Stars Definition and 890 Threads

You know how the stars move as the night progresses. Well is it the declination that is varying with time? I don't think that it's the right ascension because with that you measure the angle from the vernal equinox to the point of intersection of the star's meridian with the celestial equator.So...

http://arxiv.org/PS_cache/astro-ph/pdf/0502/0502385.pdf No kidding. Would anybody here like to hazard a guess at where this "reddening dust" lies on the path between the z~6 galaxies and our vantage point? If the "reddening dust" is very ancient and distant, I would be interested in hearing...

It's used to remember the order from brightest (hottest) stars to the dimmest (coldest stars). I remember that it starts with Oh,... then in the middle it maybe be: " Be It A Fine..." Boy/Girl, Kiss Me! So the order is like O ... B G K M It's driving me nuts; please help me!

Stars are known t0 flicker. a) estimate the no. of photons entering the eye of an observer when he looks at the star of first apparent visual magnitude. Such a star produces flux on the surface of the Earth of 10^-6 lumens/sq.meter. One lumen is 0.0016 watts. Star Aldebaran is an example...

In the Milky Way?

http://arxiv.org/abs/astro-ph/0507593 Title: Core-Collapse Very Massive Stars: Evolution, Explosion, and Nucleosynthesis of Population III 500 -- 1000 $M_{\odot}$ Stars Authors: T. Ohkubo, H. Umeda, K. Maeda, K. Nomoto, S. Tsuruta, M. J. Rees Comments: 46 pages, 45 figure files We...

What are they? :confused:

How big can these stars get, Also can a star be born at a Supergiant level? I'm having a hard time understanding a particular object. The Helix Nebula is said to be the result of a supernova explosion, a closeup reveals tiny knots of gas, now these knots are said to be at least the size of...

why variable stars have various magnitudes? and y they are changing periodically?

I have a question about the time scale for a certain type occurance causing a neturon star to explode, and a related question about the conditions of this occurrance. If you have a binary star system with one of the stars being a neutron star, I read that if the other star sucks off enough...

quasars are highly active but extremely distant galaxies, right?what kind of galaxies are they and do they represent an earlier stage of the lives of the conventional galaxies?i've a vague idea that quasars a galaxies in which the supermassive black holes at the centres are actively gobbling up...

Especially in the early universe, what do you think would be the maximum number of stars bound in a system under mutual attraction?

Are Neutron Stars the major factors of Proton Stars? :http://arxiv.org/abs/astro-ph/0506092 Why do Neutron Stars evolve from Proton Star collapse, and what is the next evolving stage?..if any? :http://arxiv.org/abs/astro-ph/0506100 Can a further collapse occur that does 'not' produce...

http://arxiv.org/PS_cache/astro-ph/pdf/0505/0505524.pdf Title: The first chemical enrichment in the universe and the formation of hyper metal-poor stars Authors: Nobuyuki Iwamoto, Hideyuki Umeda, Nozomu Tominaga, Ken'ichi Nomoto, Keiichi Maeda Comments: To be published in Science. 12...

http://www.physics.ubc.ca/~heyl/ns2005/prospectus.html Neutron Stars at the Crossroads of Fundamental Physics I. Organizers Jeremy Heyl – University of British Columbia Vicky Kaspi – McGill University Feryal Özel – University of Arizona Krishna Rajagopal – Massachusetts Institute...

Straight forward questions that's been bugging me a little. Why do most stars lie on the main sequence whilst others don't? Is it just purely characterised by the mass? Thanks

Where can I find PDF "Black holes White Dwars and Neutron Stars" Gents, Could u pls advise me if you know where can i find book "Black holes White Dwars and Neutron Stars" Authors Shapiro, Tuekolsky (free PDF or DJVu or other format) Thks

What are the forces that give asteroids their shapes? And what shape do neutron stars that do not rotate around its axis have?

Is it possible, say, for a world like Earth (or, at least enough like Earth that people could live there without space suits, etc.) to orbit a Red Giant star? What would such a world be like? \phi The Rev

one reason it's good is that it is written for the Wiley "Encyclopedia of Physics" http://arxiv.org/abs/physics/0503245 Neutron Stars Gordon Baym, Frederick K. Lamb Comments: Encyclopedia of Physics 3rd ed., R.G. Lerner and G.L. Trigg, eds., Wiley-VCH, Berlin Abstract: "This short...

Here is my problem: The star is 59 light years from the Earth and has a mass of 1.90×1030 kg. A. A large planet of mass 1.20×1028 kg is known to orbit this star. The planet is attracted to the star by a force of 3.50×1026 N when their centers are separated by a distance equal to the...

AKA solar systems rare?

Alright, I just need to find the density of three stars in g/cm^3. I have been given the following information: Density of a star = Mass / ((4/3)*pi*Radius^3) First star is a white dwarf: Mass = 2 * 10^30 kg Radius = 5000 km Second star is a neutron star: Mass = 2(2 * 10^30) kg...

First star-forming gas clouds were much denser. (Early Universe was smaller and prior to stellar fusion also had more hydrogen.) Did not most first generation stars leave Black Holes behind when the rapidly completed their life cycle? How much did the universe expanded while the first stars ran...

Can and do they exist primarily separate from ordinary matter, and how might they be detected (e. g., gravitational lensing, Newtonian mechanics)?

Are there still stars being discovered? I mean are there stars whose light has not reached us. I think that is only possible if after the BIG BANG matter traveled away from each other with more speed than the speed of light.

Could it be that all the stars we see in the sky no longer exist?

The distance between stars is measured by the time it takes light to travel between them correct? How do you measure the time it takes? for example from CNN "It is 12.7 billion light-years away, meaning the light just recorded -- by NASA's Chandra X-ray Observatory -- took 12.7 billion...

Sooner or later its bound to happen. Has there been a recent observed colliding force between two stars in our Galaxy? i'm keen to see a collision between a red star and a blue one to know what colour the end star will be. E

Hello, Well let me give a pithy description of what’s going on. There are 6 fixed stars (constellation) within a building and an observatory, which is the only place measurements of distances and positions can be calculated. Now I need to find the distance to each start using parallax methods...

Out of the primordial hydrogen, what were the largest star and smallest galaxy that eventually formed?

I was reading about the greatest mass that stars can have http://arxiv.org/astro-ph/0501135 it is not 100 percent sure but 200 solar masses looks like an upper bound on the mass it is also not certain why. if there is some upper limit, say between 130 and 200 solar mass, then WHY...

I was reading somewhere that the because of the red shift it can be concluded that the galaxies are moving away from us. But still when we talk about stars, red color refers to cooler stars rather than stars moving away from us. Why?

Another interesting release: Astronomers reveal biggest stars yet seen http://www.newscientist.com/article.ns?id=dn5046 It just keeps getting weirder when you look far enough back. Modern theory is sometimes frighteningly accurate.

A little confused, could someone explain what it means when it is said that "the point in a body or a system of bodies, at which the total mass of the body or system may be regarded as concentrated".(definition of Center of mass) What does it mean concentrated? I'm trying to understand the...

suppose we look to distant galaxies or stars tru a telescope like hubble. We can see an image of the star becouse it's emiting photons and this photons are reaching the Hubble telescope... Knowing the size of the universe, the size of the star, the size of the Hubble telescope, and it's...

As I type this, I listen to “The Zephyr Song” by Red Hot Chili Peppers, and I have just begun to contemplate odd ideas. I don’t understand why I feel some sort of awkward attraction for the life of rock stars -- especially eccentric, intelligent, and such wild ones. I am a practicing Christian...

Does anyone know a good web page for becoming familiar with the night sky... and where certain stars should be etc..?

It seems that planets can not exists around twin-stars or even triple-stars. I mean that the planet orbits both stars, and not just one of the two/three. Why is that? The planet can just circle around the centre of gravity, what is so special about a twin or triple-star system?

http://www.mpe.mpg.de/ir/GC/images/movie2003.mpg four stars photographed (timelapse over years) doing various type orbits around the million-solar-mass hole at the center of Milky one doing elliptical, one kind of long skinny parabolic, one on what looks like a one-shot hyperbolic...

Einstein field equation gravitational potential: \nabla^2 \phi = 4 \pi G \left( \rho + \frac{3P}{c^2} \right) General Relativity gravitational pressure: P_e = \frac{c^2}{3} \left( \frac{\nabla^2 \phi}{4 \pi G} - \rho \right) Classical Yukawa Pressure: P_y = f^2 \frac{e^{-...

in some photos, mixed among the red white and blue stars, are green stars. Any idea what causes this?

Is the parallax method still the one most widely used (for the relatively nearer stars at least)? More particularly, is it still the case that we take one measurement then wait six months until the Earth is on the other side of the sun and take a second measurement? Or has this been superseded...

If neutrons stay intact and get closer together than 10^-15 metres in a neutron star, would the exchange of mesons between neutrons stop and be replaced by the exchange of gluons, and would the gluons cause an attractive or repulsive force between neutrons? A repulsive force could stop the...

What process within a star causes it to emit electromagnetic waves (light, x-rays etc.)? What is the source of the electricity / magnetism inside the star?

Why can't the Earth's magnetic field go bazooka! It's made of iron and it's got poles...

Hi, i read something about light turning red due leaving gravitational fields. A long time ago i played a game called ascendancy which was about colonizing solarsystems and battling other species and they had a few different kinds of stars in it, a few of these where white and blue dwarfs and...

Why do Some Stars Explode ? It is a fact that stars do explode. But why? Cosmological theory says it is caused by the acquisition of mass beyond the Chandrasekhar limit. My hypothesis is that explosion is related to an intrinsic metric variable. This variable is the parameter for all possible...

An article by W Tucker and K Tucker at NASA says that neutron stars have magnetic fields. If a magnetic field is created by moving charges, and neutron stars have not net charges to move, how are the fields created?

An interesting question has arised from one of the discussions around here: are there any stars that have a highly eccentric elliptical (or even parabolic/hyperbolic) orbit around the center of their gallaxy, somewhat like comets have in our solar system? And for that matter, are there any stars...