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Talk:YZ Cassiopeiae

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Notes

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To get details of the star system components, I downloaded and uncompressed part of Tokovinin's multiple star catalogue described here:

The catalogue files can be obtained from: ftp://cdsarc.u-strasbg.fr/pub/cats/J/A+AS/124/75/

This is the line from catalog.dat that describes YZ Cas:

00390+7426  0 45 39.1  74 59 17   -15   -22    9.0 0.0112 HIP 3   21 Cas, YZ Cas
IDS (1900)  RAhm RAs  +DEddmmss PMras PMdec Radvel Parall Pcd n T Name
n = number components
Pcd is Parallax code: HIP - trigonometric Hipparcos

These two lines from systems.dat give the system component details:

00390+7426    1 AB  Crphm   7.50   36.000" 160  5.66 A2IV  11.25 0.96    3.66s   0.80a H 122
00390+7426   11 Aab S2,E    0.65    0.916m   0  5.73 A2IV   8.63 F2V     2.31*   1.35* SB 41,  YZ Cas
IDS (1900) Leve Com Type   logP  Sep/Axis  PA  Vmag1 SP1   Vmag2 SP2   solMa1  solMa2  Remark
  • logP is Logarithm (base 10) of period in days
  • solMa1 is Mass of the primary,
  • solMa2 is Mass of the secondary, each is followed by the Mass estimation code, see note (3)

Note (3): Mass codes:
         * - given in the original publication
         a - estimated from spectral type or B-V color index from Allen tables
         s - sum of masses for the sub-system(s)
         q - estimated from primary mass and mass ratio of SB2
         m - minimum secondary mass for SB1
         v - estimated from magnitude difference of a visual binary
         : - uncertain, magnitude difference assumed to be 2 mag.

From some of the above data I derived the basic information for the article.

Tokovinin's later 2002 publication J/A+A/382/118 includes radial velocity measurements for YZ Cas B, but I did not use them.

Calculations used for deriving distances:

  • A-B = tangent(36.1 arcseconds) * 89 Parsecs = 3 212.9 Astronomical Units
  • AB-C = tangent(0.000916 arcseconds) * 89 Parsecs = 0.081524 Astronomical Units (I did not use this)

-84user (talk) 19:33, 5 September 2008 (UTC)[reply]