Is this enough info to construct a binary?

[Slartibartfast]

To a degree I had it coming. There was more than one question I asked that I could have thought through to a greater degree. I blame it on staying up way too late and the headaches I get for doing so. Well, that's my story anyway and I'm sticking to it. =)

[Slartibartfast]

Well, I've stuck a fork in Beta Centauri and called it done. I tweaked the orbit of star B so that it will start where its RA and Dec say it is. (My book has it orbiting the other pair and I'm not rewriting that much over for the sake of accuracy... the planet's gotta stay in the L4.) All my other stats are as per ajtribick's. Thank you everyone for your help and endless patience. I promise to read more. =)

[Slartibartfast]

@*&^%(@!!!! I spent the last 2+ hours reading and tweaking trying to find an answer to the following question, and I can't. So, here's what I hope is ONE LAST QUESTION:

As per previous instructions, I took the ArgOfPericenter of the star and subtracted 60 to get the LongOfPericenter for my planet that's supposed to be in the Trojan. It worked at first, until I changed the period to agree with the new orbit. (Ain't that wierd?) Now, it doesn't matter what value I give the LongOfPericenter, it won't move... and it's in the wrong place (it's 90 degrees away along the orbit instead of 60). What the????

Here's the star system:

Code: Select all

# Bet Cen AA-AB/B #VERSION 3
Barycenter "BET Cen"
{
   RA 210.955835572
   Dec -60.373041266
   Distance 353.384
}

   Barycenter "Barycenter BET Cen A"
   {
      OrbitBarycenter "BET Cen"

      EllipticalOrbit {
         Period          379.7539
         SemiMajorAxis   14.64164
         Eccentricity    0.0
         Inclination   0   
         AscendingNode   180
         ArgOfPericenter 0   
      }
   }


 
      68702 "BET Cen Aa:Hadar"
      {
      OrbitBarycenter "Barycenter BET Cen A"
      SpectralType "B1III"
      AbsMag -3.85

   EllipticalOrbit {
      Period 0.978528771
      SemiMajorAxis 1.285 # mass ratio 9.09:9.09
      Eccentricity 0.821
      Inclination 112.35
      AscendingNode 133.95
      ArgOfPericenter 233.15
      MeanAnomaly 304.23
   }     
      }

      "BET Cen AB:Agena"
      {
      OrbitBarycenter "Barycenter BET Cen A"
      SpectralType "B1III"
      AbsMag -3.70


   EllipticalOrbit {
      Period 0.978528771
      SemiMajorAxis 1.285 # mass ratio 9.09:9.09
      Eccentricity 0.821
      Inclination 112.35
      AscendingNode 133.95
      ArgOfPericenter 53.15
      MeanAnomaly 304.23
   }
      }

   "BET Cen B:Bedda"
   {
   OrbitBarycenter "BET Cen"
   SpectralType "B8V"
   AppMag 3.95 # From WDS


       EllipticalOrbit
                   {       
         Period  379.7539   
         SemiMajorAxis   137.89
         Eccentricity    0 .
         Inclination     -33.252
         AscendingNode   0
         ArgOfPericenter 96.15
         MeanAnomaly     0
       }
   }


For SemimajorAxis, Inclination and ArgOfP, I tweaked things until the star was in the same place as its RA/Dec. For its period, I used the spreadsheet (input mass of central stars and semimajoraxis.)

Here's the planet:

Code: Select all

"Hadar I" "Barycenter BET Cen A"
{
   Texture "NewHadar.*"
   
   Color [ 0.85 0.85 1.0 ]
   SpecularColor [ 0.5 0.5 0.55 ]
   SpecularPower 25.0
   HazeColor [ 1 1 1 ]
   HazeDensity 0.3
   Radius 6897.153 
   # Oblateness 0.0034
   OverlayTexture "sheliakhclouds.png"

   Atmosphere {
      Height 60
      Lower [ 0.43 0.52 0.65 ]
      Upper [ 0.26 0.47 0.84 ]
      Sky [ 0.40 0.6 1.0 ]
      Sunset [ 1.0 0.6 0.2 ]
      # Sunset [ 0.3 1.0 0.5 ]
      CloudHeight 7
      CloudSpeed 65
   }

   EllipticalOrbit {   
      Period          379.7539 #same as Bedda
      SemiMajorAxis   137.89
      Eccentricity      0
      Inclination       -33.256
      AscendingNode     0
      ArgOfPericenter 36.15 #Bedda's minus 60
           MeanLongitude   0
   }

   RotationPeriod   28.63
   Obliquity        0.45
   RotationOffset   0   

   Albedo            0.50
}


It doesn't matter if you call it ArgOfPericenter or LongOfPericenter, the same problem happens.
Why won't it sit in the Lagrange point?

[Slartibartfast]

Furthermore, if you give it the exact same orbital parameters of BET Cen B, then add or subtract (360/6) = 60 degrees from it's ArgOfPericenter (or in the case of your SSC, LongOfPericenter), that'll place the planet in the Lagrange point you wish.

The problem was that I needed to add/subtract 60 from the meananomaly (meanlongitude) not LongOfPericenter.

As for reading vs. asking. When a guy doesn't know 80% of the terms he's reading, he can spend hours (and I did) reading up on just the terminology, before he's able to make any sense of what he's actually reading... and then it can take hours more finding the problem (and it did). Is that a reasonable expenditure of time when you can ask instead? Especially when you have one last finishing touch to put on something before you're done?

It can be argued that it IS a reasonable expenditure of time... and I'd agree. I'm a great believer in Learning. But otoh, that is what teachers are for... facilitating learning. I am deeply grateful to hungry4info and ajtribick for facilitating my learning experience. May I be as good a teacher to those that come to me for help.