polar alignment

Dollard Desmarais · Post #1by **Dollard Desmarais** » 02.11.2004, 17:54

I wonder if anyone on this forum could help me. My scope is a 200mm f/5 GEM reflector. On the west coast of Canada, clear skies suitable for observing are few and far between. I've only been into star gazing for less than a year and am still grappling with polar alignment. All I want to do at this stage is star hopping and I'm still trying to learn to recognize the constellations. My scope is equipped with both RA and DEC drives as well as a polar alignment scope. I haven't been successful in focusing on Polaris and then manually moving my tripod to the NCP as some have suggested I do. I would like to further explore this link:

http://www.syz.com/rasc/polralgn.htm

I have been able to identify all the reference stars except for Theta Aql. If I type in Enter\Theta Aql\Enter in Celestia I get nothing. Can anyone identify this star by some other name?

Post #2by **selden** » 02.11.2004, 18:50

Unfortunately, Celestia does not understand the fully spelled out name of the letter "Theta". You'll have the least problems if you use the formal three letter abbreviations defined by the IAU for the letter and for the constellation.

In other words, use
<return>TET Aql<return>

*sigh*

Evil Dr Ganymede · Post #3by **Evil Dr Ganymede** » 02.11.2004, 18:52

It can be found by typing in Enter\65 Aql\Enter - it is definitely there, it's just not being recognised by the text entry thingie.

Interestingly, I can't find ANY "theta" stars in Celestia. Maybe there's a bug there in the parser.

Evil Dr Ganymede · Post #4by **Evil Dr Ganymede** » 02.11.2004, 18:54

TET mean "theta"?! That's... odd - no wonder I couldn't find it, it's hardly obvious. Is there a reason why Celestia can't parse "theta" or "the"?

Guest · Post #5by **Guest** » 02.11.2004, 19:38

Here is a link to the approved three-letter abbreviations for the Greek alphabet:

http://simbad.u-strasbg.fr/guide/chA.htx

Dollard Desmarais · Post #6by **Dollard Desmarais** » 02.11.2004, 19:46

Three-letter except for pi, mu, nu!!!

Post #7by **selden** » 02.11.2004, 19:52

Well, that depends on whether or not you consider a period (aka "full stop") to be a letter, I suppose.

If you look very closely, you will notice that the "abbreviations" for pi, mu and nu are actually "pi.", "mu." and "nu."

Remember, traditionally most astronomical data files are optimized for use with Fortran. Fixed width fields are easy to handle in FORMAT statements. Variable width fields are not so easy.

Dollard Desmarais · Post #8by **Dollard Desmarais** » 02.11.2004, 20:09

Thanks Selden. I thought those dots were simply my eyesight starting to fail.

Evil Dr Ganymede · Post #9by **Evil Dr Ganymede** » 02.11.2004, 22:08

Agh, anglicised greek letters drive me nuts!

"mu"? "nu"? "upsilon"? Greeks don't pronounce those letters like that! (it should be "mee", "nee", and "ipsilon"). And "kappa" should be "gappa", and "delta" should be "thelta", and "gamma" should be um, "gamma' with a rolling "g". No wonder english pronounciation of greek words is so terrible!

I wonder why they use "ksi" instead of "xi." on that list though.

Post #10by **t00fri** » 02.11.2004, 22:29

Evil Dr Ganymede wrote:Agh, anglicised greek letters drive me nuts!

"mu"? "nu"? "upsilon"? Greeks don't pronounce those letters like that! (it should be "mee", "nee", and "ipsilon"). And "kappa" should be "gappa", and "delta" should be "thelta", and "gamma" should be um, "gamma' with a rolling "g". No wonder english pronounciation of greek words is so terrible!

I wonder why they use "ksi" instead of "xi." on that list though.

I have no problems with the IAU convention. I agree, though, that people with a greek background do have severe problems with this. I seem to remember that our esteemed Evil Dr. Ganymede does indeed have greek roots!?

Bye Fridger