Hubble Finds Huge System of Dusty Material Enveloping HR 4796A

[bystander]

Hubble Finds Huge System of Dusty Material Enveloping the Young Star HR 4796A
NASA | STScI | HubbleSite | 2018 Mar 06

Credits: NASA/ESA/G. Schneider (Univ. of Arizona)

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Astronomers have used NASA's Hubble Space Telescope to uncover a vast, complex dust structure, about 150 billion miles across, enveloping the young star HR 4796A. A bright, narrow, inner ring of dust is already known to encircle the star and may have been corralled by the gravitational pull of an unseen giant planet. This newly discovered huge structure around the system may have implications for what this yet-unseen planetary system looks like around the 8-million-year-old star, which is in its formative years of planet construction.

The debris field of very fine dust was likely created from collisions among developing infant planets near the star, evidenced by a bright ring of dusty debris seen 7 billion miles from the star. The pressure of starlight from the star, which is 23 times more luminous than the Sun, then expelled the dust far into space.

But the dynamics don't stop there. The puffy outer dust structure is like a donut-shaped inner tube that got hit by a truck. It is much more extended in one direction than in the other and so looks squashed on one side even after accounting for its inclined projection on the sky. This may be due to the motion of the host star plowing through the interstellar medium, like the bow wave from a boat crossing a lake. Or it may be influenced by a tidal tug from the star's red dwarf binary companion (HR 4796B), located at least 54 billion miles from the primary star. ...

The HR 4796A Debris System: Discovery of Extensive Exo-ring Dust Material - Glenn Schneider et al

• Astronomical Journal 155(2):77 (2018 Feb) DOI: 10.3847/1538-3881/aaa3f3
  arXiv.org > astro-ph > arXiv:1712.08599 > 22 Dec 2017

[Ann]

This is yet another star of spectral class A that turns out to have a huge dust system surrounding it.

Of course, this one is more remarkable than most, because, as the caption said, its "puffy outer dust structure is like a donut-shaped inner tube that got hit by a truck".

Fascinating! And personally I must wonder what happens to all this dusty stuff surrounding A-class stars when the stars keep blasting their dust with A-class star levels of ultraviolet radiation. Does the dust have time to form planets? I guess it does, because Fomalhaut has a planet.

Ann

[neufer]

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This is yet another star of spectral class A that turns out to have a huge dust system surrounding it. Of course, this one is more remarkable than most, because, as the caption said, its "puffy outer dust structure is like a donut-shaped inner tube that got hit by a truck".

Fascinating! And personally I must wonder what happens to all this dusty stuff surrounding A-class stars when the stars keep blasting their dust with A-class star levels of ultraviolet radiation. Does the dust have time to form planets? I guess it does, because Fomalhaut has a planet.

[Ann]

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This is yet another star of spectral class A that turns out to have a huge dust system surrounding it. Of course, this one is more remarkable than most, because, as the caption said, its "puffy outer dust structure is like a donut-shaped inner tube that got hit by a truck".

Fascinating! And personally I must wonder what happens to all this dusty stuff surrounding A-class stars when the stars keep blasting their dust with A-class star levels of ultraviolet radiation. Does the dust have time to form planets? I guess it does, because Fomalhaut has a planet.

Watch out, Pig-Pen, or you may form your own planetary system!

Ann