More than 90 percent of objects found in the vast outer-solar system reservoir may have been born around other stars
in [Physics]
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From: Sam Wormley on 13 Jun 2010 15:16 On 6/13/10 10:23 AM, Brad Guth wrote: > btw, a star doesn't get to being a red supergiant without first having > lost at least a third of its original mass. > > ~ BG Um... I think there is plenty of evidence that stars lose substantial mass as part of their violent red giant phase. But so much depends on the main sequence mass of the star, for that dictates what nuclear processes will follow after main sequence life. For stars to produce White Dwarfs, Main Sequence mass ranges from 0.8-8 solar masses. With core masses between 0.6 and 1.44 solar masses are destined to become white dwarfs. This was the case for Sirius B and will be so for Sirius A. Brad, I suggest you do a bit of self education concerning stellar evolution. The are many excellent textbooks and other sources of this information.
From: Brad Guth on 13 Jun 2010 15:37 On Jun 13, 9:02 am, "Greg Neill" <gneil...(a)MOVEsympatico.ca> wrote: > Brad Guth wrote: > > On Jun 13, 6:11 am, "Greg Neill" <gneil...(a)MOVEsympatico.ca> wrote: > >> Brad Guth wrote: > >>> On Jun 12, 6:05 pm, "Greg Neill" <gneil...(a)MOVEsympatico.ca> wrote: > >>>> You are mistaken in your interpretation. With a speed of > >>>> about 18.2 km/sec (combining the Sirius system's radial and > >>>> proper motions), and given the mass of the system as about > >>>> 3 solar masses, the total mechanical energy of the Sun-Sirius > >>>> system is about 1.67 x 10^8 J/kg, a positive value. Thus > >>>> the Sirius system and our solar system are not gravitationally > >>>> bound; their mutual trajectory will be open and hyperbolic. > >>> I don't agree with that subjective interpretation of yours. > > >> Subjective? The current mass of the Sirius system is > >> known from simple Newtonian mechanics. The proper motion > >> and radial velocity are measured. The conclusion is > >> drawn from the given facts via standard Newtonian orbital > >> mechanics. > > >> For any two-body gravitationally interacting bodies, > >> the total specific mechanical energy is given by: > > >> E = v^2/2 - u/r > > >> where: > >> v is the velocity > >> u is the gravitational parameter for the system: G*(M + m) > >> M and m are the masses of the bodies > >> G is Newton's gravitational constant > > >> All of the above are known values for the system under > >> consideration. > > >> There are two cases of interest for E: > > >> E < 0 : The system is gravitationally bound and will > >> exhibit a circular or elliptical orbit, or if the > >> proper motion is zero, a straight-line collision. > > >> E >= 0: The system is unbound and will exhibit parabolic > >> (E = 0) or hyperbolic trajectories, or if the proper > >> motion is zero, a straight-line collision if the > >> red-shift if negative, or if the red-shift is > >> positive, proceeding away in a straight line > >> indefinitely. > > >> So where are *your* objective facts and what are their > >> accredited sources? > > > I've been sharing those for years. Where have you been for the past > > decade? > > I've been looking at empirically obtained facts, not your > imagination generated mental farts. > > > > > Everything I have to interpret with, you have (unless you've > > intentionally blocked it). > > You make things up as you go along, so no, I don't have > (and don't really want) what you're "sharing". > > > > > You do realize those gravitational strings that keep us associated > > with Sirius are way stronger than what keeps the likes of Sedna > > hanging around. > > > Gravity Force of Attraction (orbital tidal radius) > > http://www.1728.com/gravity.htm > > http://www.wsanford.com/~wsanford/calculators/gravity-calculator.html > > > Sirius and us(our solar system) are very much indeed inseparable, at > > least according to those regular pesky laws of physics pertaining to > > the mainstream accepted notions of Newtonian gravity and orbital > > mechanics, > > No, I just used those "pesky" laws to show that Sirius is > certainy *Not* bound. Where are *your* calculations? > > > that seems way more than sufficient for everything else > > we�re told to accept, and especially if little Sedna can be turned > > around at a tidal radii of 1.459e14 m that�s worth merely 2.975e13 N, > > whereas Sirius at 8.6 light years and worth 1.417e17 N (roughly a 20 > > thousand fold stronger tidal radii grip), > > You are babbling. You don't even know what the terms you > use mean. Tidal radius? Seriously. You also don't seem > to understand that binding involves more than the magnitude > of the forces to determine whether something is gravitationally > bound. Momentum matters, both angular and linear. Ever hear > of the concept of escape velocity? > > At the distance of Sirius the escape velocity from our solar > system is (using u = G*(M_Sun + M_Sirius) ): > > u = 5.31 x 10^20 m^3/s^2 > r = 8.136 x 10^16 m > > v_esc = sqrt(2*u/r) > > = 0.11 km/sec > > Since the Sirius system is travelling in excess of 18 km/sec > relative to us, it is certainly unbound. > > Now let's take a look at Sedna with a semimajor axis of > 7.866 x 10^13 m and an average orbital speed of 1.04 km/sec. > The escape velocity from the Sun at the distance of Sedna > is 1.84 km/sec, which is of course greater than Sedna's > orbital speed, thus Sedna is gravitationally bound. The > same result will be found by using the Mechanical Energy > method that I showed you previously. > > [snip remainder of flotsam] Why do you have to make everyone else out as the bad guy? (were you molested by a priest or rabbi?) Your politically correct and/or faith-based approved obfuscation and denial of those pesky Newtonian laws of gravity are noted. Where were you when BP needed a whole lot better PR damage control? If not due to gravity and those Newtonian laws, why is 2005-VX3 or most any other elliptical trekking Oort item still with us? Didnt you notice that nifty ratio of 2005-VX3 being 83e6:1 less bound than our solar system is to Sirius? Are you suggesting that long-period elliptical trajectories are either conditional or bogus? Do long-period or deep elliptical treks wear out or vanish over time? You do realize Im working with the tidal radii grip that Sirius has on our solar system, and not the other way around. This would have been most important as of the beginning stellar mass of 12.5, and of course worse yet if youd care to deal with that molecular cloud worth <12.5e6 Ms that managed to produce such massive and vibrant stars. Cant your public funded simulators do any better job, of adding and/ or subtracting mass in order to see what happens over various distances, proper motion trajectories and at different velocities? ~ BG
From: Sam Wormley on 13 Jun 2010 15:49 On 6/13/10 2:37 PM, Brad Guth wrote: > Are you suggesting that long-period elliptical trajectories are either > conditional or bogus? elliptical orbits (0 < eccentricity < 1) are closed orbits. The sun is not in a closed orbit with any other star in our local neighborhood, including Sirius.
From: Brad Guth on 13 Jun 2010 16:35 On Jun 13, 12:49 pm, Sam Wormley <sworml...(a)gmail.com> wrote: > On 6/13/10 2:37 PM, Brad Guth wrote: > > > Are you suggesting that long-period elliptical trajectories are either > > conditional or bogus? > > elliptical orbits (0 < eccentricity < 1) are closed orbits. The sun is > not in a closed orbit with any other star in our local neighborhood, > including Sirius. Everything out there, including our solar system, is in orbit around something, as otherwise what good are black holes. ~ BG
From: Sam Wormley on 13 Jun 2010 16:46
On 6/13/10 3:35 PM, Brad Guth wrote: > On Jun 13, 12:49 pm, Sam Wormley<sworml...(a)gmail.com> wrote: >> On 6/13/10 2:37 PM, Brad Guth wrote: >> >>> Are you suggesting that long-period elliptical trajectories are either >>> conditional or bogus? >> >> elliptical orbits (0< eccentricity< 1) are closed orbits. The sun is >> not in a closed orbit with any other star in our local neighborhood, >> including Sirius. > > Everything out there, including our solar system, is in orbit around > something, as otherwise what good are black holes. > > ~ BG You miss the main point--The sun is not in a closed orbit with any other star in our local neighborhood, including Sirius. |