Starship Asterisk*

I understood that planetary rings were a mystery since they should "evaporate" or dissipate by collisions or fall into the parent planet over only millions of years. Then I read recently, there is some thinking due to Cassini probe findings that the rings may be as old as the solar system...

The claim is made that protostars with masses more than 0.08 solar masses will begin to reach temperature high enough for nuclear fusion of hydrogen. So when a sufficient core size develops, a T Tauri wind or strong stellar wind is generated to repel the infall of more material thereby limiting the ...

When thermonuclear fusion begins in the core of a new star, a strong stellar wind is produced to prevent the infall of any new mass - so the theory goes. What is the comparison in strength between this T Tauri wind and the current solar winds ? For how many AU's was this wind effective in evacuating...

How is the rotational velocity of a larger celestial body affected if a smaller body strikes it on its equator but off-center longitudinally by "x" degrees ? Consider that the collision is almost totally inelastic and most of the smaller body is absorbed. Angular momentum is conserved in ...

This article may answer my question. Thanks.

Doug Ettinger

How is the rotational velocity of a larger celestial body affected if a smaller body strikes it on its equator but off-center longitudinally by "x" degrees ?
Consider that the collision is almost totally inelastic and most of the smaller body is absorbed.

Doug Ettinger
Pittsburgh, PA

I originally thought most of the infalling mass that could create overspin of the newly formed Sun was lost through polar jets of materials. Then I read that the HH objects resulting from these polar jets are only 1 to 20 Earth masses. So how does the angular momentum of the material falling inward ...

There are numerous kinds of variable stars. It is not clear to me what the basic correlation or difference is between Cepheid variables and other variables such as T Tauri and Herbig Ae/Be variables. Are Cepheids just a class of T Tauri with better known variable luminosities and pulsation periods ?...

I understood that planetary rings were a mystery since they should "evaporate" or dissipate by collisions or fall into the parent planet over only millions of years. Then I read recently, there is some thinking due to Cassini probe findings that the rings may be as old as the solar system....

You did not appreciate my analogy of why horizontal disks form in the Earth's atmosphere and for the same reasons cannot form in a GMC. Other factors are needed.

Doug Ettinger

Thank you for your very thoughtful reply. I very much like your very plausible ejection of one or more Jupiter mass objects. I am very impressed with the quickness of the angler pulling this answer out of his fishnet. It probably means that there are a lot of ejected Jupiters and assorted rocks and ...

Podcast: Rotation Universe Today - 23 April 2010 Everything in the Universe is spinning. In fact, without this rotation, life on Earth wouldn't exist. We need the conservation of angular momentum to flatten out galaxies and solar systems, to make planets possible. Let's find out about the physics i...

Can the rotational velocities of nearby single stars be measured using the Doppler affect if its alignment with Earth is appropriate? Of course, I know neutron stars or pulsar rotations are measured. Interferometric techniques are probably good enough now that a handful of stars might have their ro...

Please refer me to Wikipedia for some of your answers when it makes sense. I do not want to waste your valuable time when I can easily find it in Wikipedia.

Doug Ettinger

The Sun's equatorial plane is inclined 5.6 degrees to the invariable plane. Are there any hypothetical reasons for this occurrence inside or outside the nebular hypothesis ? Just my suggestion- I haven't read anything about the matter. Once the nebula condenses sufficiently that fluid dynamics stop...

It should be noted that Saturn and all the gas giants maintain very flat equatorial ring systems primarily because of a strong quadrupole gravitational force field. I don't believe that is true. The primary reason that rotating systems become very flat is because of inelastic collisions between par...

You are absolutely right. I am more and more amazed at all the current information that can be found in Wikipedia. Who feeds this excellent information to the free encyclopedia?

Doug Ettinger

The Sun's equatorial plane is inclined 5.6 degrees to the invariable plane. Are there any hypothetical reasons for this occurrence inside or outside the nebular hypothesis ?

Doug Ettinger
Pittsburgh, PA

Can the rotational velocities of nearby single stars be measured using the Doppler affect if its alignment with Earth is appropriate? Of course, I know neutron stars or pulsar rotations are measured.

Doug Ettinger
Pittsburgh, PA

In a science article the Earth's Lagrange points were discussed. I quote the article - "the five orbital positions where objects can be stationary relative to the Earth and the Sun." I presume that stationary relative to the Sun means orbital distance only. What theory or equation(s) expla...

OK. What is a quadrupole gravitational force field ? Saturn spins so fast that it takes the shape of an oblate spheroid. This shape distorts the radial gravitational field in a very specific way much like as the four fold EM force fields below: http://www.pascal-man.com/tensor-quadrupole-interactio...

Is a quadrupole a May pole with four ropes? I am just kidding, Neufer. OK. What is a quadrupole gravitational force field ?

Doug Ettinger
Pittsburgh, PA

The majority of asteroids and their brethren, the meteorites, could well be collisional artifacts from the early solar system as well as the mid to late solar system and are not items captured from interstellar space. But the Kuiper Belt planetoids, perhaps like Pluto and Triton, certainly have roc...

Then I am not sure what the new revelation is. Any comet has its surface eroded by the solar winds as it orbits the sun.

doug ettinger

The majority of asteroids and their brethren, the meteorites, could well be collisional artifacts from the early solar system as well as the mid to late solar system and are not items captured from interstellar space. But the Kuiper Belt planetoids, perhaps like Pluto and Triton, certainly have roc...