This article is rated Start-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | |||||||||||||||||
|
Daily pageviews of this article
A graph should have been displayed here but
graphs are temporarily disabled. Until they are enabled again, visit the interactive graph at
pageviews.wmcloud.org |
The discovery of a satellite for 2003 AZ 84 has been published in IAUC 8812. RandomCritic 02:05, 25 February 2007 (UTC)
Why the 2-sig figure for the mass in the info box if the mass is unknown? Is that calc'd from the orbit of the satellite, and the text hasn't been updated? — kwami ( talk) 21:12, 4 July 2011 (UTC)
Dwarf Planet & Plutoid Headquarters = Yes? -- Kheider ( talk) 17:03, 17 January 2012 (UTC)
Known for more than ten years. Have any names been proposed/considered yet? Steinbach ( talk) 13:17, 27 September 2013 (UTC)
A stellar occultation by that asteroid has been observed on November 15, 2014, which revealed that the asteroid in fact is a very elongated body with a dimension of 833 km x 576 km, in contradiction to the assumption that the body is a spheroid. I'm not sure if this should be added to the article before the result has found it's way into a peer-reviewed publication. Source: http://sendaiuchukan.jp/data/occult/1411-2003AZ84-red.gif
I've discovered another problem... In another section the wiki-article states that the asteroid's lightcurve amplitude is large (abt. 0.15 mag). Isn't that a contradiction to the other statement? Renerpho ( talk) 15:13, 19 May 2015 (UTC)
The study on 2003 AZ84's ellipsoidal shape is quite interesting yet it isn't mentioned as much in the article. I've added a bit of information on it. — Preceding unsigned comment added by 107.210.28.247 ( talk) 00:50, 6 February 2019 (UTC)
(Disclaimer. I realise that the following may in part be
original research. I believe it is still relevant to how the sources are presented/used in the article.)
I believe that the sources used in this article contradict each other. That itself isn't a problem (reaching scientific consensus often includes opposing views), but here the situation is different, because those conflicting sources heavily rely on each other, by cherry-picking results from the other papers without realising the apparent contradictions.
This Wikipedia article cites the paper
(Dias-Oliveira, 2017) as its source for the derived density of 0.87±0.01 g/cm³. That paper finds that the shape of 2003 AZ84 is highly elongated, and derives a density based on an
assumed shape (an assumption that is equivalent to hydrostatic equilibrium - a strong assumption, as mentioned in the article), but also based on the rotation period.
In the article lead, this Wikipedia article also cites
(Tangredi, 2008), which lists 2003 AZ84 as a "Case II - Sphere or MacLaurin ellipsoid with small albedo spots". If taken at face value, (Tangredi, 2008) means that the period determination by
(Sheppard, 2003) is only consistent with the double-peak solution of 13.4 hours, not the single-peaked 6.7 h. (Compare page 2 of the Sheppard paper.) That's also the value that the Lightcurve Database prefers.
[1]
There are two problems with this:
1. (Dias-Oliveira, 2017) assumes the period from the single-peaked solution. They cite
(Thirouin, 2010) as their main source, which, citing (Sheppard, 2003), states that the possible double-peaked solution is "apparently no more likely" than a single peak. However, that conclusion is no longer valid in light of the findings from (Dias-Oliveira, 2017) itself, namely its highly elongated shape, as explained in (Sheppard, 2003). Consequently, the density derived in (Dias-Oliveira, 2017) is based on a value for the rotation period that is inconsistent with the findings of that very paper.
2. If the density derivation was correct, and the lightcurve was single-peaked, then (Sheppard, 2003) concludes that it must be caused by albedo spots, in contradiction with (Tangredi, 2008). That paper's classification of 2003 AZ84 was doubtful to begin with (note the "?"), so a contradiction is not surprising. This doesn't resolve problem #1 though, since the density and assumed shape from (Dias-Oliveira, 2017) imply that 2003 AZ84 is a "Case III – Jacobi ellipsoid with reasonable density". In any case, (Tangredi, 2008) is outdated and probably shouldn't be used as the sole support for a claim in the article lead.
Renerpho (
talk) 08:10, 7 July 2019 (UTC)