Star Definition and 1000 Threads

Homework Statement An astronomer observes a hydrogen line in the spectrum of a star. The wavelength of hydrogen in the laboratory is 6.563 x 10-7m, but the wavelength in the star’s light is measured at 6.56186 x 10-7m. Which of the following explains this discrepancy? A) The star is...

Homework Statement The light from a star reflects from a concave mirror with a radius of curvature of 1.70 m. Determine how far the image of the star is from the surface of the mirror. Speed of light = 3.0 x 10^8 m/s r = 1.7 m f = 0.85 m 1/di + 1/do = 1/f... and then I'm stuck b/c...

Why doesn't a star collapse in the early stages of its life instead of the later. You would think that with less gas at the end stages gravity would weaken and not allow a black hole.

Is it possible to calculate the radii of a star knowing its mass, luminosity and effective temperature? Thanks

http://starwars.com/ I remember standing in line for hours to see this... and I don't think it was even opening day. wikipedia.org: Star Wars IMDB: Star Wars Stamps from USPS: http://www.uspsjedimaster.com/

Homework Statement In a star Trek episode, a space station orbiting a planet blows up. The chew of the Enterprise simultaneously hears and see the explosion; they realized that tehre is no chance for rescue. If you have been hired a consultant, what two physics errors would you have found and...

Hi guys - Here's the problem I am chewing on: A binary star system consists of two stars, each equal to the sun in mass. The distance between the two stars is 1.0 X 10^12m. A comet which is essentially at rest, begins to make its journey toward the binary star system as a result of...

Has there ever been an observed star collision? If there hasn't, what might occur?

If the universe is expanding, then the brightness of distant stars should gradually decrease. Did anyone observe this phenomena of fading star light ?

so much for trek being dead for a long long time... and staring matt daemon as Kirk! http://imdb.com/title/tt0796366/ http://movies.ign.com/articles/767/767783p1.html

Homework Statement Last part of MTW Gravitation exercise 23.7: Calculate in Newtonian theory the energy one would gain from gravity if one were to construct a star by adding one spherical shell of matter on top of another, working from the inside outward. Use Laplace's equation d(r^2 (d...

What an incredible story: An unpopular and short lived series refuses to die, and now, along with its offspring, Trek spans forty years that have inspired countless young minds. http://www.startrek.com/startrek/view/series/ [The History Channel is currently running a two-hour documentary...

This problem deals with two main sequence stars in an eclipsing binary star system. I need to determine the system's peiod and separation (P and a). Right now i know that the brightest star has an absolute magnitude of -1 (219 solar luminosity), is 17,000 degrees kelvin, has a radius of 1.74...

Has anyone ever been to one of these? I'm going to one for the first time this saturday and I'm just wondering what to expect. What exactly goes on? Do they just set up the telescopes pointing to different celestial objects and you go around looking through each one? I am majoring in...

Homework Statement A B0 star has a luminosity of ~ 16000 L(solar) and a mass of ~ 16 M(solar). Can you estimate the time on the main sequence for this star simply from considering the rest mass energy of the core of the star (~10% of the total, and fusion burns with an efficiency of about...

I am in Astr. 1020, and in my introductory Astronomy class I had last semester, we didnt learn anything. It was a "here's the study guide (aka the answers to the test)" kind of class so I didnt really learn that much. Now, my Astr. 1020 teacher is rather difficult due to what I didnt learn...

What would happen if Saturn had become a second Sun in the formation of our universe? Would Earth have ever come to the way it is now? What would happen if it all of a sudden became a sun this very instant? All comments are appreciated!

I was wondering how far away the stars are at night that can be seen by the naked eye. I would venture to guess that the galaxies that are billions of light years away must be seen with a high tech telescope. o| Hiram

OK, so probably only me and Ivan will laugh at this but what the hey.. man, that Saurian brandy will mess you up!

I am reading some books about differential forms. I don't quite understand what is the geometrical meaning of star (hodge) operator. Can anyone give me a hand please? Leon

Homework Statement A star in the long jump goes into the jump at 12 m/s and launches herself at 20.0 degrees above the horizontal. How long is she in the air before returning to Earth? (g=9.81 m/s2) Homework Equations first I look for the v0(cos) and then I look for vfy= v0(sin) I...

Homework Statement Suppose the sun collapses into a neutron star. What will its radius be? The questions also gives some backround explaining that stars fuse hydrogen into helium until they collapse into a neutron star. The protons and electrons fuse into neutrons with the density of nuclear...

The question is: Suppose the sun collapses into a neutron star. What will its radius be? The question gave a brief backround explaining that stars are powered by nuclear reactions that fuse hydrogen and helium. When the hydrogen is used up the star collapses into a neutron star. The force of...

Build your own death star here: http://www.deathstardesigner.com/ Here's mine: http://www.deathstardesigner.com/station/5224

A neutron star has a mass five times that of Earth and a 10 KM radius. Find the distance from this star's surface a satellite must be at to stay in a circular orbit if the satellite is moving at 50000 km/min. First, I changed the 10 KM to meters and found the mass of this neutron star...

The gas cloud known as the Crab Nebula can be seen with even a small telescope. It is the remnant of a supernova, a cataclysmic explosion of a star. The explosion was seen on the Earth on July 4, 1054 AD. The streamers in the figure glow with the characteristic red color of heated hydrogen gas...

where does all the mass go?

Pllllease help me I have been stuck on this for ages: [HRW5 14-57E] A star, with mass 3.29 1030 kg, revolves about the center of the Milky Way galaxy, which is 3.33 1020 m away, once every 2.17 108 years. Assuming that each of the stars in the galaxy has a mass equal to that of our star...

A star has radius R=1.90x10^9 m and surface temperature T=15,200K. How much power does it emit in the range 500 nm < lamda < 510 nm?

Hello I have a question that is giving me trouble: Light of wavelength 659.7 nm is emitted by a star. The wavelength of this light as measured on Earth is 661.1 nm. How fast is the star moving with respect to Earth? km/s Is it moving toward Earth or away from it? Here's where...

Does anyone know of a good reference regarding solving the Tolman-Oppenheimer-Volkov equations for neutron stars? Most things I find are either too elementary and others skip multiple steps. I think the EoS to use should be that of a Fermi gas model, but I am not sure.

anyone going to buy it? i mean, it's the ORIGINAL THEATRICAL CUT ON DVD! i already got a new hope, and i mean to have empire by saturday. anyone?

This was one of my test questions today. Read it carefully. A viewer knowledgeable in the science of fiction watching Star Wars can safely assume that: A) The rebel heroes can see the light of an explosion in outer space. B) The rebel heroes can hear the sound of an explosion outer...

I hope some of you will be able to help me. First, let me make sure I have this right. From what I understand, the five Pole Stars are: Polaris Al Deramin Deneb Vega Thuban My question is, what was the Pole Star between 9,000 BC and 10,000 BC? The length of time for each Pole Star...

For those who like the original series, you might get a kick out this. Star Trek Fan Films Live Long and Prosper http://www.npr.org/templates/story/story.php?storyId=5573621 Now those are dedicated fans.

I'm wanting to look at a bright star catalogue and I've been told to use something pronounced as visy-ar. I've typed 'visear', 'visiar' and some other spellings in google and can't find the site. Does anyone know the link at all and how the name of this database is actually spelled?

What evidence do we have that stars are forming right now? Molecular clouds? why do we know that molecular clouds are where stars form? any other lines of evidence? i know this is a big topic so a few reasons or a good link would be a good start for me to understand this big topic thanks

This is another round of excellent pictures submited by several PF members. 1. larkspur http://home.comcast.net/~larkspur2020/Milkyway.jpg 2. DarkEternal http://web.mit.edu/deternal/Public/Chile/LCO1PF.jpg 3. neutrino 4. turbo-1...

[SIZE="5"]When You Wish Upon A Star The Space Shuttle is back in space. To mark that occasion, the photo contest theme this time will be on anything and everything related to NASA, Astronomy, the Heavens, Space Travel/Exploration, etc. You will have a few extra days to submit a photo...

How do we know that a photon coming from a far away star is redshifted? Since we only can measure wavelength here on Earth how do we know that its wavelength was shorter when emited? thanks

How do I go about working out the radius of a star when I have the bolometric flux, the wavelength of the peak flux of its spectrum, and its parallax? I've also calculated the temperature of its photosphere (Wein's law right?). Or is it more to do with the parallax?

Could the process of star formation in a collapsing gas cloud transform the process of virialisation and ultimately promote the formation of a central black hole? Consider the following idealised and oversimplified scenario. Suppose a gas cloud massive enough to generate vast numbers of...

I couldn't pass this one up. I am still laughing. [PLAIN][/URL]

can u help me to explain the role of gravity in the equilibrium of stars in their production of enegry , and an explanation of the role of gravity in the formation of planets. thankssssssss

is Alpha Centauri, the closes star to the solar system?

May the 4th be with you! :redface: :redface: :redface: :redface: :redface: :biggrin: :biggrin: :biggrin: :biggrin: :biggrin:

http://www.spacedaily.com/reports/Evidence_Mounts_For_Companion_Star_To_Our_Sun.html the above article seems to suggest that we are part of a binary star system. I thought (or rather assumed) that astronomers would have done a thorough scan of our neighborhood by now - so why hasn't anyone...

I've been reading articles on star formation and would like to know what the Pre-main-sequence actually stands for. Since more or less each stage of the formation of a star have names what type of star are inclusive in the PMS? How can you point out a PMS star from a main sequence star?

I herd of a theory about red or brown dwarf that is a companion star with the Sun.I looked on http://en.wikipedia.org/wiki/Nemesis_%28star%29" it doesn't too much about it. Dose anyone know if there's been any stars that could possible Nemesis or if there's any evidnce of it's existence.

Is there anything in the observable universe that weighs more? 1 teaspoon = billion tons