Talk:IAU designated constellations by area
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The total area of all constellations can be verified by spreadsheet to be equal to the total area of the sky, as given in a note near the bottom of the page. Note that the earlier area given for Canis Minor was off by 1 sq. deg. and the area for Vulpecula was off by 10 sq. deg. -- Curps 01:41, 7 August 2005 (UTC)
What's the Correct Area of Serpens?
[edit]The footnote dividing Serpens into two sections rounds the section areas to just two decimal places. And indeed RASC's table lists them separately, with areas of 428.480 and 208.440 square degrees respectively. The problem is that their sum would be 636.920, not 636.928 as in Wikipedia's table. So who's correct?
I found another web site - http://homepage.mac.com/andjames/Page20501.htm - where the table also lists the two sections of Serpens separately. That table gives the areas as 428.484 and 208.444, differing from RASC's only in a "4" instead of a "0" being in the third decimal place of each number. That little difference makes the corrected sum - tada! - 636.928 square degrees.
The only problem comes with adding the columns. Ideally the total area of the 88 constellations should be 360^2 / pi or 41,252.96125 square degrees, rounded to 41,252.961 after three decimal places. A spreadsheet verifies that the RASC's areas (remember the 0's: 0 + 0 = 0) sum to 41,252.968 - an excess of just .007; however, Wikipedia's areas (remember the 4's: 4 + 4 = 8) sum to 41,252.976 - an excess of .015 square degree. Since even three decimal places is a rounding of the true indivual areas, some round-off error is likely when the areas are summed. But which sum is correct?
I've found a solution to the round-off problem. It just happens that when the areas are rounded to ONE decimal place (using the ROUND function on the spreadsheet) and added, the areas sum to precisely 41,253.0 square degrees, which is the correct value to one decimal place. And splitting Serpens into two is no problem, since 428.5 + 208.4 = 636.9, all also correct to one decimal place.
The table at http://calgary.rasc.ca/constellation.htm#list now has the areas for Serpens Caput and Cauda rounded to the same three decimal places as the rest of the table. Thanks to Larry McNish of the Calgary RASC for that fix. --Glenn L (talk) 04:12, 26 March 2010 (UTC)
Column sorting
[edit]Currently the right ascension and declination columns do not sort properly. Declination is almost right, except that the northern hemisphere numbers are in reverse order, and should be listed after the southern hemisphere (if you're going from smallest to largest values, reverse of that otherwise). But the right ascension sorting completely baffles me - it looks almost random. Not numerical, not alphabetical, no idea what it's thinking. Is there anything simple we can do to fix this? (On other wikis, I've seen a simple template that makes hidden text which doesn't display but is used as a sort-key. Not sure where that is here, or if that's accepted practice for this sort of thing.) Alternatively, what would it take to code the sorting algorithm to be smart enough to understand right ascension and declination values and sort them properly? May be more trouble than it's worth. Failing that, it might be better to simply make those columns un-sortable, because as-is, they do nothing useful when sorted. Lurlock (talk) 06:03, 4 November 2013 (UTC)