Talk:5 Astraea

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia

Pronunciation[edit]

I changed the pronunciation from as-trye'-a. True, <æ> represented [aj] in Latin, but in English it regularly becomes <e> (ee or eh depending), as in encyclopædia. The mythological refs I've checked are universal in giving as-tree'-a.

Densities[edit]

A paper [Krasinsky, Icarus, Vol. 158, p. 98 (2002)] gives recent calculations for the mean densities of C, S, and M class asteroids as 1.38, 2.71, and 5.32 g/cm3. (here "C" included Tholen classes C,D,P,T,B,G, and F), while "S" included Tholen classes S,K,Q,V,R,A,E). Assuming these values (rather than the present ~2 g/cm3) is probably significantly more accurate for the mass of asteroids whose mass has not been otherwise measured, although there is still heaps of variation due to porosity, etc. Deuar 11:39, 16 November 2005 (UTC)[reply]

Dimensions[edit]

The Lopez-Gonzales reference (2005) gave diameter ratios a/b=1.35, b/c=1.5, (where the dimensions are a×b×c) from photometry. Combining these with the IRAS mean diameter of d=119.1 km using abc=d3, gives the dimensions 167×123×82 km. Deuar 18:11, 16 November 2005 (UTC)[reply]

Mass[edit]

From Table 6 of Michalak (2001), the assumed mass for 5 Astraea in his perturbation calculations is 0.015x10-10 times the mass of the sun, thus 1.9891x1030 kg x 0.015x10-10 = 3.0x1018 kg (to two significant digits). Michalak states "Asteroid masses in these models are taken from Table 6 and one should realize that they can be erroneous." One assumes Michalak's number is an educated guess, and sadly since this is apparently the only paper (up to this writing) containing any mass determination for 5 Astraea, 3.0x1018 kg is it. -- Robert.Baruch (talk) 15:06, 16 February 2010 (UTC)[reply]

I generally compare asteroids to Ceres simply because the Sun is kind of big for an asteroid comparison. :) I used 2.9E+18 simply because I have a tendency to truncate more than round-off, and even though the mass is an assumption, I wanted to come in low with the estimate. Of course any notable error in the mass of Astraea could potentially throw off calculations for the perturbing asteroid.-- Kheider (talk) 18:01, 16 February 2010 (UTC)[reply]

Dead link[edit]

During several automated bot runs the following external link was found to be unavailable. Please check if the link is in fact down and fix or remove it in that case!

--JeffGBot (talk) 20:24, 19 June 2011 (UTC)[reply]

External links modified (January 2018)[edit]

Hello fellow Wikipedians,

I have just modified one external link on 5 Astraea. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 18 January 2022).

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 12:01, 22 January 2018 (UTC)[reply]

Retrieved from "https://en.wikipedia.org/w/index.php?title=Talk:5_Astraea&oldid=1197069039"