Beta pictoris sytem

Hi
I try to make articles on Beta Pictoris, its planets and its
discs of material, but it is not easy thing. Indeed I found a lot of
very blended information, and I really do not know how to sort out. No
information really contradicts other one, but there is so much that I
want to ask for your opinion. What is interessant, and what is
out-of-date?

I make you a flowchart with what I already have succeeds in sorting out.

Planet b is the imaged (end transiting?) planet

Planets "x" "y" and "z" are in resonance.

Planet "c" is a giant distant planet.

Discs A B and C are from this pictures




Inner belt of silicates
Mean distance: 6,4 UA
Incline: 14°?

Beta Pictoris b
Mass: 8(+5/-2) Mj
Orbite: (photo and "transit" data) 7,6-8,7 UA
Period: 15,9-19,5 years
Incline: no data

Planet "x"
Mass: 2-5 Mj
Orbit: 12 UA
Period: 67 years
Incline:3°
Close to 1:3:7

Disc of silicates "A"
Mean distance: 16 UA
Incline: 14°?
with ring of planetesimals at 14 UA

Planète "y"
Mass: 0,5Mj
Orbit: 25 UA
Close to 1:3:7

Disc of silicates
Inner limit: 25 UA
Mean distance: 30 UA
With ring of planetesimal: 28 UA

Planète z
Mass: 0,1Mj
Orbit: 44 UA
Close to 1:3:7

Ring of planetesimal at 52 UA

[Planet "c"
Mass: 10 Mj
Orbit:70 UA
Incline: 2,5°
Period: 450 years] Non observed in 2003

Disque B
Ring of planetesimals at 82 UA and 100 UA (Pluto size objects)
Outer limit: 130? 260? UA
Incline: 4° 5°? (Asymetrical?)


Disque C
Rings: 500-800 UA
Outer limit : (1100+/- 20%=880-1350 UA) or (1835/1450? UA) (differents sources)

+ comets, formation of a Oort Cloud and wind of meteoroids in the solar system

Planets of Beta Pictoris Revisited
http://arxiv.org/abs/astro-ph/0701526

Before the discovery of Bet Pic b, it was hypothesized that a 2 M_j planet at 12 AU (e ~ 0.1), a second 0.5 M_j planet at 25 AU (e ~ 0.01), and a third 0.1 M_j planet at 44 AU (e ~ 0.01) might exist to explain the structures in the disk. It was also suggested that perhaps the first and second planets are nearly in a 3:1 resonance, and the first and third planets are nearly in a 7:3 resonance. Then Bet Pic b was discovered at 8 AU. I'm not sure if this makes the orbit of a planet at 12 AU unstable or not. Probably? That paper also goes into detail of the structure of the disk, pointing out four structures in the disk at ~6.4 AU, ~16 AU, ~32 AU, and ~52 AU. It's the most comprehensive examination of the Beta Pictoris system before the announcement of the 8 M_j Bet Pic b.

It may be that the imaged planet (if it is confirmed to be bound to Bet Pic) may exist in addition to a number of those previously hypothesized planets.

Those are some neat images of the Bet Pic disk. O_o. I don't know if you're aware of this one from HST, but it's pretty cool:


Here's a more recent paper, submitted after the announcement of Bet Pic b, and attempts to identify structures in the disk.

VLT/NACO coronagraphic observations of fine structures in the disk of beta Pictoris
http://arxiv.org/abs/0901.2034

Abstract wrote:

We present ground-based observations of the disk around the A-type star $\beta$ Pictoris to perform a close inspection of the inner disk morphology. Images were collected with NACO, the AO-assisted near-IR instrument on the VLT (ESO) which includes two types of coronagraphs: classical Lyot masks and phase masks. In this program we took advantage of both types of coronagraphs in two spectral bands, H-band for the Lyot mask and Ks-band for the phase mask. In addition, we simulated an extended object to understand the limitations in deconvolution of coronagraphic images. The reduced coronagraphic images allow us to carefully measure the structures of the debris disk and reveal a number of asymmetries of which some were not reported before (position, elevation and thickness of the warp). In this program, the circumstellar material is visible as close as 0.7" ($13.5 $AU) owing to the phase mask while the Lyot mask generates artifacts which hamper the detection of the dust at separations closer than 1.2" ($23.2 $AU). The point source detection limit is compared to recently published observations of a planet candidate. Finally, the simulations show that deconvolution of coronagraphic data may indeed produce artificial patterns within the image of a disk.