Wikipedia:Peer review/Beta Pictoris/archive1

Beta Pictoris

• A script has been used to generate a semi-automated review of the article for issues relating to grammar and house style; it can be found on the automated peer review page for July 2009.

This peer review discussion has been closed.
I've listed this article for peer review because I want to try to get this article to featured status, having done major expansion work on it in the past. It is already listed as a Good article. The main areas I have concern about are whether the application of various formulae in the text violates WP:NOR, and that the language may be too technical in places.

Thank you, Icalanise (talk) 18:48, 7 July 2009 (UTC)

RJHall notes:

Overall it looks pretty good to me. I didn't see much in the way of potential terminology issues, save perhaps "refractory material" (but that's linked so it's probably not a problem). Here's a few thoughts on potential enhancements:

• Where formulae are used in notes, you might consider adding an inline cite for each formula (within the corresponding note).
• You could clarify why the "presence of significant amounts of dust around the star implies a young age of the system".
• You might want to explain the statement that "its very young age makes the noise even worse".
• Doesn't the high rotation rate also indicate a young star?
• Personally I like to see more details on the star itself. Perhaps you could add information on convection, magnetic field, CNO vs. P-P cycle, &c. An estimated main sequence lifespan would be good, as would be the star's ultimate fate.
• There are perhaps an excessive number of parenthetical structures in the text. I believe that some reviewers don't care for those because they don't work well with page-reading software for the vision impaired.[1]

Nice work. Thanks.—RJH (talk) 22:02, 7 July 2009 (UTC)

Thanks for your suggestions. A few questions arising from your points.

• Can ref tags be nested? Last time I checked you couldn't do that, but maybe the functionality has since been added?

  they can be nested using {{#tag:ref|Ref content|name=NAME|group=GROUP NAME}} construct like in Oberon (moon). Ruslik_Zero 12:30, 17 July 2009 (UTC)

• Agreed about the evolution - it would be preferable to get a source to directly quote main sequence lifetime, but how far could we push taking values from, e.g. the Geneva Grids of stellar evolution before it becomes too much like synthesis?

Icalanise (talk) 17:01, 9 July 2009 (UTC)

• For Vega I tried putting a source and a range in the footnote, then just put an approximate value in the text. It seemed to be acceptable to the FAC reviewers. At least nobody has called me on it yet. Shrug.—RJH (talk) 21:47, 20 July 2009 (UTC)

An apology: I have been rather busier than I had been expecting recently so haven't had time to address some points made above, I do plan to do so in the near future. Icalanise (talk) 21:06, 16 July 2009 (UTC)

No problem. I figured you'd get to them (or not) when you had the time. Thanks.—RJH (talk) 21:47, 20 July 2009 (UTC)

Review by Ruslik:

1. The article says that the disk is made of 'gas and dust'. However little information is provided about the gas component. The article only says that it is 'carbon rich'. Can some information about the mass, thinkingness, spatial extent and the chemical composition of the gas disk be added? Is this gas primordial or a result of evaporation of planetesimals? (The latter is probably true.) See [2], [3], [4] and [5].
2. The distance to Beta Pictoris was found by measuring the star's trigonometric parallax. This sentence should be moved to the second paragraph of this section.
3. As Beta Pictoris rotates fast, can this cause its poles to be hotter than the equator like in the case of Vega? This is should be discussed (if possible). Fast rotation would also distort its shape making it into an oblate spheroid.
4. It would be good if the article discussed coronal and chromospheric activity (See [6]) and also X-ray emission. This discussion should be correlated with the discussion of internal structure, magnetic fields and convection.
5. Alternatively it may be passing through an unknown phase that might also have occurred early in the development of our solar system: in our solar system there are carbon-rich meteorites known as enstatite chondrites, which may have formed in a carbon-rich environment. The enstatite chondrites are not the most carbon rich meteorites (they only slightly enriched in carbon as compared to ordinary chondrites). The most carbon rich are carbonaceous chondrites.
6. and the warps and inclined rings in the inner disk suggest a massive planet on an inclined orbit is disrupting the disk. What is 'the inner disk'?
7. The separation in the radial direction, that is unknown, so this is a lower limit on the true separation. This sentence needs to be rewritten.
8. if the planet is in an orbit with a semimajor axis of 8 AU, its orbital period would be 16 years and it would currently be too close to Beta Pictoris as seen from Earth to be detected. But the planet has been already detected, has not it?

Ruslik_Zero 12:09, 17 July 2009 (UTC)

Responses to some of Ruslik0's points.

• Definitely agree that more about the star's characteristics is needed here. Not sure that there is going to be much oblateness though, doing a back-of-the-envelope estimate assuming a "Roche spheroid" (i.e. gravitational+centrifugal potentials) I get that the polar radius is going to be roughly 95% of the equatorial one, this is rather less distorted than stars such as Achernar (64%) [7], Alderamin (80%), Rasalhague (83%) [8] or Altair (81%) [9], so I'd guess that there isn't going to be much gravity darkening either. I haven't found any references about interferometric measurements of the star's shape.
• I used the example of the enstatite chondrites as that was what was mentioned in the reference. Probably should mention the carbonaceous chondrites too though.
• Ok being a pedant inner disk should be "innermost regions of the disk" I guess...
• Planet has already been detected, but the image dates back to 2003 and the planet's orbital motion would change the apparent separation. Agree that this needs to be explained better.

Icalanise (talk) 19:57, 27 July 2009 (UTC)