I was saying that it is says there are 26 moons now, is all. I guess you could have said the first 21 moons...but I'm not trying to nitpick, really. :wink:

Edit:
#-o Yeah, I should know that, and wouldn't you know The Tempest is one of my least favorite Shakespearean plays...oh, well, I shouldn't post at work, too many distractrions for my addled brain. ~sigh~ #-o

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Sunset

Die Sonne scheidet hinter dem Gebirge. In alle Täler steigt der Abend nieder
mit seinen Schatten, die voll Kühlung sind.

As Grey ponders...

Which particle is faster reaching us from the core of the Sun, a photon or a neutrino? What is the approximate average time difference?

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

Okay, no peeking for this one, since Googling the answer would be really easy. What's the numerical value of the critical density, cosmologically speaking?

The neutrino is fastest, by about a million years, I think;
but this isn't part of the quiz, right?

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Extreme nitpick;
Ariel is also in the Rape of the Lock
(some strange kind of word-association-football was going on when they named these moons, it seems).

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No, it is not part of the quiz (at least not now).

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

A neutrino, since they don't interact with matter all that much. A photon's random walk out of the central radiative layer and then up to the surface is about 10^6 years, IIRC, which is the time difference.

Grey's question is making me think, but from memory, rho_crit=(8*pi*G)/(3*H_0). Yeah, that looks right. (Oh, and c=1, of course.)

Now I gotta think of a question (heck, two answers = two questions, so...)

One:
What is the range of stellar masses that will produce a neutron star at the end of their life? What is the range of masses of the neutron stars produced?

Two:
What two (or three) numbers determine ("most influence" may be slightly more accurate) the size of the Roche lobes in a binary star system?

Edit: After seeing George's post above, I should eliminate one of the questions above. I don't want to, though ( :P ), so pick one or both. One right answer gets it. But that's only if I'm right with Grey's answer.

not the right answer yet.

A clue, The star can expand by upt 61.xx% of its initial size.

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You've got the right constants, but not quite the right arrangement. If you actually work through the units to try to give a single number, you can probably work out where you've gone wrong (since you won't have units of density here). If you're feeling especially bored, you can work out what that would be in hydrogen atoms per cubic meter...

I'm not really updated on the issue, but I remembered that Phil addressed this:
http://www.badastronomy.com/bitesize...ystem/sun.html

Where did you find that?

What question is active at the moment anyway? There seems to be confusion. I'll try one of Tobin's.

The mass must be above 10 solar masses. The mass of the neutron star may be at least the mass of the sun. If it is above 2-3 solar masses, it collapses further into a black hole.

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Roche Lobes

What three numbers determine the size of the Roche lobes
============
Q = Mass ratio defines the shape and relative size of the Roche lobee

i = Inclination Determine Shape end extend of the shadow

Angular momentum too - *Shrugs* Its early and cant remember

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Nope Dang, already solved :x

I think we have the following:

Unanswered


Anwered but so far unconfirmed:

Practically confirmed: (If the BA sayz so , it must be true )

Maybe we can try to cut down on these before posting new ones :-? :-? :-?

I'll try this one:
Answer: One (1)

Edited to add: And a very good night everyone.

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My hacker skills allowed me to find a hidden section of this board. I'm not sure if I'm allowed to tell...

Above 10 solar masses sounds too high to me. IIRC, it was 3-8 solar masses for the progenitor last time I saw it in a textbook.
But that's close enough to close this question, IMO.

Minbari, mass ratio was 1/2 (or 2/3 for the mass of each component). So, to determine the actual size of the Roche Lobes, what other component of the system do you need. (Ignore angular momentum; I'm going with the standard assumption in a close system that it is tidally locked.) You're very close to this answer in what you've posted about q.

Finally, I'm not going to pursue Grey's question any more tonight. My answer is out there though, so if someone else wants to give it a shot using my attempt, go ahead. (Remember, density is g/cm^3, well, in real sastronomers' units, anyway. )

Arneb, heh heh, Wilhelm Tempel...uh, how appropriate. It's in my "easy" book, too... :wink:

OK, most of these questions you guys are coming up with are too hard for me. I've knocked one off.

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Sunset

Die Sonne scheidet hinter dem Gebirge. In alle Täler steigt der Abend nieder
mit seinen Schatten, die voll Kühlung sind.

Hmm, I'll take a crack at this;

What is the range of masses of the neutron stars produced?
=====================================
The maximum mass of a Neutron star is unknown at this stage but Perhaps in the range of 2 - 3 M and some say 3-5 solar masses.

A typical Neutron is 1.4 Solar Mass.

Observations show >2 that I know of (VX-1)
--


What is the range of stellar masses that will produce a neutron star at the end of their life?
=====================================
considering a neutron star is too dense to form into a white dwarf thus probably forms from a low mass star (like our own) OR A type II Supernova, I would take a wild stab in the dark and say somewhere as low as .08 solar masses and high as hmmmm a few hundred thousand solar masses.

asymptotic giant branch star or AGB

supernova 1987A most probably left behind an extremely dense neutron star.

If the mass of the core is greater than 1.4 times the mass of the sun, the degenerate core consists of neutrons and is known as a neutron star.

These upper limits are in the range of the mass of the largest possible white dwarfs.
White dwarf stars are approximately the size of our planet,

Neutron Stars and Pulsars : Sometimes the core remnant of a low-mass star is too dense to form a white dwarf. In these cases, the coreís stellar collapse forms a neutron star.

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