, so light from this nova should be
You have: (167885 ly / 1800 ly)^2
You want:
Definition: 8699.1893
times brighter than that from SN 1987a due to proximity (which would still be much dimmer than the full Moon). However, the expected nova is also far dimmer to begin with:
There are tons of good advice threads on the internet for this, because it's actually a really hard decision.
I looked into it a year ago or so, and pretty much universally, the advice was, "start with really good binoculars, because even relatively expensive beginner telescopes aren't all that much better, and it's more important to understand what you're looking at than to see it well".
Then, by the time you know whether or not you're going to be "into it", you'll know if you want to spend a few grand on a Dobsonian (which isn't necessarily the best answer, but is a good example).
A bit of meta discussion that usually isn't mentioned in those advice threads:
There's a big divide between visual telescopes that you can use to see things 'live' with your naked eye, and observing telescopes that are mainly used for photography.
The visual ones are more fun, used e.g. for the Messier rally where you try to spot all Messier objects in one night. Let's say it'll be a 12" f/4 to f/10 mirror, giving you suboptimal magnification but nice and bright images. Easy handholdability, difficult to attach a camera, imprecise tracking if any at all. Telescope usually fits in your trunk and is made to be assembled each night.
The telescopes that are used for photography are more akin to classical observatories. Guiding motors are now mandatory, usually you'll have a stationary place (concrete foundation and all) to have your scope perfectly aligned. You'll use it almost exclusively computer-operated, timing the images across different color channels and working only remotely. This way it is actually possible to do research even as an amateur ... but also to capture deep sky objects like nebulae in their full color detail.
There are hybrids, but those are quite niche, and usually not best bang-for-buck. Personally I'm considering to get myself a tele lens or two, and a cheap outdated digital camera body along with it. That way I'll only need a tracking mount, and I'll have enough to dip my feet into the water.
Make friends with a friendly local astronomy club. It'll be free, you'll meet nice people, you'll get to use their glass, and you'll get as much advice as you want.
Or, as MPSimmons suggests, get some wonderful binoculars (in a pinch, the ones with the largest objective lenses you can find), a comfortable clear moonless night, and a blanket to lay on.
I'm not sure how to do the calculations on distance between the two, but I'd estimate this binary is well under 1,000 light years from Tabby's star given the constellation, RA, declination and distance are all close.
Edit: Added a zero as I'm not sure of the error margines on distance measurements.
Is that a regular event they listen for? I thought it was black holes colliding and a couple of average size stars wouldn't be significant enough to cause a blip.
It would be awesome if they could tie a gravity wave event with an event visible to the naked eye.
They don't listen for specific events, they wouldn't know when they were going to happen. They wait for any detectable gravity wave to occur. I just don't know what the magnitude and distance of such an event would show up.
Would the increased proximity of these two stars make up for this? I'm under the impression that the gravity wave detections so far have been colliding black holes billions of light years away - if these two are less than two thousand, might they be detectable (with current tech)?
Reminds of WR 104 [1] binary star system. When the two stars collide in the next 100 years there is a chance earth could be in the path of its gamma-ray bursts that can potentially end life on earth. The cool thing about it is that we won't know when it happens (already has happened because of limit of speed of light) until the gamma rays have reached earth which means there will be just a flash of light and then it's all over and it could happen anytime. Talk about existential thread to life. However, there isn't a very high likelihood of it happening though.
There is so much going on today that makes me fearful for the existential future of humanity: climate change, nuclear weapons, resource depletion, artificial intelligence, to name a few.
But strangely enough, a ticking cosmic countdown makes me feel oddly at peace with an ultimate future of extinction. I can only hope that the end of humanity will not be wrought by its own hands.
Makes me want to enjoy my time alive more, with the people I care about.
A lot of species threaten their existence by their own self-interest. Lemmings regularly lurch from near extinction to explosive overpopulation every few years.
A GRB hitting earth wouldn't actually cause an immediate extinction event. From Wikipedia:
> Earth's atmosphere is very effective at absorbing high energy electromagnetic radiation such as x-rays and gamma rays, so these types of radiation would not reach any dangerous levels at the surface during the burst event itself. The immediate effect on life on Earth from a GRB within a few parsecs would only be a short increase in ultraviolet radiation at ground level, lasting from less than a second to tens of seconds. This ultraviolet radiation could potentially reach dangerous levels depending on the exact nature and distance of the burst, but it seems unlikely to be able to cause a global catastrophe for life on Earth.
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[ 2.5 ms ] story [ 83.5 ms ] threadI was just talking to my young sons the other day as we were watching the sunset that we are seeing something that happened 8 minutes ago. Cool to see them trying to get their young brains around this concept...
This is false, and so is the rest of that reasoning.
The collision did already happen, from our frame of reference. Its light arriving to us will be just a confirmation.
From some other frame of reference (one moving very fast in the line that joins Earth and the collision), it might not have happened yet.
http://www.astro.com/astrology/aa_article141030_e.htm
https://en.wikipedia.org/wiki/Stars_in_astrology
With that extrapolation, I can't imagine this will be the catalyst for much.
It also reminds me of a premise in one of my favorite science fiction novels, Diaspora by Greg Egan. In the story, the characters are monitoring the orbit of a binary star system. The orbit is decaying and a collision is expected at some point. However, soon the characters realize that the orbit is decaying far faster than expected. Extrapolating, and discovering new properties of stellar physics, the characters realize that the stars are mysteriously losing angular momentum, which will lead to them spiraling downward into a prompt collision that will produce supernova-scale energies. The binary star is in Earth's neighborhood, so this will put all life on the planet at risk. It will be brighter than the sun in daylight.
There's a great deal more to the plot than that (I don't want to spoil it) -- that's just the event that kicks things off. It's a great book and I'd highly encourage all sci-fi fans to read it. Hopefully nothing like this happens in real life, and we are confident and correct about the amount of energy that will be released :-)
While thinking about these topics, it is difficult not to ponder the frailty of life, and the astonishing vastness and expanse of the cosmos. How easy it would be for a star to snuff out all life on a world.
Non-spoiler: I believe this book features the biggest sculpture in fiction.
(Currently reading _Incandescence_.)
https://en.wikipedia.org/wiki/SN_1987A
"Its brightness peaked in May with an apparent magnitude of about 3"
(a few million times fainter than the full Moon)
Wikipedia says KIC 9832227 is "almost 1800 light years away" while SN 1987a is "167885 ly" from us. There should be an inverse square relationship for the intensity of light reaching us by our distance from the object, so light from this nova should be
times brighter than that from SN 1987a due to proximity (which would still be much dimmer than the full Moon). However, the expected nova is also far dimmer to begin with:https://en.wikipedia.org/wiki/Luminous_red_nova#Characterist...
"The luminosity of the explosion occurring in luminous red novae is between that of a supernova (which is brighter) and a nova (dimmer)."
So I'm still going to say "safe to observe with a telescope".
I looked into it a year ago or so, and pretty much universally, the advice was, "start with really good binoculars, because even relatively expensive beginner telescopes aren't all that much better, and it's more important to understand what you're looking at than to see it well".
Then, by the time you know whether or not you're going to be "into it", you'll know if you want to spend a few grand on a Dobsonian (which isn't necessarily the best answer, but is a good example).
There's a big divide between visual telescopes that you can use to see things 'live' with your naked eye, and observing telescopes that are mainly used for photography.
The visual ones are more fun, used e.g. for the Messier rally where you try to spot all Messier objects in one night. Let's say it'll be a 12" f/4 to f/10 mirror, giving you suboptimal magnification but nice and bright images. Easy handholdability, difficult to attach a camera, imprecise tracking if any at all. Telescope usually fits in your trunk and is made to be assembled each night.
The telescopes that are used for photography are more akin to classical observatories. Guiding motors are now mandatory, usually you'll have a stationary place (concrete foundation and all) to have your scope perfectly aligned. You'll use it almost exclusively computer-operated, timing the images across different color channels and working only remotely. This way it is actually possible to do research even as an amateur ... but also to capture deep sky objects like nebulae in their full color detail.
There are hybrids, but those are quite niche, and usually not best bang-for-buck. Personally I'm considering to get myself a tele lens or two, and a cheap outdated digital camera body along with it. That way I'll only need a tracking mount, and I'll have enough to dip my feet into the water.
http://www.sfsidewalkastronomers.org/index.php?page=telescop...
Or, as MPSimmons suggests, get some wonderful binoculars (in a pinch, the ones with the largest objective lenses you can find), a comfortable clear moonless night, and a blanket to lay on.
Mostly, though, just go look.
(Linked to from here: http://www.ibtimes.co.uk/two-stars-are-about-smash-into-each...)
The star system in question is KIC 9832227, about 1800 light years away from us: https://en.wikipedia.org/wiki/KIC_9832227
Here's Tabby's star: https://en.wikipedia.org/wiki/KIC_8462852
I'm not sure how to do the calculations on distance between the two, but I'd estimate this binary is well under 1,000 light years from Tabby's star given the constellation, RA, declination and distance are all close.
Edit: Added a zero as I'm not sure of the error margines on distance measurements.
It would be awesome if they could tie a gravity wave event with an event visible to the naked eye.
[1] https://en.wikipedia.org/wiki/WR_104
Its also kinda of sad, but for a second I felt kinda happy reading this, knowing at least I wouldnt be in student debt
But strangely enough, a ticking cosmic countdown makes me feel oddly at peace with an ultimate future of extinction. I can only hope that the end of humanity will not be wrought by its own hands.
Makes me want to enjoy my time alive more, with the people I care about.
> Earth's atmosphere is very effective at absorbing high energy electromagnetic radiation such as x-rays and gamma rays, so these types of radiation would not reach any dangerous levels at the surface during the burst event itself. The immediate effect on life on Earth from a GRB within a few parsecs would only be a short increase in ultraviolet radiation at ground level, lasting from less than a second to tens of seconds. This ultraviolet radiation could potentially reach dangerous levels depending on the exact nature and distance of the burst, but it seems unlikely to be able to cause a global catastrophe for life on Earth.
https://en.m.wikipedia.org/wiki/Gamma-ray_burst
The long-term effects are what could kill us, namely, the destruction of the ozone layer.