Post by Brad GuthPost by Brad GuthThere are many well known long-period companion stars as extended
binaries, trinaries and greater multiples as complex star systems as
having their interrelated tidal associations that exceed 100,000 year
cycles of proper motions within the greater 225 million year galactic
cycle of proper motion. There are also galactic companion or rogue
molecular/nebula clouds of significant mass and creating those
progenitor stars that come and go depending on their individual size
and mass.
“Many visual binaries have long orbital periods of several centuries”
“The orbital period can e.g. be a few days (components of Beta Lyrae),
but also hundreds of thousands of years (Proxima Centauri around Alpha
Centauri AB),”
The ESA stellar Hipparcos survey of proper motions that’s seldom
utilized to its potential, shows us quite a lot about our pocket realm
of the galactic cycle, in that essentially everything remains in orbit
around something, including multiple long-period star systems and
their tidal influence on others (including our solar system) as we all
get to stick with trekking about our galactic center that isn’t about
to set any of us free.
“Tales of a thousand and one nights: Past and future of the Milky Way”
"The Geneva-Copenhagen survey of the Solar neighbourhood",
by B. Nordström et al.http://www.aanda.org/index.php?option=com_content&view=article&id=71%...
“Most of the stars are located within about 500 light-years from the
Earth and were already observed by the ESA satellite Hipparcos to
measure their precise distances and motions in the plane of the sky.
But a key piece was missing in our knowledge of their space motions in
the Galaxy: The radial velocities [1] of the stars were still not
measured, so only their 2D motions were known. The team of astronomers
has now filled this gap: For the first time, we now know the 3D space
motion of a complete sample of typical stars in the solar
neighbourhood. From their space motions, the team was able to compute
the positions of these stars at different points in the Milky Way's
history. For example, the movie below shows the motions of the
observed stars in their latest orbit around the Galactic Center.”
Plus there’s always loads of other mostly public funded research data
to mine our way through or cheery-pick from.
Galactic Spiral Structure / SpiralStructure.book / SpiralStructure.pdf
“After some time studying the velocity distributions for local stars
we have concluded that the observed stellar streams reflect the spiral
structure of the Milky Way. We have presented a straightforward model
of equiangular spiral arms constructed from elliptical orbits aligned
at a focus. This model applies in coordinates rotating at the spiral
pattern speed, which is equal to the mean rate of orbital precession.
We have shown by qualitative argument and by numerical simulation
describing perturbations to elliptical orbits, that, for a range of
arm densities, spiral structure is dynamically stable, up to
destruction by a bar and/or a ring. We have shown that, for a two-
armed equiangular spiral with pitch angle set to match the
distribution of neutral hydrogen, the observed eccentricity and
velocity distributions are a good fit to the predictions of the model
after taking expected perturbations into account. We have accounted
for all stellar streams in the observed local velocity distributions.
We find that the Sun follows a very typical orbit aligned to the Orion
arm, which is a major spiral arm containing Perseus and Sagittarius
sectors. We have calculated that its current eccentricity is 0.138.
This is a little higher than the modal value, 0.11, for stars in the
arm, giving a typical orbital period of about 300 Myrs – longer than
usually estimated because of the greater eccentricity. We have seen
how spiral structure can evolve to form the rings and bars found in
many galaxies, and that gas motions determine that flocculent galaxies
evolve toward bisymmetric spirals. We have found that the Milky Way
evolved into this form about 9 Gyrs ago.
“It is perhaps worth remarking that the model has made genuine
predictions, and not merely been retrodictively fitted to data. Having
made a prediction of a galactic structure, we searched images to find
examples of the configuration. The interlinked ring structure of
figure 18 was recognised by the astronomer (E.A.) among the authors,
but it was not known to the mathematician (C.F.), who produced the
figure from the numerical solution of perturbed orbits. The same was
true of the prediction that young stars are to be found on the outside
of spiral arms. Nor did we know of galaxies where the spiral arms are
separate from the ring. We have not made any predictions of galactic
structures for which we were unable to find examples.”
What this all means to me is that a lot of complex stellar tidal
issues manage to keep many significant items closely enough associated
with one another, and yet with long-period orbital treks that can’t be
ignored if you want to understand and better appreciate what sorts of
local stellar motions have affected our solar system. The whereabouts
of their progenitor molecular/nebula worthy clouds and their
subsequent demise or disbursements of all that terrific mass also
can’t be excluded, especially when such nearby clouds form or merge as
3e37 kg or greater mass and should stick around for a few million
years as they crank out impressive stars like those of Sirius w/
planets, and subsequently heating up their surrounding molecular/
nebular cloud that gets forced out by those terrific solar winds that
almost never let up.
~ BG
Escape from Sirius is perhaps a little easier said than accomplished,
especially when it was worth so much extra mass (<1.9e31 kg for
Sirius[B] and <2.6e31 for the whole package deal) to begin with, and
perhaps only a million fold worse yet as a molecular/nebula cloud
along with its progenitor stars, further compounded by us having been
moving towards that terrific mass at 7.6 km/sec, rather than away (not
that there’s any objective science telling us exactly where those
Sirius progenitor stars and their molecular/nebula cloud were to begin
with, as most likely from a molecular/nebula cloud derived from a
galactic merger). Perhaps the theory of a similar supernova event
that gave our sun its start is what also transpired on behalf of
boosting those Sirius progenitor stars to life.
Lagrange Point Finder
http://www.orbitsimulator.com/formulas/LagrangePointFinder.html
Using 8.136e16 meters, 7e30 kg and 2e30 kg
The L4/L5 velocity is just .086 km/sec.
Perhaps the L2 of 0.128 km/sec is close to escape velocity.
At 0.1 ly (9.46e14 m) gives the L2 velocity of 1.19 km/sec
http://www.calctool.org/CALC/phys/astronomy/escape_velocity
at 8.6 ly the escape velocity from 7e30 kg = 0.107167 km/sec
at .1 ly (9.46e11 km) the escape velocity from Sirius only climbs to
1 km/sec, but neither of these are taking into account the added
gravity pull of our solar system or any barycenter considerations.
Thus far the required escape velocity from Sirius doesn’t seem so
great, so why exactly are we headed back towards that sucker at 7.6 km/
sec?
Even at a spread of 1000 ly and 2.5e37 kg, we’re looking at an exit/
escape velocity of 18.8 km/sec required in order that our solar system
to avoid that amount of molecular/nebula gravitational tidal radii
grip. Problem is, at least as of lately and for as long as anyone can
figure, it seems we’ve been headed the wrong way.
If we always had a purely linear -7.6 km/sec closing velocity to deal
with, and 250 million years of that constant velocity without any
radial trajectory deviations, this only adds up to 6334 ly plus our
existing 8.6 ly. = 6343 ly, and at that separation would require 7.46
km/sec escape velocity (escape meaning as per our moving away from and
otherwise not as headed towards that original molecular/nebula cloud
of 2.5e37 kg).
Obviously as we close in on the existing depleted mass of the Sirius
star system(7e30 kg), at some point the closing velocity of our
elliptical path should increase, just like those elliptical treks of
Sedna and any other Oort cloud items that stick with us, and otherwise
like many comets do not maintain a constant velocity throughout their
extended radial elliptic trajectory. Sedna that’s currently at 89 AU
is likely moving a few percent faster than at 900+ AU, suggesting that
our negative radial trajectory velocity with Sirius may also be on the
increase.
http://www.thelivingmoon.com/43ancients/02files/Sedna_01.html
Where’s the fully 3D interactive three body orbital simulation of
stellar proper motions that’ll work this rogue analogy of Sirius and
our solar system from the full elliptical trajectory and barycenter
point of view?
Brad Guth, Brad_Guth, Brad.Guth, BradGuth, BG / “Guth Usenet”
There are actually many well known long-period companion stars as
extended binaries, trinaries and greater multiples as complex star
systems as having their interrelated tidal associations that exceed
100,000 year cycles of proper motions within the greater 225 million
year galactic cycle of its spiral motion. There are also galactic
companion or rogue molecular/nebula clouds of significant mass and
creating those progenitor stars that come and go depending on their
individual size and mass.
“Many visual binaries have long orbital periods of several centuries”
“The orbital period can e.g. be a few days (components of Beta Lyrae),
but also hundreds of thousands of years (Proxima Centauri around Alpha
Centauri AB),”
The ESA stellar Hipparcos survey of proper motions that’s seldom
utilized to its potential, shows us quite a lot about our pocket realm
of the galactic cycle, in that essentially everything remains in orbit
around something, including multiple long-period star systems and
their tidal influence on others (including our solar system) as we all
get to stick with trekking about our galactic center that isn’t about
to set any of us free.
“Tales of a thousand and one nights: Past and future of the Milky Way”
"The Geneva-Copenhagen survey of the Solar neighbourhood",
by B. Nordström et al.
http://www.aanda.org/index.php?option=com_content&view=article&id=71%3Atales-of-a-thousand-and-one-nights-6-april-2004&catid=79%3A2004-press-releases&Itemid=276&lang=en_GB.utf8%2C+en_GB.UT
“Most of the stars are located within about 500 light-years from the
Earth and were already observed by the ESA satellite Hipparcos to
measure their precise distances and motions in the plane of the sky.
But a key piece was missing in our knowledge of their space motions in
the Galaxy: The radial velocities [1] of the stars were still not
measured, so only their 2D motions were known. The team of astronomers
has now filled this gap: For the first time, we now know the 3D space
motion of a complete sample of typical stars in the solar
neighbourhood. From their space motions, the team was able to compute
the positions of these stars at different points in the Milky Way's
history. For example, the movie below shows the motions of the
observed stars in their latest orbit around the Galactic Center.”
Plus there’s always loads of other mostly public funded research data
to mine our way through or cheery-pick from.
Galactic Spiral Structure / SpiralStructure.book / SpiralStructure.pdf
“After some time studying the velocity distributions for local stars
we have concluded that the observed stellar streams reflect the spiral
structure of the Milky Way. We have presented a straightforward model
of equiangular spiral arms constructed from elliptical orbits aligned
at a focus. This model applies in coordinates rotating at the spiral
pattern speed, which is equal to the mean rate of orbital precession.
We have shown by qualitative argument and by numerical simulation
describing perturbations to elliptical orbits, that, for a range of
arm densities, spiral structure is dynamically stable, up to
destruction by a bar and/or a ring. We have shown that, for a two-
armed equiangular spiral with pitch angle set to match the
distribution of neutral hydrogen, the observed eccentricity and
velocity distributions are a good fit to the predictions of the model
after taking expected perturbations into account. We have accounted
for all stellar streams in the observed local velocity distributions.
We find that the Sun follows a very typical orbit aligned to the Orion
arm, which is a major spiral arm containing Perseus and Sagittarius
sectors. We have calculated that its current eccentricity is 0.138.
This is a little higher than the modal value, 0.11, for stars in the
arm, giving a typical orbital period of about 300 Myrs – longer than
usually estimated because of the greater eccentricity. We have seen
how spiral structure can evolve to form the rings and bars found in
many galaxies, and that gas motions determine that flocculent galaxies
evolve toward bisymmetric spirals. We have found that the Milky Way
evolved into this form about 9 Gyrs ago.
“It is perhaps worth remarking that the model has made genuine
predictions, and not merely been retrodictively fitted to data. Having
made a prediction of a galactic structure, we searched images to find
examples of the configuration. The interlinked ring structure of
figure 18 was recognised by the astronomer (E.A.) among the authors,
but it was not known to the mathematician (C.F.), who produced the
figure from the numerical solution of perturbed orbits. The same was
true of the prediction that young stars are to be found on the outside
of spiral arms. Nor did we know of galaxies where the spiral arms are
separate from the ring. We have not made any predictions of galactic
structures for which we were unable to find examples.”
What this all means to me is that a lot of complex stellar tidal
issues manage to keep many significant items closely enough associated
with one another, and yet with long-period orbital treks that can’t be
ignored if you want to understand and better appreciate what sorts of
local stellar motions have affected our solar system. The whereabouts
of their progenitor molecular/nebula worthy clouds and their
subsequent demise or disbursements of all that terrific mass also
can’t be excluded, especially when such nearby clouds form or merge as
3e37 kg or greater mass and should stick around for a few million
years as they crank out impressive stars like those of Sirius w/
planets, and subsequently heating up their surrounding molecular/
nebular cloud that gets forced out by those terrific solar winds that
almost never let up.
~ BG
