Starship Asterisk*

Beyond wrote:
Geeze neufer, you keep showing that same picture with the 4 spiked blue star,
but don't indicate where it is in the APOD picture, and i don't see it there.

Ann wrote:

Ann wrote:

APOD Robot wrote: In the Vicinity of the Cone Nebula

Explanation: Even though it points right at S Mon,
details of the origin of the mysterious geometric Cone Nebula, visible on the far left, remain a mystery.

Structures like the Cone Nebula are windblown.

Hot stars like S Mon have tremendous winds,
and star formation, too, causes outflows and jets.

Note that I said that star formation also causes outflows and jets.
The bright infrared source is clearly an example of star formation,
a star that has not, at least, emerged from its natal cocoon.

Beyond wrote:

neufer wrote:

Beyond wrote:

I take it you are referring the star below center,
lower left, that has 6 pink spikes to it?

Yes... the star with 6 pink (infrared) diffraction spikes.

Possibly the star just above the star with 4 blue (visible) diffraction spikes.

I don't see any blue stars with 4 spikes, only 6.
But only one with 6 pink spikes, so that's gotta be the one.

neufer wrote:Possibly the star just above the star with 4 blue (visible) diffraction spikes.

neufer wrote:

[b][color=#0000FF]An infrared Spitzer Space Telescope image of NGC 2264 Credit: SIRTF/NASA/ESA.[/color][/b]

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Ann wrote:
Structures like the Cone Nebula are windblown.

Hot stars like S Mon have tremendous winds,
and star formation, too, causes outflows and jets.

The Cone Nebula is NOT windblown by the distant but
very bright (magnitude 4.66) S Mon/15 Mon in today's APOD.

NOR is the Cone Nebula windblown by the apparently close
& moderately bright (magnitude 7.17) HD 47887 in today's APOD.

Rather, the Cone Nebula is windblown by
the close infrared bright star(s) just beyond HD 47887
( with hexagonal diffraction spikes) only (clearly) visible
at the Cone Nebula apex in this Spitzer Space Telescope image.

Beyond wrote:

I take it you are referring the star below center,
lower left, that has 6 pink spikes to it?

Yes... the star with 6 pink (infrared) diffraction spikes.

Possibly the star just above the star with 4 blue (visible) diffraction spikes.

Ann wrote:
Structures like the Cone Nebula are windblown.

Hot stars like S Mon have tremendous winds,
and star formation, too, causes outflows and jets.

Roland wrote:

zbvhs wrote:
The Cone Nebula looks rather like the wake produced by a blunt body tearing through a tenuous gas at hypersonic speed.

I like this explaination. I've seen a lot of supersonic shock wave imagery and this fits right in there. This would mean the red star at the point if the cone is an intruder from outside the nebula. I wonder if it is on a collison course with any of the stars within the nebula?

http://academic.greensboroday.org/~regesterj/potl/Waves/Doppler/doppler.htm wrote:

[b][color=#0000FF][size=135]A duck that moves faster than the speed of water waves creates a shock. Note how the v-shaped wake looks like a sonic boom.[/size][/color][/b]

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[img3="Schlieren images of various shapes inside a supersonic wind tunnel. These images were taken to study possible shapes of capsules for the Mercury space program. You might think a pointy object would be best for "cutting through the air", but there's a problem: pointy objects come into contact with the shock (like in the top-left picture), which is hot, causing damage to the object. If the object is blunt, however, the shock stands away from the object a little bit, causing less heat to be transferred. That's why the capsules used in the Mercury, Gemini and Apollo programs, and nuclear warheads on ICBMs are cone-shaped and re-enter the Earth's atmosphere blunt end first."]http://academic.greensboroday.org/~rege ... shapes.png[/img3]

zbvhs wrote:The Cone Nebula looks rather like the wake produced by a blunt body tearing through a tenuous gas at hypersonic speed.

Beyond wrote:Wow! I'm in the same category as Art. I hope he doesn't feel too insulted.

geckzilla wrote:

robgendler wrote:
I only come here when I have an APOD (I'm sure you're glad about that) in order to answer any questions about the image. I would have been happy to answer any specific questions people had about the image but there were none. I did see some very good general questions and some very erudite discussion from Ann and others. I also saw "conehead" videos ... I am not a snob... but I guess I just have a hard time with some of the silly posts.

Very few individuals on this forum are qualified to make criticism about an image short of liking it or disliking it so while the conversation often becomes about a particular object and what is interesting about it, sometimes it also deviates into some rather off topic subjects (sometimes really off topic...Art!) but Chris does know a lot about imaging. Beyond and Art are both just goofballs.

• Cymbeline Act 5, Scene 3

• That gave the affront with them.

• But none of 'em can be found.

• The silly buckets on the deck
  That had so long remain’d,
  I dreamt that they were fill’d with dew
  And when I awoke it rain’d.

robgendler wrote:BTW I think there are some good exchanges of information on this forum which are educational. On the other hand some members see someone's dedication and hard work as an opportunity to compete for who can post the wittiest response. I have a sense of humor too but you'll never see this on dedicated CCD forums because those folks understand what goes into an image like this and they are always respectful.

robgendler wrote:Chris...well as soon as I saw your comment above I realized that you have no idea how the image was made.

Any bloating of the stellar cores was simply a result of nonlinear processing....which was required to display the immense dynamic range of this field. A single shot image of this field with this level of detail is simply impossible with today's telescopes and camera technology.

BTW I think there are some good exchanges of information on this forum which are educational. On the other hand some members see someone's dedication and hard work as an opportunity to compete for who can post the wittiest response. I have a sense of humor too but you'll never see this on dedicated CCD forums because those folks understand what goes into an image like this and they are always respectful.