Why are astronomical coordinates so horrendously complex?

[NoXion]

OK, so I'm mucking about in Celestia trying to rename a star, but apparently it's not enough to just supply the new name in a supplementary .STC file, you have to also include all the positional data of the star in question within said file. Now, this wouldn't be so difficult if Celestia and/or astronomy had a remotely sensible coordinate system, or at least had only one such system and stuck to it. Instead I get this:

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Distance from Sol: 28.377 ly

Right Ascension: 6h 52m 18s
Declination: -5 Degrees 10' 25"

Ecliptic Longitude: 104.78 Degrees
Ecliptic Latitude: -27.94 Degrees

Galactic Longitude: 217.64 Degrees
Galactic Latitude: -2.16 Degrees

This is the positional data, as presented within my version of Celestia, for the star HIP 32984, also known as HD 50281 and SAO 133805 because hey, it wouldn't be astronomy without multiple confusing cataloging systems! Unfortunately I cannot simply cut+paste these values into the .STC file because according to this document I need to specify the RA and Dec in "fractional degrees". I looked on Google for some kind of conversion tool in some vain attempt to make my life easier but for some weird reason Google hasn't heard of fractional degrees and kept directing me to converters involving decimal degrees instead. Are these different names for the same thing?

I guess what I am looking for is an easy way (or at least a set of formulas I can write down and use) to convert between the various different astronomical coordinate systems. Annoyingly enough, .DSC files (which define the positions and properties of nebulae within Celestia) define Right Ascension in fractional Hours rather than fractional degrees, for no obvious good reason. This makes precise alignment of stars and nebulae within Celestia an irritating game of trial and error. Thanks Obama!

Any help would be appreciated. I don't expect many people here to have experience with Celestia, but since my precise problem is with celestial coordinates rather than with anything idiosyncratic to the program itself I'm hoping that someone here might be able to help. Thanks in advance and apologies to the mods if this thread could have been better placed.

[madd0ct0r]

fractional degree: http://zonalandeducation.com/mmts/trigo ... MinSec.htm

[Terralthra]

60 arc-minutes to a degree. 60 arc-seconds to an arc-minute. 30.5 degrees = 30 degrees, 30 minutes.

[Eternal_Freedom]

Hmm, I'm bookmarking that, that could prove very useful.

On the main issue, we have several different coordinate systems for different purposes. RA/Dec tells you where things are in the night sky regardless of where you are on Earth. It's also more useful than Ecliptic or Galactic longitude/latitude for locating extra-galactic objects, since they (obviously) aren't covered by the galactic coordinate ystem since they aren't in our galaxy.

Frankly though, RA/Dec is the basic, default coordinate system used by pretty much everyone in the astronomical community. Hell, we only briefly touched on galactic lat/long in my astronomy degree, a cursory glance at wikipedia suggests it's mostly used in regards to radio astronomy. It's quite a nifty system but it's nowhere near needed yet.

[SMJB]

I didn't even know that the ecliptic and galactic systems were things until this very minute. Everything I've ever seen just used right ascension/declination.