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Catalogue references in .stc files

Posted: 20.11.2005, 13:43
by ajtribick
A feature that I think is needed in light of t00fri's binary star catalogues is the ability to use catalogue references for the OrbitBarycenter field.

For example, the following .stc file does not work:

Code: Select all

Barycenter 999998
{
   RA 119.917516  # mass ratio 1.09:0.92
   Dec -60.837128 #
   Distance 4.365
}

"HIP 999998 A"
{
   OrbitBarycenter "HIP 999998"
   SpectralType "G2V"
   AbsMag 4

   EllipticalOrbit {
      Period          79.914
      SemiMajorAxis   10.765   # mass ratio 1.09:0.92
      Eccentricity    0.5179
      Inclination   82.986
      AscendingNode   67.726
      ArgOfPericenter 3.772
      MeanAnomaly     200.119
   }
}

"HIP 999998 B"
{
   OrbitBarycenter "HIP 999998"
   SpectralType "K0V"
   AbsMag 5

   EllipticalOrbit {
      Period          79.914
      SemiMajorAxis   12.755   # mass ratio 1.09:0.92
      Eccentricity    0.5179
      Inclination   82.986
      AscendingNode   67.726
      ArgOfPericenter 183.772
      MeanAnomaly     200.119
   }
}


The barycenter HIP 999998 is created as expected, however the OrbitBarycenter references do not work.

In addition, it would be useful if stars created in stc files could use catalogue references: for example the following code does not work as expected:

Code: Select all

"HD 911811"
{
   RA 265.834167
   Dec 35.970000
   Distance 8.290
   SpectralType "M2.0V"
   AppMag 7.47
}


This creates a name entry in the database, and the object cannot be selected using the text entry field (even using autocomplete). Similar problems apply to using SAO numbers (also HIP references, though these have a defined mechanism for addition).

Another feature that may be appropriate would be some kind of placeholder string which would allow characters to be appended to barycentre designations, for example "^ B" would take the individual names from the object referenced in the OrbitBarycenter field and add " B" to them. While this is not an essential feature, it would help when implementing real binary systems so that name changes would only have to be dealt with in the starnames.dat file.