The Universe, a size comparison

[Arlos]

OK, found these images online, and thought they were pretty cool and really illustrative.

Now, most people here know that I used to be an astronomy (well, astrophysics) major, and it's still one of my biggest interests. In the past I've had trouble getting across just how big some things are out there, and the scale of the rest of the universe to us. These fix that problem.

OK, the first picture is Earth and the rest of the terrestrial (ie, rocky and solid, not gaseous) planets, plus pluto, which may or may not be a planet depending on who you talk to.



OK, now we have relative sizes if you include the rest of the planets of the solar system:



OK, still our solar system, but we scale everything by the Sun.



OK, now that we have the image in our head of just how big the sun is compared to everything in the solar system, including the tiny speck there that is earth, our next picture is of the Sun vs some well-known nearby stars.



OK, and in our last picture, we compare those to some actually decent-sized stars on the scale:



Antares, the biggest star in these pictures is the 15th brightest star in our sky, and is about 15.5 times the mass of the Sun, and has a diameter that is about 700 times larger. While good sized, stars can get much, much bigger. The biggest star known is nearly 3 times the size of ANTARES, and weighs up to 100 times as much as the sun.

Anyway, hope at least some people find these as interesting as I did.

-Arlos

[Maeya]

Are these all in the Milky Way Galaxy, still?

It's hard to wrap your head around, but fascinating to think about at the same time. Pretty insane to think that those stars are mere specs in our galaxy, and there are so many galaxies out there in the universe. I don't consider myself a stupid person, but seems incomprehensible.

[Juls]

Sun is very very small but already burning us all..

[Arlos]

Yes, these're all in the milky way. Aldebaran in the last picture is the red star that is the eye of Taurus the Bull. You can find it pretty easily by following the line formed by the 3 stars of Orion's belt out straight, and you'll run right into it. It's at the top of the V of stars that is Taurus' face. Betelgeuse is Orion's back shoulder.

Go to http://www.biochem.szote.u-szeged.hu/astrojan/orion.htm and see. The blue stars in a row at an angle are his belt, the bright orange one in the upper left is Betelgeuse, the blue stars in a row below the belt are his sword (on his belt, and where the Orion Nebula is where that famous "Pillars of Creation" picture that Hubble took is from. ( http://sci.esa.int/science-e-media/img/07/6550.JPG ) BTW, those pillars completely dwarf ANY star), and the other bright blue stars mark his legs, etc. Should be fairly obvious.

The Milky Way galaxay is made up 200-400 BILLION stars, and would look like this:
http://upload.wikimedia.org/wikipedia/c ... y_2005.jpg

if you could see it from "overhead". In that picture of the Milky Way, Betelgeuse might be one of the barely discernable specs of individual light you can see. Maybe. But it probably would be too small to stand out overmuch.

-Arlos

[Jay]

Interesting stuff. What's the one that's 3 times bigger than Antares called? Also, how do we know this shit exists? Not doubting it, but I'm saying I don't know how the scientists came to these conclusions.

[Xaiveir]

Great stuff man. I love astronomy, it was my favorite subject i took in college. I wish more people i knew, were interested in it.

[Tossica]

Yeah man, I love astrology too! What's yer sign?

[Xaiveir]

Yeah man, I love astrology too! What's yer sign?

Capricorn baby....what are you doing later? Wanna cyber?

[Tossica]

Yeah man, I love astrology too! What's yer sign?

Capricorn baby....what are you doing later? Wanna cyber?

I'm wet just thinking about it.

[Xaiveir]

I put on my robe and my wizard hat..........

[vonkaar]

Interesting stuff. What's the one that's 3 times bigger than Antares called? Also, how do we know this shit exists? Not doubting it, but I'm saying I don't know how the scientists came to these conclusions.

This will be an interesting thing to type up on a Friday night at 2:00AM...

You can find all sorts of neat things about stars simply by 'looking' at them. The standard stellar properties are magnitude (brightness), distance, temperature, size, mass and composition. We can figure all of this, and more (such as, where it's going and how fast it's getting there) just by "looking" at it. Distance is figured with trigonometric parrallax. This is a surveyor's bread and butter. This doesn't work for all stars, but it'll suffice for now (the other method to find distance is called the inverse square law of light brightness). We know what it's made of (composition) by a half century-old technique called spectroscopy. Combine this with the doppler effect and you get doppler shifts, which tells you the motion of the star (velocity, and more). We can figure out temperature by using Wein's law, which (baaaaaasically) links color to temperature. The hottest objects are 'bluer' than the colder objects. We can also determine a star's mass by observing the orbital motions of binary stars.

What did I miss? Mass, temperature, motion, composition, distance...

I'm tired...

[Tacks]

Didn't we have a picture here once comparing "Vonkaar's Wang" to the Universe?

[araby]

Didn't we have a picture here once comparing "Vonkaar's Wang" to the Universe?

yes.