HD 188753, Gamma Cephei, other exoplanet binary stars

Post requests, images, descriptions and reports about work in progress here.
Topic author
ajtribick
Developer
Posts: 1855
Joined: 11.08.2003
With us: 21 years 3 months

HD 188753, Gamma Cephei, other exoplanet binary stars

Post #1by ajtribick » 10.12.2005, 18:21

Here is a file containing a few more binary stars which have planets around one component. It should be placed in the extras folder.

Image

I've been nagging people about this for a while, but apparently the handling of extrasolar.stc and nearstars.stc with Fridger's large binary catalogues hasn't been finalised yet, and there are several extrasolar binary systems which haven't been implemented.

SIMBAD was used to obtain the data. Systems for which no magnitude information was available were not implemented.

HD 41004 was not implemented because of lack of positional information for the secondary component (the values given seemed to be those for the primary but truncated to 2 decimal places). This system probably could do with some attention - the secondary has a brown dwarf companion, for which there are some elements here, though I haven't found anything about the orbit/position of the secondary itself.

There are also these stars, which have positions given relative to the primary in terms of separation and position angle, not sure how to convert this to RA/Dec.

Systems implemented:

  • HD 188753
  • Gamma Cephei
  • Rho1 Cancri
  • HD 219542
  • HD 196885
  • HD 142022


The barycentre positions used for HD 188753 and Gamma Cephei are actually the positions of the A components - I do not have positional data to calculate a better position. The inclination and principal argument of the node of the HD 188753 B-C system were taken from the A-(B-C) system as the actual values are unknown.

Note that the planet in the HD 219542 system orbits the B component, so extrasolar.ssc (in the data folder) should be edited to read:

Code: Select all

"b" "HD 219542 B"   # HD 219542 B
{
   Texture "exo-class3.*"

   Color  [0.53 0.62 1]
   Albedo 0.1

   Mass       100     # M.sin(i) = 0.3 jupiters
   Radius     84000
   Oblateness 0.09

   InfoURL "http://vo.obspm.fr/exoplanetes/encyclo/star.php?st=HD+219542+B"

   EllipticalOrbit {
      Period          0.3069
      SemiMajorAxis   0.46
      Eccentricity    0.32
      ArgOfPericenter 130
      MeanAnomaly     356
   }

   RotationPeriod  19 # tidal slowing significant
}

AltSurface "limit of knowledge" "HD 219542 B/b"
{
   Texture "extrasolar-lok.*"
}
Last edited by ajtribick on 11.12.2005, 23:14, edited 1 time in total.

Topic author
ajtribick
Developer
Posts: 1855
Joined: 11.08.2003
With us: 21 years 3 months

Post #2by ajtribick » 11.12.2005, 22:33

I added HD 188753 and Gamma Cephei. Thanks to Dr Fridger Schrempp and Grant Hutchison for help with binary star orbital elements.

The barycentre positions used for HD 188753 and Gamma Cephei are actually the positions of the A components - I do not have positional data to calculate a better position. The inclination and principal argument of the node of the HD 188753 B-C system were taken from the A-(B-C) system as the actual values are unknown. This is a hideous fudge, but I'm not sure how to handle this better.

The HD 188753 system is a good case for why we should be able to use catalogue references in OrbitBarycenter. "HD 188753 A-(B-C)" just looks ugly.

Tleilax
Posts: 44
Joined: 22.03.2005
With us: 19 years 7 months
Location: Colorado Springs

Post #3by Tleilax » 15.12.2005, 08:47

Awesome!
Nothing suffocates you more than
the passing of everyday human events
Isolation is the oxygen mask you make
your children breath into survive

- Marilyn Manson


Return to “Add-on development”