Mass of objects in Celestia

[PlutonianEmpire]

looking in the extrasolar.ssc at one of the planets in gliese 876, and i was wondering, how does mass "work" in celestia?

[hank]

looking in the extrasolar.ssc at one of the planets in gliese 876, and i was wondering, how does mass "work" in celestia?

It doesn't.

- Hank

[PlutonianEmpire]

then what is this?

Code: Select all

"d" "Gliese 876"   # IL Aqr
{
   Texture "venuslike.*"

   [b]Mass      7     # M.sin(i) = 7 earths[/b]
   Radius     12600

   InfoURL "http://vo.obspm.fr/exoplanetes/encyclo/star.php?st=Gliese+876"

   EllipticalOrbit {
      Period          0.0053
      SemiMajorAxis   0.20806
      MeanLongitude   45
   }

   # likely to be in captured synchronous rotation
}

AltSurface "limit of knowledge" "Gliese 876/d"
{
   Texture "extrasolar-lok.*"
}


"c" "Gliese 876"   # IL Aqr
{
   Texture "jupiterlike.*"

   [b]Mass       180     # M.sin(i) = 0.56 jupiters[/b]
   Radius     56000

   InfoURL "http://vo.obspm.fr/exoplanetes/encyclo/star.php?st=Gliese+876"

   EllipticalOrbit {
      Period          0.0824
      SemiMajorAxis   0.13
      Eccentricity    0.27
      ArgOfPericenter 39
      MeanAnomaly     103
   }

   # likely to be in captured synchronous rotation
}

AltSurface "limit of knowledge" "Gliese 876/c"
{
   Texture "extrasolar-lok.*"
}


"b" "Gliese 876"   # IL Aqr
{
   Texture "jupiterlike.*"

   [b]Mass       620     # M.sin(i) = 1.935 jupiters[/b]
   Radius     70000
   Oblateness 0.03

   InfoURL "http://vo.obspm.fr/exoplanetes/encyclo/star.php?st=Gliese+876"

   EllipticalOrbit {
      Period          0.1668
      SemiMajorAxis   0.20783
      Eccentricity    0.0249
      ArgOfPericenter 245
      MeanAnomaly     220
   }

   RotationPeriod  11 # tidal slowing significant
}

AltSurface "limit of knowledge" "Gliese 876/b"
{
   Texture "extrasolar-lok.*"
}

I also noticed that the newly discovered terrestrial world ("d"), is the same distance as "b", yet orbits in a single day, instead of a month or 2.

[hank]

then what is this?

You can specify a mass in the .ssc file (for reference purposes), but Celestia doesn't use it for anything.

I also noticed that the newly discovered terrestrial world ("d"), is the same distance as "b", yet orbits in a single day, instead of a month or 2. :?

According to the InfoURL page, the SemiMajorAxis for d should be 0.0208067, not 0.20806 as in the .ssc file.

- Hank

[PlutonianEmpire]

ah. thanks

[selden]

Note that the SMA of d has been corrected in the current version of extrasolar.ssc on SourceForge.