how far is it from the earth in years how long ould it take to reach the earth if it was headed in our direction

The only brown dwarf discovery I'm aware of is the one recently discovered by the Chandra X-Ray Observatory in April. It is about 180 light-years from Earth, so it would take a long, long, long time to get here if it was coming this way, which it isn't

What brown dwarf? The only thing I read about was a newly discovered red dwarf that is about 7.8 light years away. It's not coming at us, relax.

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Luck? In my experience there is no such thing as 'luck.'

but I am trying to undertand how Light Years work,

how long would something 7.8 light years take to get to earth

7.8 years if travelling at the speed of light?

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The following tale of alien encounter is true and by true, I mean false. Its all lies. But they're entertaining lies, and in the end isn't that the real truth? The answer is no. - Leonard Nimoy, The Simpsons (maybe regarding Planet X?) :D

n/t

Where do they get them?

A light year is a measure of distance, not speed. It is the distance that light should traverse in one Earth year in a vacuum, or 5,865,696,000,000 miles.

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Luck? In my experience there is no such thing as 'luck.'

so it would take 7 years to reach here

No, it takes 7 years for the light it emits to get here. The object itself is not traveling at the speed of light.

I need help

Uh, ok, look, light travels at the speed of light, right? So if the red dwarf is 7.8 light years away, the light that bounces off of it or that it generates will hit earth in 7.8 years. However, if that red dwarf were coming right at us, which it is not, it would take (the distance from earth) divided by (the speed of approach) years to hit us.

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Luck? In my experience there is no such thing as 'luck.'

lol

How far is it actually from the earth aprroximatly

And that's what we're here for. Let's say that the outer spiral arm of the Milky Way (the galaxy our solar system is located in) moves at roughly 1 million miles a day (heard this somewhere so it might not be totally accurate, but I'm sure it's a good estimate.)

So 1,000,000 miles/day is actually equal to roughly 41,666 MPH. Pretty fast right? Well light moves at around 4 times that distance per second! So if our theoretical brown dwarf is 14 light years away and heading right for us it will be here in 5,865,696 days or roughly 16,000 years. I'm not going to buy my bomb shelter just yet. :wink:

No material object can travel at the speed of light, which is 186,000 miles per second in vacuum - all matter travels slower than light. For most objects, such as stars and planets, much, much slower. (Only some elementary particles approach light speed)

If that star were 7 light years away and moving straight at us at the speed of light, it would take 7 years to get here. If 10 light years away - it would take 10 years. This is how a light year is defined as a measuire of distance.

But - a more reasonable velocity for another star outside the Solar System might be, say, 10 miles per second relative to us. That is 1/18,600 of the speed of light. For the star 10 light years away, this means it would take 18,600 x 10 - i.e. 186,000 years to get here.

Hope this helps. Otherwise - what concept are you having problems with?

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Fin
Skep-ti-cult® member #488-28303-790

I believe I mistakenly did my time and distance calculation for 1 light year. So you would need to multiply that by a factor of 7 or 14 (depending on which distance you want to use). So 112,000 years or 224,000 years until it gets here.

but you said if it were 7 light years away then it would take 7 years the same with 10 years but below mentioned a greater date, which is it

If it was 7 light years away, traveling the speed of light, it would be here in 7 years. But its not, because it can't, so it will take longer.

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7 light years away

Original NASA press release on the red dwarft

PRESS RELEASE
Date Released: Tuesday, May 20, 2003
Jet Propulsion Laboratory

Newly-Discovered Star may be Third-Closest
Jane Platt (818) 354-0880
Jet Propulsion Laboratory, Pasadena, Calif.

William Steigerwald (301) 286-5017
Goddard Space Flight Center, Greenbelt, Md.

The local celestial neighborhood just got more crowded with a discovery of a star that may be the third closest to the Sun. The star, "SO25300.5+165258," is a faint red dwarf star estimated to be about 7.8 light-years from Earth in the direction of the constellation Aries.

"Our new stellar neighbor is a pleasant surprise, since we weren´t looking for it," said Dr. Bonnard Teegarden, an astrophysicist at NASA´s Goddard Space Flight Center, Greenbelt, Md. Teegarden is lead author of a paper announcing the discovery to be published by the Astrophysical Journal. This work has been done in close collaboration with Dr. Steven Pravdo of NASA´s Jet Propulsion Laboratory, Pasadena, Calif.

If its estimate of distance is confirmed, the newfound star will be the Sun´s third-closest stellar neighbor, slightly farther than the Alpha Centauri system, actually a group of three stars a bit more than four light-years away, and Barnard´s star, about six light-years away. One light-year is almost six trillion miles, or nearly 9.5 trillion kilometers.

The new star has only about seven percent of the mass of the Sun, and it is 300,000 times fainter. The star´s feeble glow is the reason why it has not been seen until now, despite being relatively close.

"We discovered this star in September 2002 while searching for white dwarf stars in an unrelated program," said Teegarden. The team was looking for white dwarf stars that move rapidly across the sky. Celestial objects with apparent rapid motion are called High Proper Motion objects. An object of this type can be discovered in successive images of an area of sky because it noticeably shifts its position while its surroundings remain fixed. Since either a distant star moving quickly or a nearby star moving slower can exhibit the same High Proper Motion, astronomers must use other measurements to determine its distance from Earth.

INPUT: That sounds like they searched for PX, huh?

During its star search, the team used the SkyMorph database for NASA´s Near Earth Asteroid Tracking program, to search for asteroids that might be on a collision course for Earth. Pravdo is project manager of the asteroid tracking program and is principal investigator for SkyMorph, which was separately supported by NASA´s Applied Information Systems Research Program. Like High Proper Motion stars, asteroids reveal themselves when they shift their position against background stars in successive images. Automated telescopes scan the sky, accumulating thousands of images for the Near Earth Asteroid Tracking program, which have been incorporated into SkyMorph, a web-accessible database, for use in other types of astronomical research.

INUT: More confirmation they searched for something big and earth threatening at the PX site given by Nancy

Once the star revealed itself in the Near Earth Asteroid Tracking images, the team found other images of the same patch of sky to establish a rough distance estimate by a technique called trigonometric parallax. This technique is used to calculate distances to relatively close stars. As Earth progresses in its orbit around the Sun, the position of a nearby star will appear to shift compared to background stars much farther away -- the larger the shift, the closer the star.

The team refined their initial distance estimate with another technique called photometric parallax. They used the 3.5-meter (11.5 feet) Astrophysical Research Consortium telescope at the Apache Point observatory, Sunspot, N.M., to observe the star and separate its light into its component colors for analysis. This allowed the team to determine what kind of star it is. The analysis indicates it´s similar to a red dwarf star (spectral type M6.5) that´s shining by fusing hydrogen atoms in its core, like our Sun (called a main sequence star).

Once the type of star is known, its true brightness, called intrinsic luminosity, can be determined. Since all light-emitting objects appear dimmer as distance from them increases, the team compared how bright the new star appeared in their images to its intrinsic luminosity to improve their distance estimate.

Although the star resembles a M6.5 red dwarf, it actually appears three times dimmer than expected for this kind of star at the initial distance estimate of 7.8 light-years. The star could therefore really be farther than the rough trigonometric distance indicates; or, if the initial estimate holds, it could have unusual properties that make it shine less brightly than typical M6.5 red dwarfs. A more precise measurement of the new star´s position to establish an improved trigonometric parallax distance is underway at the U.S. Naval Observatory. This will confirm or refute its status as one of our closest neighbors by late this year. Either way, we might get even more company soon: "Since the survey only covered a band of the sky (about 25 degrees in declination), it is entirely possible that other faint nearby objects remain to be discovered," said Teegarden.

In addition to Teegarden and Pravdo, the team includes Dr. Thomas McGlynn of Goddard Space Flight Center; Dr. Michael Hicks and Dr. Stuart Shaklan of JPL; Dr. Suzanne Hawley, Kevin Covey and Oliver Fraser, of the University of Washington, Seattle; and Dr. Iann Reid of the Space Telescope Science Institute, Baltimore, Md. An image and more information are available at http://www.gsfc.nasa.gov/topstory/2003/0520newstar.html.

JPL manages the Near Earth Asteroid Tracking system and SkyMorph for NASA´s Office of Space Science, Washington, D.C. JPL is managed by the California Institute of Technology in Pasadena.

INPUT: Very interesting and suspicous

Using Farslayer's distance of a light year, the red dwarf is approximately 45.75 trillion miles away. For comparison, the Earth is about 93 million miles away from the Sun. Thus, this red dwarf is about 492,000 times as far away from us as we are from the Sun.

*Math experts, please feel free to correct me--it's been years since my last math class!

Too bad NASA is a disinfo agency.

I believe it's only 492x the distance.

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Luck? In my experience there is no such thing as 'luck.'

n/t

It would take the star's light (or other radiation, like heat) that long to reach us. The star itself is going much slower than light. For instance, it takes the Sun's light about eight minutes to reach Earth, but it takes many months or even years for a spacecraft to travel that distance. It's all a question of speed.

So if a star is 7 light years away, that means it takes light seven years to get to us from that star, and since light always travels at about 186,000 miles per second, that means the star is about 5,869,713,600,000 miles away. (Assuming I've done my math right. ) Even at the velocity of our fastest spacecraft, Voyager 2, it'll take an incredibly long time to travel that distance. Light years are very very very long distances. That's why interstellar probes are still a pipe dream. It's just a phenomenally huge amount of distance to cover.

So even if there was an object at that distance travelling on a collision course with Earth, I wouldn't worry too much. Our great-great-great-great-great-great-great-great-great-great-great-grandchildren won't even have to worry, really.

Uh, what do I mean? Ok dude, what's the deal here? You keep making posts in other threads about some pics you just happened to find that were stored in a directory that was strangely a lot like your handle here. So are you a PX follower or just really, really, really bad with math?

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Luck? In my experience there is no such thing as 'luck.'

Funny how ZetaDrones still cite their press releases, though.

No - he's right - it's 492,000. A trillion is 10^12, remember.

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Fin
Skep-ti-cult® member #488-28303-790

Ack, you're right, I skipped a whole set of zeros when I did my division. Thanks for finding that.

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Luck? In my experience there is no such thing as 'luck.'

it ould take a hell of a long time to get here

Okay, Skywatcher? What you're missing here is that the newly discovered red dwarf, the star itself, isn't traveling towards us--just the light that comes from it is. The star is 7 light years away, which means that the light that comes from it takes 7 years to get here, but the red dwarf star itself is still staying right where it is, 7 light years away, rotating comfortably, doing its own thing, completely uninterested in suddenly deciding to hurl itself towards a neighboring star and take out the third rock in its planetary system.

Repeat--there is no red dwarf star on a collision course with Earth.


Better now?