BBC Focus Magazine

[Shadowwolf]

Imagine if the rings of Saturn suddenly disappeared. Astronomers have witnessed the equivalent around a young sun-like star called TYC 8241 2652. Enormous amounts of dust known to circle the star are unexpectedly nowhere to be found.

"It's like the classic magician's trick: now you see it, now you don't. Only in this case we're talking about enough dust to fill an inner solar system and it really is gone!" said Carl Melis of the University of California, San Diego, who led the new study appearing in the July 5 issue of the journal Nature.

A dusty disk around TYC 8241 2652 was first seen by the NASA Infrared Astronomical Satellite (IRAS) in 1983, and continued to glow brightly for 25 years. The dust was thought to be due to collisions between forming planets, a normal part of planet formation. Like Earth, warm dust absorbs the energy of visible starlight and reradiates that energy as infrared, or heat, radiation.

The first strong indication of the disk's disappearance came from images taken in January 2010 by NASA's Wide-field Infrared Survey Explorer, or WISE. An infrared image obtained at the Gemini telescope in Chile on May 1, 2012, confirmed that the dust has now been gone for two-and-a-half years.

http://www.nasa.gov/mission_pages/WISE/news/wise20120705.html

Perhaps something collected it?

[M Paul Lloyd]

Perhaps something collected it?

Or.... the stars solar wind literaly blew it away?

[nemisis1960]

Perhaps something collected it?

maybe there is a giant dyson out there hovering all the dust up

Dyson Dust Corp

clears all unwanted dust were ever it is in the universe

could the sun have eradiated it some way

[M Paul Lloyd]

I'm still clinging to the idea that the stars solar wind blew it away, after all our solar system is relatively free of such material and I'm pretty sure the same principle applies.

[Shadowwolf]

But achieved in such a short space of time? That's the big issue here, that the dust has vanished in such a short period that in astronomical time scales is incredibly sudden.

[M Paul Lloyd]

I wouldn't like to guess but I'm left wondering if our ideas about the rate of such changes are quite as accurate as we like to think?

[MikeG]

The solar wind is essentially radiation. Although it has been shown to push a solar sail, this has a huge surface area and has been designed to harness this effect. Could a solar storm really affect so many dust particles, especially within such a short time period?

[M Paul Lloyd]

Well solar flares can travel at speeds of up to 2,000,000 miles per hour and typically reach Earth within a day or so, which is fair licking along, but is it actually fast enough?

Neptune for example, is around 2,800,000,000 miles from the Sun so as a rough guide, if our Sun were subject to similar conditions and a truly enormous solar flare, or series of same accelerated the dust to just 1,000,000 mph, (and my calculations are right?) it would take about about 120 days for the dust 'wave' to clear the orbit of Neptune.

So I reckon a couple of years could just be long enough. Sadly we seem to have been looking the other way at the time.

[Shadowwolf]

I'm still clinging to the idea that the stars solar wind blew it away, after all our solar system is relatively free of such material and I'm pretty sure the same principle applies.

Indeed our system is from our perspective but a good deal of that has been via the formation of the planets and quite a long time for it to happen. This is a much younger system, besides if the solar wind could blow it away so rapidly then would that not prevent planets from ever forming as their constituent material is ejected?

The solar flare also seems an unlikely candidate as flares tend to be in a fairly limited direction and not omni-directional, the press release by the Gemini Observatory also says that they could see no evidence of flare.

I wouldn't like to guess but I'm left wondering if our ideas about the rate of such changes are quite as accurate as we like to think?

I reckon it is almost a certainty that our models of system formation and such are the current best approximation of what transpires and likely are missing much. However, if system dust clouds vanished so rapidly then they would likely be an extreme rarity which they are not as far as I know.

[KingPhillip]

There are two accepted premises in the discussion so far:
1) the distribution of dust is balanced along the equatorial plane of the young star, and
2) the orbit of the dust is less than the few years it has been absent.

The artist's concept pictured should have been replaced by the 1983 IRAS colorized dataset of the young star along with a current colorized dataset. The artist's concept is too prejudicial. Even the mention of Saturn's rings is incomparable. I've yet to see an infrared dataset of dust swarming around a young star. And I don't know what it means when it is claimed the dusts are gone. The infrared glow may be gone after the 25 years it was observed. But they might not be equivalent.

As a computer once chimed (Star Trek original series), "Insufficient data."

[M Paul Lloyd]

This is a much younger system, besides if the solar wind could blow it away so rapidly then would that not prevent planets from ever forming as their constituent material is ejected?

I'm not sure but I seem to recall reading something a while back to the effect that accretion discs are not as straight forward as was once thought, so the dust may not be as significant as supposed?
But I could be wrong.

[quote= "KingPhillip"]
As a computer once chimed (Star Trek original series), "Insufficient data."[/quote]

A very good point.