Star Definition and 1000 Threads

I was listening to the regional NPR station yesterday and hear a brief discussion of two binary systems. http://stardate.org/radio/program.php?f=detail&id=2009-12-26 Is this common? Is it plausible? I presume that some how the velocity of Mu Columbae and the other star traveling 'north'...

Homework Statement The questions are about binary star system. Homework Equations Why the two stars in a binary star system are always diametrically opposite positions? Why the two stars have common period? Why the inner star is more massive? The Attempt at a Solution For the...

http://arxiv.org/abs/0912.3229

Please could you let me know how to find out apparent magnitude of a star when you know the apparent magnitude of the binary star system? p.s. the distance between the observer and the system is'nt given. I have the luminosities of both the stars as well as absolute magnitudes of both the stars.

Homework Statement The spectral lines in a low mass main sequence star show sinusodal velocity variations with an amplitude of 500 km/s and a time period of 10 hours calculate a lower limit to the mass of the unseen binary companion Homework Equations M1 + M2 =...

Sorry no one was answering my question, and I just wanted to get this done: Homework Statement ...Hence show that the mass of the star is M = 4\pip_{c}\left(R^{3}/3 ) Homework Equations M(r) = 4 \pip_{c}\left(r^{3}/3 - r^{4}/4R) This is the mass within a radiusThe Attempt at a Solution I...

Homework Statement ...Hence show that the mass of the star is M = 4\pip_{c}\left(R^{3}/3 ) Homework Equations M(r) = 4 \pip_{c}\left(r^{3}/3 - r^{4}/4R) This is the shell massThe Attempt at a Solution I already found the shell mass via intergration, and I know that I have to build up an...

What is different about the photons from a star compared to something man-made which allows it to travel so far?

Orbital Speed of a Star - Please Help! Homework Statement Calculate \Omega(r) and v(r) for the following density models: (a) all the mass M is at the center of the galaxy; (b) a constant density adding up to a mass M(R0) at the Sun’s orbit and no mass beyond. Homework Equations...

I am having trouble understanding how stars orbit around a spiral galaxy. First off, my understanding of the Local Standard of Rest (LSR) is that it is a point which corresponds to the average velocity of all the stars in the defined local neighbourhood. This point moves around the centre of...

Homework Statement Let’s make an idealized star model with two parts: an isothermal helium core, and pure hydrogen layers outside the core. The core represents the part where hydrogen has already been burned. Mathematically this represents the simplest model that might resemble a...

I understand that a great number of star's we see are no longer there (now dead)we are just seeing the light traving from them over the vast distense of space, Question If I were looking into the sky at night and seeing start light from a now Dead star and someone else (you) at the same time...

A star's surface sends out energy in form of electromagnetic radiation and has an emissivity close to 1. Find the solar radius of Rigel that emits energy at a rate of 2,7 * 10^32W and has a surface temperature of 11000K. You may assume the star is spherical. Attempt at solution: Formula for...

it is known that there is considerable lag time when light travels from some place and reached us her on earth. is it possible that what we consider to be star formation actually nothing more than us receiving their light for the first time? thanks in advance.

The moment before a neutron star collapses matter is distributed across the whole volume of the neutron star? Can we say anything of the actual collapse, such as matter moves towards the center of the neutron star?

Say we slowly add mass to a neutron star till it collapses to a black hole. Just before it does has time in the neutron star almost come to a stop? Is the passage of time different for different locations in the neutron star just before it collapses? Would the strings of string theory come to a...

Homework Statement I'm to prove that the central pressure of a particular star is Pc = (15/16\pi)(GM2/R4) I am given the density as a function of r \rho(r) = \rho0[1 - (r/R)2] In part a I found the Mass by integrating the equation of hydrostatic equilibrium and found M =...

Homework Statement A binary star system has a period of 90 days. It consists of two equally massed stars each with a mass of twice that of the sun, that rotate like a dumbbell about the center of mass at the midpoint between them. How far apart are these stars? Homework Equations F =...

Is there a way to estimate the mass of a star using Spectral Class and absolute magnitude? If you can't then what info do I need in order to so. Thanks, Dan

Homework Statement 2 stars rotating around the common centre of mass have masses m and 3m. What is the ratio of the force due to each star at the common centre of mass. Homework Equations None The Attempt at a Solution I tried to find the centre of mass and applied Newtons law of...

Im really trying to learn CFD since embry riddle does not have a good course for undergrads to learn some basics about viscous flow..Im really trying to learn CFD since aerodynamics in general interests me alot. Does anyone have good resources to learn some CFD software ( namely star design ...

I have a question in an assignment that says "Estimate the central pressure of 0.5, 1.0, and50 solar mass stars. Compare these pressures to the central pressure of the sun" I can estimate for the sun using the Hydrostatic equilibrium equation: dP/dr = -GM(r)p(r)/R^2...

Hello, I was given a question in school that says use the hydrostatic equilibrium equation and mass conservation equation to come up with a lower limit of the central pressure of a star at it's centre. Here is how I think: 1) Refer to the density in both equations as the same and sub...

Might there somewhere in the galaxy by a star with a giant set of rings, just like those of our own saturn, only much bigger?

I am looking for star catalogs of stars within 200 lys of Earth for a project I am working on. I would like to have them as .csv, but any table format should do. I'll need such info as name, dist, mass, luminosity, spectral type, galactic coords or RA and Dec., radius. So far my attempts at...

If a neutron star accumulate materials from its companion star ,then it's mass exceeded Tolman–Oppenheimer–Volkoff limit, it will collapse into a black hole! My question is ,in this case ,it will produce "gamma-ray burst"?

How many neutrino emission mechanism, that causes the cooling of star, are there in neutron star? And How, what equation, to calculate the emissivity of each mechanism? thankfully, First

[b]1. The two components of a double star are observed to move in circles of radii r_1 and r_2. What is the ratio of their masses? (Hint: Write down their accelerations in terms of the angular velocity of rotation, w) The answer is m1/m2 = r2/r1. How does one cancel the velocity from the...

Hello Friends I need little help pleasezz :redface: How Can I solve this circuit? Which things first I have to find. And how. Problem Statement is. A. Average power of each phase load and total Load. B. Determine the reactive power of each phase and total reactive power C. Find the...

If gravity slows light, would light be pushed faster away from a star that has less gravitational pull? Would we still observe it at c?

Hello, Sorry if this is not the right place but I'm trying to find this for days now... I'm trying to find a working formula to determine the position (r.asc/decl) of a star at any given time and for a specific location on earth. So the parameter would be: R. Asc. of the star...

Hi everyone, Firstly i want to say that I've watched some of the "The Universe" episodes on my computer, and i pretty much have basic knowledge about the cosmos. But there's only one thing in particular that I'm confused: the life of a star. I pretty much know the "core" of it, but i can't...

Ok, I'm watching all of the episodes this season. This seasons does seems to be going better, they are eliminating the duds upfront, which is a nice change. They canned that weird health food nut this week. The next person I want to see go is Jamika. She is so fake when she gets in front...

How do I calculate the mean phase-weighted intensity magnitude of a variable star? I.e., if I have binned (magnitude) data points over the whole light curve, how do I change those magnitudes to intensities so that I can get the average intensity and then convert that value back to a magnitude...

Star clustering... (Help me...) Here goes...:cry: I am currently taking a BS Degree in Applied Physics and I do need someone's help right now. My research is all about the clustering of stars... Frankly speaking, I don't know where to start. I just first want to organize my thoughts and step...

Just saw Star Trek like an hour ago with my friend and it was great! :biggrin: I've never actually seen the show but I think I can make time. How did you guys like it?

It's well known that white dwarf stars are supported by degenerate-electron pressure. Calculation shows that maximum mass of white dwarf star is about 1.4 solar mass. My question is why it has a maximum mass? The postulate of Quantum mechanics says that it should be a distribution of mass...

Homework Statement 28. Calculate the quadrupole tensor I_{jk} and its traceless counterpart \overline{I}_{jk} (Eq. (9.78)) for the following mass distributions. (a) A spherical star whose density is \rho(r, t). Take the origin of the coordinates in Eq. (9.73) to be the center of the star...

Hello my name is Kristoffer and I am new here :) I have made a spreadsheet in MS Excel to compare star-data and need some help try it out. Testing. This filesize is about 15 mb (4,5mb zip-packed) I have not taken any astronomy class or something like that. So I am not 100% sure the...

Hi, When the core of a star shrinks during its evolution, does it always lead to the expansion of the star? If not, why? What cases would cause it to expand? Thanks in advance, Maria

I am doing report and I need to know how fast it will take you to get to the nearest star at .5c? Thanks.

http://www.imdb.com/title/tt0796366/ Double-click to watch the trailer https://www.youtube.com/watch?v=7w4vk5OZmn8 Expectations? It looks like they use my idea of a reentry suit.

Homework Statement "The mass of a star is 4.85x10^29kg. In scientific notation, Kepler's constant for that star is bx10^w s2/m3. the value of b is_____." Homework Equations K=T2/r3 The Attempt at a Solution This problem is very tough. I first assumed that K would be 0 because the...

What's physically stopping all the fuel fusing at once or rather each stage of its fuel cycle fusing into the next quickly? i know there's a lot of it and gravity holds it together but what are these atoms doing while they wait to under go fusion exactly? They are after all under the same...

https://www.youtube.com/watch?v=Il5TBgD9kHI Whoops, use this link: http://www.youtube.com/watch?v=Il5TBgD9kHI&eurl=http%3A%2F%2Fwww%2Ephysicsforums%2Ecom%2Fshowthread%2Ephp%3Ft%3D307427&feature=player_embedded

I'd like to create a catalogue of stars that are within a one degree belt along the ecliptic. Since most databases use RA/Dec coordinates, this appears to be a daunting task. Any suggestions?

If someone had a superstrong chamber that could withstand anything (hypothetically) if they constantlty fed the correct materials at the correct state into the chamber could they create a mini self sustaining star?

Homework Statement A certain star is 13 million light-years from Earth. The intensity of the light that reaches Earth from the star is 6 10-21 W/m2. At what rate does the star radiate EM energy? Homework Equations i know you have to convert lightyears to m. (1.23e17m) multiply this...

Problem about "binary star system" Homework Statement About half of the visible "stars" are actually binary star systems, two stars that orbit each other with no other objects nearby. Consider the motion of the center of mass of a binary star system. For a particular binary star system...

I need to work out the luminosity of 3 stars 85 PEG A / B / C using the following data and equation, Absolute Mag of stars A/B/C/SUN MA = 5.28 MB = 8.53 MC = 15 MS = 4.84 Apparent Mag of stars A/B/C mA = 5.75 mB = 9.00 mC = 15.47 LS = Luminosity of Sun – 1 ? Equation MA-MS =...