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Re: (IAAC) Burnham's Stars

Hi All,
 
This is a discussion from the 33-doubles group at Yahoo! Groups from almost a year ago.
 
It doesn't contribute to the spetral discussion, but it shows some of the problems with this star - especially its mass distribution.
 
Anyway, I adds more information to the dis cussion.
 
Andrew
 
Note: I have all the measured data for these three stars  somewhere in my filing cabinet, that was gained from the US Naval Observatory in Oct last yeat. When I find it, I'll add to what it says.
 
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POST 33-double Yahoo Groups
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Andrew
 
From:  "ariane1au" <andjames@o...>
Date:  Sun Jan 13, 2002  10:16 pm
Subject:  Re: Gamma Andromedae - Clarification
 
Hi Everyone,
 
I have a little problem (some say it's a big one!) regarding
resolving the binary star Gamma Andromedae / Alamak / STT 38BC
(02039+4220) which is has been placed in a good position for
observation in the last months (and years).
 
I am writing some text on this colourful pair and I cannot find any
recent observaions. I looked at this pair in good seeing in 1982 and
split the two stars - but have observed it since. From the latitude
of Sydney, Australia at -34 deg it appears close to the horizon.
 
I liked the colour contrast, but presently the separation has dropped
to 0.45" @ PA 105 deg. In my opinion it is a rival for Alberio (if
not better!) As the orbit is so eccentic we have good and bad times
to see it - now is a bad time in thee 63-years period.
 
Does anyone have recent (or their last) observations of this star?
 
Regards,
Andrew James
 
Hi All,
 
To clarify the last post, I am talking about the companion
resolution "BC" and NOT the main primary coloured pair STF 205A-
BC "AB" which is about 27.9" apart along PA 245, and as dead easy in
most telescopes.
 
This is a triple star.
 
Andrew
 
Hi All,
 
If you want to look at the eccentric orbit of STT 38 BC go to;
 
http://ad.usno.navy.mil/wds/orb6/GIF/wds02039+4220b.gif
 
The Non Frames Page of the US Naval "Sixth Catalog" is at;
 
http://ad.usno.navy.mil/wds/orb6/orb6orbits.html
 
If you want to look at the elements.
 
Andrew
----- Original Message -----
From: FiskeM3@aol.com
To: netastrocatalog-announce@atmob.org
Sent: Thursday, January 23, 2003 11:55 PM
Subject: Re: (IAAC) Burnham's Stars

Well, since we're getting serious about this, :-) I took a look in the WDS database I downloaded from the web and imported into Access 2000 and found 3 records for WDSNum 02039N4220. Here is a field breakdown for them:

CatNum      Components      Last Obs.   PA        Sep      Mag1    Mag2    Class
STF 205     ASBC               2001           64         9.8       2.31      5.02      K3IIb
BAR  22     AD                    1898           245       27.9     5.1        15        K3IIb
STT   38     BC                    2000           103       0.2       5.1        6.3      B8VNAOV

Note that the PA and Sep info is from the last observation (listed). Also note that the spectral class listing for the first two entries is K3IIb. The data bible provided by the USNO states that the spectral types of two components are provided where space permits. It also says "See the Introduction for discussion." Unfortunately, the Bible introduction does not seem to be available on the USNO website. At least I could not find it after a brief search 5 minutes ago. Anyway, I don't know how they're formatting multiple spectral type entries.

From this information, it seems possible that the spectral type is being reported in applications like MegaStar and StarMap Pro only for the third entry.

One halfway suspects that the problem arises from the fact that amateur astronomers have become so focused on more "glamourous" deep-sky objects (like galaxies) that software designers haven't spent much time sorting out the admittedly complex doublestar catalog issues. Thank you Mr. Dobson!  :-)

Fiske
Kansas City

PS: I also checked Cartes du Ciel (the amazing free starmap software available on the internet) and found that the Almach doublestar info reported STF 205 A-BC and listed the primary as a spectral type K3IIb. It's been some months since I was messing about with it, but I did spend some time generating WDS data files for one of my starmap applications and it might have been Cartes du Ciel. (Can't recall specifically.) Anyway, if I did generate WDS files for this program, I might well have eliminated duplicate data entries from the file to fix reference problems. This could account for why the STF 205 entry appears in Cartes du Ciel on my computer.
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