Starship Asterisk*

MarkBour wrote:
How has an estimate of the age of the outer filaments been made?

• 1) A Doppler measurement of the current expansion rate in combination
  
  2) with a simple physical model of the average expansion rate over time.

BDanielMayfield wrote:
The strangest part of this outer halo is near the right edge. There's a piece that resembles the cone nebula or a comet, but its orientation is odd, like it's moving at nearly a right angle to the stellar wind. How might this be explained?

neufer wrote:Perhaps it used to be one of the "wing tips" of the "very central region."

BDanielMayfield wrote:The strangest part of this outer halo is near the right edge. There's a piece that resembles the cone nebula or a comet, but its orientation is odd, like it's moving at nearly a right angle to the stellar wind. How might this be explained?

neufer wrote:"wing tips"

Chris Peterson wrote:

BDanielMayfield wrote:The strangest part of this outer halo is near the right edge. There's a piece that resembles the cone nebula or a comet, but its orientation is odd, like it's moving at nearly a right angle to the stellar wind. How might this be explained?

I'd say it's the pattern recognition system of your brain coming to a false conclusion. You're not looking at something moving perpendicular to the radial flow, you're looking at a shock front moving outwards with everything else. Because it's denser at one end than the other, your brain is screaming "comet". Of course, even comets are seldom actually moving in the direction our minds try to convince us they are.

BDanielMayfield wrote:I haven't come to any conclusion, false or otherwise, and I realize that there is no way this could be a comet for several reasons.

Actually, what this "object" reminds me of most is a particle leaving a vapor trail in a cloud chamber, so I would respectfully ask, is it possible that there could be an orbiting or just passing object like a gas giant to red dwarf star mass inside the dense end that is leaving a trail-like wake in the ejecta it is passing through?

meadowlark7 wrote:As the sun revolves around the Milky Way in a span of several hundred million years, will it likely pass through dust clouds or star forming regions and perhaps pick up mass that will defer its ultimate demise?

Chris Peterson wrote:

meadowlark7 wrote:
As the sun revolves around the Milky Way in a span of several hundred million years, will it likely pass through dust clouds or star forming regions and perhaps pick up mass that will defer its ultimate demise?

The Solar System will certainly pass through dust, and possibly some active star forming regions. Neither will have any effect on it. The densest gas and dust regions are still hard vacuums, and even the paltry wind from our stable little star will blow away anything long before it could be captured and add any mass.

• Except, perhaps, for some ENAMAss:

http://en.wikipedia.org/wiki/IBEX wrote:
<<IBEX is collecting Energetic neutral atom (ENA) emissions that are traveling through the solar system to Earth that cannot be measured by conventional telescopes. These ENAs are created on the boundary of our Solar System by the interactions between solar wind particles and interstellar medium particles.

On the average IBEX-Hi detects about 500 particles a day, and IBEX-Low, less than 100. By 2012, over 100 scientific papers related to IBEX were published, described by the PI as "an incredible scientific harvest".>>

BDanielMayfield wrote:One other thing though. I wonder what might account for the brightest part of the halo on the right side?

geckzilla wrote:

BDanielMayfield wrote:One other thing though. I wonder what might account for the brightest part of the halo on the right side?

It's a mess blowing off your outer layers, especially if you've got another star orbiting nearby. You should try to think of its three dimensional structure. It's too easy to forget that we are viewing a spherical structure when they look so much like they are flat disks and we just happen to view them face on.

BDanielMayfield wrote:I was thinking three and even four dimensionally, and I do think it has another star nearby. I was thinking that there might even be a star somewhere close to or embedded inside the brighter part of the halo on the right side, lighting it up. Something has to be making that part of the halo brighter. What do you think?

Chris Peterson wrote:

BDanielMayfield wrote:I was thinking three and even four dimensionally, and I do think it has another star nearby. I was thinking that there might even be a star somewhere close to or embedded inside the brighter part of the halo on the right side, lighting it up. Something has to be making that part of the halo brighter. What do you think?

Yes, but keep in mind that the halo is barely brighter than the sky background- orders of magnitude dimmer than the central planetary nebula (composited from an HST image). The halo is made from narrowband images, which dramatically reduce the intensity of any stars in the field. Bottom line: it's really difficult to make any solid assessments about how bright anything is here. But most likely, virtually all the light of the halo is emitted, not reflected. The bright area to the right is larger than other bright spots, but not brighter. I think it's probably just another region that's shocked, or is just a little denser and therefore brighter from the stimulation of the central star.

BDanielMayfield wrote:

neufer wrote:
Perhaps it used to be one of the "wing tips" of the "very central region."

But this outer feature is asymmetrical with respect to the central star. I could go along with your suggestion if there was something like it on the left, but there isn't.

Could this comet like object be caused by something in orbit of the central star interacting with its ejecta?

http://en.wikipedia.org/wiki/Cat%27s_Eye_Nebula#Kinematics_and_morphology wrote:
<<The Cat's Eye Nebula is structurally a very complex nebula, and the mechanism or mechanisms that have given rise to its complicated morphology are not well understood. It is suspected that the central star of the nebula may be a binary star. The existence of an accretion disk caused by mass transfer between the two components of the system may give rise to polar jets, which would interact with previously ejected material. Over time, the direction of the polar jets would vary due to precession.>>

Ron-Astro Pharmacist wrote:I think I've asked this before but should the original star had gas giant planets within close proximity (or far) from the star sloughing off matter – could their remnants be noticeable or dectected amongst the star material being ejected?