Hows does this sound for reasoning

[skywatcher]

Just had a thought:
7.8 LY away...too far, no worries, Right? WRONG!!!!!!!

If I, the human, first see Light that is 7.8 LY´s away. Then that Light happened millions of years ago. THIS DWARF WAS IN THAT POSITION THEY ARE SPEAKING ABOUT millions of years ago and has had, then, millions of years to get here!

And could therefore, be right outside our DOOR! And thus the SOHO pics of the 16th and yesterday (where they stopped the stream for 8 hours).

Okay, have at it: Where is my reasoning faulty?

[Christopher Ferro]

Um, no. By definition, the light took 7.8 years to reach us, thus that's where it was 7.8 year ago.

Nice try though. :-)

CJSF

[Boomgawa]

Okay, have at it: Where is my reasoning faulty?

Here goes:

If I, the human, first see Light that is 7.8 LY´s away. Then that Light happened millions of years ago.

Nope. If something is 7.8 LY away, then you're seeing light that was emitted/reflected from it only 7.8 years ago. No millions involved.

Matt

[TaeKwonDan]

Well for one, that there is absolutely no reason that a celestial body such as a Red Dwarf would have for orbiting our solar system. It's going to be the center of a solar system, not attracted to another one. Seems like a faulty understanding of orbital mechanics (and I'll be honest, mine aren't great).

Secondly, the object itself is still moving exceedingly slower than the light emitted by it so even if we start seeing signs that it's moving closer to us the object still isn't getting near for at least 10's of thousands of years.

[yubetcha]

Just had a thought:
7.8 LY away...too far, no worries, Right? WRONG!!!!!!!

If I, the human, first see Light that is 7.8 LY´s away. Then that Light happened millions of years ago. THIS DWARF WAS IN THAT POSITION THEY ARE SPEAKING ABOUT millions of years ago and has had, then, millions of years to get here!

And could therefore, be right outside our DOOR! And thus the SOHO pics of the 16th and yesterday (where they stopped the stream for 8 hours).

Okay, have at it: Where is my reasoning faulty?

Well, as I see it, if it was right outside our door, then we would STILL see it. Then the light would no longer be at 7.8 years, but minutes. Or maybe even seconds. Right? Hey, wait! What's tha...? (splat) :D :D

[LTC8K6]

Wouldn't it, unlike PX, look just a wee bit larger if it were right outside our door rather than light years away?

[skywatcher]

It was just a theory , so that means the object is actually itself 7.8 light years away or futher

[Peace_Rules]

Just had a thought:
7.8 LY away...too far, no worries, Right? WRONG!!!!!!!

If I, the human, first see Light that is 7.8 LY´s away. Then that Light happened millions of years ago. THIS DWARF WAS IN THAT POSITION THEY ARE SPEAKING ABOUT millions of years ago and has had, then, millions of years to get here!

And could therefore, be right outside our DOOR! And thus the SOHO pics of the 16th and yesterday (where they stopped the stream for 8 hours).

Okay, have at it: Where is my reasoning faulty?

To begin with, light travels at a constant, finite speed of 186,000 mi/sec. That is a speed. A light-year is a measure of distance, not time. It is the total distance that a beam of light, moving in a straight line, travels in one year. The answer to your question is rather simple, if you think about it. They didn't see the red dwarf from this postion, the saw the light produced from this dwarf, at that position.

A great example, the Sun is thought to be only 8 light minutes away from Earth, are you afraid of it? I don't get how you automatically assume this red dwarf is moving towards earth, there is no evidence of this.

[Grand Vizier]

Well for one, that there is absolutely no reason that a celestial body such as a Red Dwarf would have for orbiting our solar system. It's going to be the center of a solar system, not attracted to another one.

Not necessarily. The nearest star system to the Sun, Alpha Centauri, is triple, consisting of a close in pair of sun-like stars A and B. A long way out from these is a dim red dwarf, Proxima or Alpha Centauri C (which is in fact the closest known star to the sun). Most astronomers believe that Proxima is a bonafide member of the system on a long orbit though, in fairness, some feel it may just be passing through (it's very hard to establish a precise trajectory on an orbit that takes millions of years).

Anyway, my point is that there is no a priori objection to a system possessing an outlying red dwarf. Other examples are known. For weirdness, check out Castor, which is a 6-star system - two pairs of orange stars and an outlying doublet of red dwarfs orbiting the others.

[Boomgawa]

so that means the object is actually itself 7.8 light years away or futher

Well, if it's 7.8 LY away, we're seeing it as it was (and where it was) 7.8 years ago. I imagine it's moved in that time, mind you. And it's still emitting/reflecting light, so we can continue to observe it, but at a delay in years equal to its distance in LY (even if that distance increases or decreases).

Matt

[skywatcher]

and he agreed excpt this was his response
A Light Year IS indeed a measurement of Distance. But Light that takes 7.8 LY's would in fact mean something like 48 trillion miles away.

Now we know we can't count on this little baby to be near right? Well, not so fast. Remember what I said about the tunnels in space? They aren't exactly like tunnels on earth because they are made of 'energies'. The 'hyperphysical' laws governing them aren't exactly familiar to us.

If we presume that 'they' are telling us the truth about the distance (a huge leap of faith in and of itself), then we must ask: What is keeping this or Any Body out there stuck in our 3-d limited version of reality?

Indeed, nothing. All bets are off. Gonna sit back and watch the show. And learn as it progresses. But I will dare to state the obvious: Everybody was EXPECTING something to happen on the 20th. It wasn't supposed to show up before 'they' announced it. One can only conjecture what the Zeta role might be in all of this.
Could it be that they are planning to 'own' this process and unveil it at their discretion? Who is THEY? really.
It just gets better n' better...


What do you thin, it confused the heck out of me

[Grand Vizier]

and he agreed excpt this was his response
A Light Year IS indeed a measurement of Distance. But Light that takes 7.8 LY's would in fact mean something like 48 trillion miles away.

Now we know we can't count on this little baby to be near right? Well, not so fast. Remember what I said about the tunnels in space? They aren't exactly like tunnels on earth because they are made of 'energies'. The 'hyperphysical' laws governing them aren't exactly familiar to us.

[BIG SNIP]



Nope. Won't wash. That's just the old Star Trek way of getting out of a fix by inventing a new particle on a whim. Not only do we not have any proof that such 'tunnels in space' (you're probably referring to wormholes) exist, but if ordinary bodies in our universe took to racing down the nearest wormhole seemingly on a whim, there wouldn't be any physical structure to our Galaxy at all.

But why don't you go the whole way? If you've invoked wormholes, you no longer have to worry about close objects a mere 7.8 ly away. Any object in our Galaxy might take it into its head to drop by for a cup of tea at any moment. That's 400 billion stars for a start. Keep working on it - I think you have the basis of a loony cult of your own there.

[Fluffis the evil Hamster]

You're talking about Wormholes? (Einstein-Rosen tunnels, or whatever...)

These things are hypotheses. There's no real proof that they even exist, although, from what I've heard, they are mathematical possibilities.

[Boomgawa]

A Light Year IS indeed a measurement of Distance. But Light that takes 7.8 LY's would in fact mean something like 48 trillion miles away.

Yup. Something like that.

Remember what I said about the tunnels in space? They aren't exactly like tunnels on earth because they are made of 'energies'.

And the soundtrack grinds to a halt. Huh? I seem to have missed the Tunnels In Space discussion.

If we presume that 'they' are telling us the truth about the distance (a huge leap of faith in and of itself)

I'm guessing that by "they" you mean "astronomers". And yes, let's presume they're telling the truth, seeing as there's no reason for them to lie about it. Not exactly a huge leap of faith, especially when you compare it to the leap of faith required to believe in Tunnels In Space or aliens from Zeta Ridiculi.

What is keeping this or Any Body out there stuck in our 3-d limited version of reality?

Depends on how you consider theories involving more than three spatial dimensions. Three dimensions work pretty well for me, except when I stub my toe on a table. Pesky reality.

Matt

[TaeKwonDan]

Not necessarily. The nearest star system to the Sun, Alpha Centauri, is triple, consisting of a close in pair of sun-like stars A and B. A long way out from these is a dim red dwarf, Proxima or Alpha Centauri C (which is in fact the closest known star to the sun). Most astronomers believe that Proxima is a bonafide member of the system on a long orbit though, in fairness, some feel it may just be passing through (it's very hard to establish a precise trajectory on an orbit that takes millions of years).

Anyway, my point is that there is no a priori objection to a system possessing an outlying red dwarf. Other examples are known. For weirdness, check out Castor, which is a 6-star system - two pairs of orange stars and an outlying doublet of red dwarfs orbiting the others.

I stand corrected. A question though, if such an object was orbitting our solar system, even on a million year orbit, would we be able to observe signs of its presence currently or no?

[Flipper42]

Just had a thought:
7.8 LY away...too far, no worries, Right? WRONG!!!!!!!

If I, the human, first see Light that is 7.8 LY´s away. Then that Light happened millions of years ago. THIS DWARF WAS IN THAT POSITION THEY ARE SPEAKING ABOUT millions of years ago and has had, then, millions of years to get here!

7.8 light years away. Nothing to be afraid of. Proxima Centauri is 4.2 light years away and it is part of tri-star system rotating around a common center.

Flipper42
http://www.gotmoore.net

[Grand Vizier]

A question though, if such an object was orbitting our solar system, even on a million year orbit, would we be able to observe signs of its presence currently or no?

That's actually a good question, I think. Easy answer for a red dwarf - yes most definitely. I haven't got the magnitude calculations handy, but if the Sun had a Proxima then we would have picked it up long ago.

Another point is, are there any true stars (which will have to mean red dwarfs - anything brighter would stick out like a sore thumb) closer than Proxima? As far as I can make out, the general consenus is no, we'd have found them - but the 7.8 ly star was a bit of a surprise, so I suppose it isn't 100% impossible...

Brown dwarfs, though. That's up for grabs, because these radiate mostly in the infra-red and sky surveys are far from complete. I'm not sure what the detection radius would be - it would depend on the size of the BD for one thing. So, I don't think there is any a priori reason for there not being a brown dwarf in a hugely extended orbit - just that there is no special evidence for same.

Since some say that the Galaxy may contain quite an enormous population of singleton brown dwarfs, I can see it as quite likely that there may be one or more closer than Proxima, though.

If there's stuff there, one hope is that this spacecraft will spot some of it:

http://www.astro.ucla.edu/~wright/NGSS/

with follow-ups from the James Webb Space Telescope, which is optimised for infra-red.

[Grand Vizier]

This is cool too:

http://www.haydenplanetarium.org/hp/vo/du/wisesim.html

...collaborating with the WISE team. They cite that while there are 196 known stars within 25 light years of the Sun, they expect, statistically, to find 264 brown dwarfs within the same radius. I'd expect that to give real good odds of there being one closer than 4.2 light years...

[LTC8K6]

This guy never even needed Nancy!

[Grand Vizier]

This guy never even needed Nancy!

I do hope you don't mean me :(

(Edited: Ignore that - i checked back through the thread, and I see you don't. Wish you'd put a quote in though :) )

[LTC8K6]

You're joking, right?

[Grand Vizier]

You're joking, right?

Um. In what sense? Now I'm completely lost.

[LTC8K6]

I should have used a quote. My bad, GV!

[Grand Vizier]

I should have used a quote. My bad, GV!

:) It's OK guy - I got myself confused. Tracking this board, IRC, Yahoo groups and sci.astro (not much traffic on the last two at least). Curses - I was about to call it a thing on Zetatalk and move on to healthier concerns - and now she came up with her latest 'White Lie' from the Zetas. It's like a soap opera - I have to find out what comes next.