Stars Definition and 878 Threads

The technical paper (published in Nature): http://arxiv.org/pdf/1009.5992v1 The NYT journalistic account: http://www.nytimes.com/2010/12/02/science/space/02star.html?_r=1&ref=science ==quote== How Many Stars? Three Times as Many as We Thought, Report Says By KENNETH CHANG Published: December...

Hi, Actually, I would like to know the typical magnetic field in high mass stars. I tried to find in google, but I couldnt. Maybe I should try it harder. But if someone know a reference, I would be glad. Thanks, Joao A.

Hey guys. If the string theory is correct (and strings are fundamental and the last building block) I had a thought that if and when a star collapses (due to whatever reason) it can reach neutron star status. Add more mass and it can collapse to a quark star. Now say that we add more mass and...

I'm really stuck with this last question...im not quite sure where to start...any help would be greatly appreciated! for a) I am not sure what to use for the mass of the star and the radius..do i have to subtract the two radii? When a massive star is at the end of its life, the inner core...

I'm a high school physics teacher and my students are building a science payload to launch on a weather balloon. You can look http://www.donorschoose.org/donors/proposal.html?id=458390&challengeid=39361" to see some project details and even donate a couple bucks to help make the project a...

okay. i understand that stars can 46 million light years away despite the universe only being 13.5 billion years old. The universe is expanding. However what i dont' understand is how can we see a star that is say 20 billion lights years away if it takes 20 billion light years for the light to...

If a typical star is created by a spinning ball of gas, how does the gas start spinning in the first place to fuel that birth?

Is it possible for a cloud of gass to condense around a black hole and for fusion to start? Or another way to ask. Is it possible for a star to have a black hole at it's center?

If Hydrogen fusion starts around 100JM (Jupiter Masses) then how do the larger stars get so massive? I was watching The Universe and it said some stars are over 200 solar masses and higher. How can a star get so massive?

I'm not very good with words so if this seems redundant or not very well put together, know that i tried... I recently heard about white holes through an example of water from a faucet. The event horizon was a the ring of water that appears in the sink while the water is running. In the "even...

http://www.cnngo.com/explorations/life/mount-everest-has-no-wi-fi-and-too-much-snow-014380?hpt=Sbin ...and homogenous views: snow, snow and more snow.

hi, how does general relativity work INSIDE stars and planets, since the mass is no longer concentrated within a point, so there are necessarily gravitationnal effects outwards and not only inwards?

In a recent popular science account of "pair instability" supernova, a statement was made, without explanation, that if fusion of oxygen started producing sufficiently energetic photons that most of them convert to electron positron pairs, the the outward pressure is drastically reduced and the...

Homework Statement From the light and velocity curves of an eclipsing, double-lined spectroscopic binary star system, it is determined that the orbital period is 3.15 yr, and the maximum radial velocities of stars A and B are 5.2 km s^-1 and 21.6 km s^-1, respectively. Furthermore, the time...

Homework Statement One of the most massive binary star systems known is called WR-20a and is located in the Large Magellanic Cloud (a small companion galaxy to the Milky Way). This system is nearly edge on, and the stars are moving in circular orbits with observed speeds of 362.2 km s^-1 and...

seen a programe about super black holes in which some stars where orbiting them . speeding up as they are slingshoted around them or whatever the proper term for this is . so why if the black hole is strong enough to pull them in the first place why do they not get pulled in completely ... what...

I was wondering what would be the gravitational force caused by stars with high speed. As an example, I was trying to compute the gravitational force exerted by RX J0822-4300. This radio-quiet neutron star has a radial velocity of 1500Km/s (i.e. 0.5% c). The thing is that I am not quite sure...

Ok, the stars appear to move westword correct? Is that because the Earth is moving eastword, so its just an illusion that the stars move westword? Is this Newtons 3rd law? (every action has an equal and opposite reaction)

Why do stars appear to be white in color when viewed from the naked eye?

I've been trying to locate an algorithm to model the distribution of stars in a spiral galaxy. Simple, I thought, I'll just Google it. However I quickly disappeared up my own black hole! What I'm looking for is a simplified algorithm I can use to model n stars in a galaxy of size x (for...

I was out in my backyard performing some astronomic observations for azimuth and latitude and was treated to a few of the recent meteors. I have seen a few different colored ones and it got me to wondering. I have heard of red, blue, white and other colored stars, but don't ever remember...

a recursion to arrange a stars ! it's difficult :( hello ! :) my name is bella and i am still a student. I've instructed by my lecturer to create a simple program that will appear such as this output : Enter number of star : 5(user will key in the data) * ** *** **** *****...

I'm collecting information to write a science fiction novel set very, very far into the future. Without going into the plot, it attempts to explore concepts of isolation, eternity, and the collapse of the universe itself (modeled on the Big Freeze cosmological theory). To this end, I am curious...

hey everyone, I have one question. Has it ever been heard of, for a star moving at higher velocities, to be 'ejected'?. Especially if its on the fringes of the galaxy? Or if two galaxies where to collide, wouldn't it be plausible, for stars and be swept away into empy space outside of any...

It is a question i have been thinking about for a while. When we look into the sky, are we actually looking at other stars or are we looking at our own sun from lots of different angles, we know light bends with the gravitational pull of planets. is it not possible that the light we see from...

R136a1, is a blue hypergiant star Reference: http://en.wikipedia.org/wiki/R136a1

When did the first stars form? When did the first photons form?

How hard is it to detect stars say of a tenth the solar mass, I know it depends on the distance of course, but how frequently do we spot these kind of stars ,moreless?

Does electromagnetic radiation emitted by pulsars carry enough energy as to make the gravity created by these emissions significant enough to gravitationally effect distant objects many light years away? In other words, can a pulsar star or a neutron star, effect distant planets or even...

Hi Guys .. I have a question and I hope I get a good and obvious answer PLZ .. How do stars and moon look like from outside the Earth's atmosphere ? If we went out of the atmosphere of the Earth , will we see the stars in the same way as we see them from .. here ? In other words do the...

can anyone tell me about various stages of life of a star? when does a neutron star, supernova, pulsar form?

I heard on a recent podcast that most astronomers and physicists of the early 20 th century, if they thought about it at all, believed that the universe always existed, i. e. it had no beginning. Even Einstein accepted the Steady State Theory, along with many others. How did these astonomers...

Hi I want to know how astronomers count the number of stars (or any other celestial object for that matter) in the sky. Will they take a photograph and do some signal processing like counting the number of brightest spots? Is it possible to count accurately since there are billions and...

Any ideas appreciated!

If black holes are not real, just wondering? By the way they may or may not exist. But since some people don't believe they exist and some do, then if you DO NOT , how do you explain what happens to neutron stars that are 20 -25 the size of the sun? typo in the title, it should read: " what...

If, for argument sake, you had a spaceship that could go thousands of times the speed of light what would happen to the electromagnetic radiation being emitted from the stars you head towards and away from? Would the stars that you are traveling towards get duller and duller the faster you go...

I always here about neutron stars and black holes sucking the gs from their companions. However, a star loses mass before it becomes a neutron star so I don't understand why it afects its neighbor more when it is a neutron star than when it was a regular star.

Does anyone know why it is the goal to achieve 5 stars in something? Why not 3 or 6 or 9 or 358? I personally would have started the trend at getting 6 stars, being that it's a perfect number and all...

Hi! my question is, if space expand, how come the stars (and planets) don't? they are part of the space and not "sitting inside" or somthing like that. meaning, the Earth should grown bigger all the time. you can think about marking a dot on a bloon, as you blow air inside the bloon starts...

Why do starts blink and planets do not. There are some stars that are just as bright as a planet(unless my observation is wrong). I know the light from the star enters Earth's atmosphere and due to the variation in density(which means change in dielectric constant of the medium in which light...

[urgent] finding mass enclosed my a stars radius from center. Homework Statement the rotational speed of an orbiting object is given by v= (Gm/R)^1/2where R is distance at which the object is rotating from the center of the mass distribution and M is the amount of mass within the radius R...

Homework Statement Using a telescope with circular aperture of diameter 2.5 meters and wavelength 463 nm. The stars are 10E22 meters away from us. What does the distance between them have to be so we view them as two stars? Homework Equations angle = 1.22 x (wavelength/diameter) >...

Ive noticed every time i see a picture of the ISS or astronauts working in outer space there is NEVER any visible stars? Why is this? i been told that they filter it somehow since they stars would be so bright, or is there another reason this has been on my mind for a long time

Wikipedia says that the core temperature of our Sun is 15.7×10^6 Kelvins. I don't know what that means in terms of protons' velocities inside the core, but I bet they move pretty fast. Could they move that fast that they have a noticeable increase in mass due to their relativistic speed...

Hi, Does anybody know a place where i can find a list of electron densities of stars?

I always wondered why we see light from stars. If the light travels outward in all directions from a star then you could imagine the light as a growing sphere and the portion we see is a small area on the surface of this sphere. Well if a star is a million light years away this would mean the...

"Electroweak stars: how nature may capitalize on the standard model's ultimate fuel," De-Chang Dai, Arthur Lue, Glenn Starkman, Dejan Stojkovic, http://arxiv.org/abs/0912.0520 Pretty far out, and I'm not sure I believe it. One thing that surprises me is that they claim the standard model has...

Homework Statement Two equal spherically symmetrical stars, A and B, each of mass M and radius r have their centers 6r apart. Make a sketch showing the lines on which the gravitational potential takes the values: 1. \frac{-10GM}{11r} 2. \frac{-2GM}{3r} 3. \frac{-GM}{3r} Accurate plotting...

Please help me with this question. Thanks

Ho :), I would like to know how exactly stars and galaxies are spread out throughout the universe. Are stars only found within galaxies? How many stars are without any planets? Whats the average number of planets in a star with planets? Whats the maximum/minimum number...