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Fraser
2006-Jun-27, 04:43 AM
Astronomers from the University of St. Andrews have found evidence that a ring of dust around nearby Epison Eridani is rotating. The observations were made using the Submillimetre Common User Bolometer Array (SCUBA), which images the sky in the near infrared spectrum. This gives evidence to the theory that the disks of gas we see around newborn stars will eventually go on to become planets. In fact, the clumps of material tracked by the astronomers could even be newly forming planets themselves, still embedded in a vast disk of gas and dust.

Read the full blog entry (http://www.universetoday.com/2006/06/26/rotating-disk-could-contain-newly-forming-planets/)

antoniseb
2006-Jun-27, 12:10 PM
This is very cool result. Epsilon Eridani is a very nearby star, and the prospects for getting relatively detailed knowledge of a key part of the planet forming process by looking at this neighbor of ours over the next few decades is great. I wonder what SCUBA-2 will be able to see.

AstroStart.nl
2006-Jun-27, 04:23 PM
There are three different names in the article:

Epison Eridani - 'Astronomers from the University of St. Andrews have found evidence that a ring of dust around nearby Epison Eridani is rotating.'

Epsilon Eridani - 'In a recent paper entitled Detecting a Rotation in the Epsilon Eridani Debris Disc'

Episilon Eridani - 'The rate of motion of these clumps matches the theory that the ring around Episilon Eridani is in fact a protoplanetary disk.'

:P

Tigran
2006-Jun-28, 02:37 PM
Interesting, but it seams that there is some discrepancy in the article...


The observations were made using the Submillimetre Common User Bolometer Array (SCUBA), which images the sky in the near infrared spectrum.

SCUBA "images" only in SubMM:
http://www.jach.hawaii.edu/JCMT/continuum/intro.html
Near-Infrared spectrum is around 1-2.5 microns, but SCUBA's main observing bands are 450 and 850microns, which is called SubMM.

Bynaus
2006-Jun-28, 04:20 PM
Hm, there's a strange mistake in the article (or am I mistaken?).

On one hand:


they would complete an orbit every 130 years

On the other:


If they were located in our Solar System, these planets would be a little further out than Pluto.

This doesn't make sense: Eps Eri is a lightweight star - it is lighter than the sun in fact. Orbits at similar distances should take longer to complete (e.g., more than 248 years of Pluto at 30 AU), not shorter (130 years). One of the two values must be wrong.

antoniseb
2006-Jun-28, 04:24 PM
I would guess that to be a radius vs. diameter communication problem somewhere along the line. BTW, Pluto's Average distance to the Sun is 39.4 AU.

Bynaus
2006-Jun-28, 05:10 PM
BTW, Pluto's Average distance to the Sun is 39.4 AU.

You are right.


I would guess that to be a radius vs. diameter communication problem somewhere along the line.

Eps Eri a has 77% of the mass of the sun. At 130 years, this would translate into a distance of (3rd root of(130^2 * 0.77) = 23 AU. "A little farther out than pluto", combined with a radius / diameter problem could, as you suggested, indeed solve the problem.