APOD: LDN 1471: A Windblown Star Cavity (2020 May 06)

[APOD Robot]

LDN 1471: A Windblown Star Cavity

Explanation: What is the cause of this unusual parabolic structure? This illuminated cavity, known as LDN 1471, was created by a newly forming star, seen as the bright source at the peak of the parabola. This protostar is experiencing a stellar outflow which is then interacting with the surrounding material in the Perseus Molecular Cloud, causing it to brighten. We see only one side of the cavity -- the other side is hidden by dark dust. The parabolic shape is caused by the widening of the stellar-wind blown cavity over time. Two additional structures can also be seen either side of the protostar, these are known as Herbig-Haro objects, again caused by the interaction of the outflow with the surrounding material. What causes the striations on the cavity walls, though, remains unknown. The featured image was taken by NASA and ESA’s Hubble Space Telescope after an original detection by the Spitzer Space Telescope.

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[JohnD]

This looks at first as if the star itself has a high velocity through the Perseus Cloud, leading to its outflow forming a shockwave. But we are told that half of the formation is obscured by a dust cloud, so is it in fact comparable to an object such as the Ant Nebula? (Menzel3) https://apod.nasa.gov/apod/ap150426.html
JOhn

[orin stepanek]

It looks like the protostar is almost hatched! I also noticed the
beautiful spiral in the upper right corner! hard to see in this small
view!

[neufer]

• More like a catenary than a parabola.

Antoni Gaudí's catenary model at Casa Milà

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<<In physics and geometry, a catenary is the curve that an idealized hanging chain or cable assumes under its own weight when supported only at its ends. The catenary curve has a U-like shape, superficially similar in appearance to a parabolic arch, but it is not a parabola. The curve appears in the design of certain types of arches and as a cross section of the catenoid—the shape assumed by a soap film bounded by two parallel circular rings. The catenary is also called the alysoid, chainette, or, particularly in the materials sciences, funicular.

Mathematically, the catenary curve is the graph of the hyperbolic cosine function. The surface of revolution of the catenary curve, the catenoid, is a minimal surface, specifically a minimal surface of revolution. A hanging chain will assume a shape of least potential energy which is a catenary. The mathematical properties of the catenary curve were first studied by Robert Hooke in the 1670s, and its equation was derived by Leibniz, Huygens and Johann Bernoulli in 1691. Catenaries and related curves are used in architecture and engineering, in the design of bridges and arches, so that forces do not result in bending moments.>>

[Leon1949Green]

So very intriguing, and the discussions so far. It made me wonder it this might have been the way of our star in its birth, and had something to do with the clearing out of the cavity that we are in. Anyone?

[FUN in partICULAR]

• More like a catenary than a parabola.

Antoni Gaudí's catenary model at Casa Milà

---

<<In physics and geometry, a catenary is the curve that an idealized hanging chain or cable assumes under its own weight when supported only at its ends. The catenary curve has a U-like shape, superficially similar in appearance to a parabolic arch, but it is not a parabola. The curve appears in the design of certain types of arches and as a cross section of the catenoid—the shape assumed by a soap film bounded by two parallel circular rings. The catenary is also called the alysoid, chainette, or, particularly in the materials sciences, funicular.

Mathematically, the catenary curve is the graph of the hyperbolic cosine function. The surface of revolution of the catenary curve, the catenoid, is a minimal surface, specifically a minimal surface of revolution. A hanging chain will assume a shape of least potential energy which is a catenary. The mathematical properties of the catenary curve were first studied by Robert Hooke in the 1670s, and its equation was derived by Leibniz, Huygens and Johann Bernoulli in 1691. Catenaries and related curves are used in architecture and engineering, in the design of bridges and arches, so that forces do not result in bending moments.>>

A Funicular

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[neufer]

Click to play embedded YouTube video.

funicular (adj.) 1660s, from funicle "a small cord" (1660s), from Latin funiculus "a slender rope," diminutive of funis "a cord, rope," of unknown etymology. De Vaan suggests it is a derivative of the root of filum. A funicular railway (1874) is one worked by a cable from a stationary engine.

[Ann]

So very intriguing, and the discussions so far. It made me wonder it this might have been the way of our star in its birth, and had something to do with the clearing out of the cavity that we are in. Anyone?

I usually chime in, but the tantrums of baby stars are not my forte... Anyway. The Sun was probably born in a rather rich cluster which contained at least one star massive enough to go supernova. Hey, our Sun had an adventurous youth.

I want to point out that most stars are less massive than the Sun, so chances are that LDN 1471 is less massive than the Sun, in which case the Sun's babyhood was probably a little different from this one. Not too different, though.

But the bubble we are in has nothing to do with the Sun's birth. The Sun was born some five billion years ago, and it completes one orbit around the galaxy in about 250 million years, so if you're in the mood, you can figure out how many turns the Sun has made around the center of the Galaxy. I find it unlikely that even the supernova remnant of the Sun's now hopelessly scattered birth cluster remains after 5 billion years, and it is absolutely certain that nothing remains of the little bubble that our Sun carved out during its birth pangs.

Not that we have to slightest idea where to look for the site of our Sun's birth. But the chances that it just happens to be where we happen to be just now.... Naaaah.

Ann

[Leon1949Green]

Thanks, Ann!

[Chris Peterson]

Not that we have to slightest idea where to look for the site of our Sun's birth. But the chances that it just happens to be where we happen to be just now.... Naaaah.

I believe that there have been a few papers published that identified possible stars that might have formed in the same nursery as the Sun. Because everything around us is orbiting the galaxy together. So absent some kind of perturbation, much of the stuff around us now has been around us for billions of years. Gas, as in the local bubble? No, that has a short lifetime in any one location, because it dissipates or is blown away by very small forces. But stars? That's a different matter. Most of the stars that formed when the Sun did are probably still nearby.

[Fred the Cat]

Finding our nearest relatives seems quite anthropologic until you meet one.

It would been nice if you find a reason to bond.

[neufer]

Click to play embedded YouTube video.

I believe that there have been a few papers published that identified possible stars that might have formed in the same nursery as the Sun. Because everything around us is orbiting the galaxy together. Most of the stars that formed when the Sun did are probably still nearby.

Finding our nearest relatives seems quite anthropologic until you meet one.

https://en.wikipedia.org/wiki/HD_162826
https://en.wikipedia.org/wiki/HD_186302

[Rick B.]

Can I say it is reminiscent of the space ex launch that deployed satellites and produced a very odd shaped but also symmetrical plume?