Agena distance

eburacum45 · Post #1by **eburacum45** » 16.11.2004, 19:58

I don't know if this is the right forum for this, but some new work seems to have found a distance error in Hipparchos for the major star Agena;
http://kencroswell.com/BetaCentauri.html

the new distance should be 'about' 330 light years, as opposed to 525 as shown in Celestia. Since binary star data is being included in the next version perhaps this might be taken into account at some point.

Of course it would be nice to have a more accurate distance than 'about' 330 ly...

Post #2by **selden** » 16.11.2004, 20:10

Tch.
You didn't read the abstract, did you?

The "about 330ly" is the result of Ken Croswell's translation from pc to ly. The measured distance is 102.3 pc, a quite respectable precision.

eburacum45 · Post #3by **eburacum45** » 16.11.2004, 20:22

Excellent!

Is it worth pointing out errors like this, by the way?
steve

Post #4by **selden** » 16.11.2004, 20:27

Post #5by **selden** » 17.11.2004, 00:31

Here's an STC file for BET Cen that Grant provided. He tells me that he'll be correcting the distance in stars.dat

Code: Select all

Barycenter "Agena:Hadar:BET Cen"
{
 RA 210.95601898
 Dec -60.3729784
 Distance 333.5
}

68702 "Agena A:Hadar A:BET Cen A"
{
 OrbitBarycenter "Agena"
 SpectralType "B1III"
 AppMag 1.20

 EllipticalOrbit {
  Period          1.0231
  SemiMajorAxis   1.29   # mass ratio 9.1:9.1
  Eccentricity    0.821
  Inclination 112.6
  AscendingNode   133.7
  ArgOfPericenter 233.5
  MeanAnomaly     306.9
 }
}

"Agena B:Hadar B:BET Cen B"
{
 OrbitBarycenter "Agena"
 SpectralType "B2III"
 AppMag 1.35

 EllipticalOrbit {
  Period          1.0231
  SemiMajorAxis   1.29   # mass ratio 9.1:9.1
  Eccentricity    0.821
  Inclination 112.6
  AscendingNode   133.7
  ArgOfPericenter 53.5
  MeanAnomaly     306.9
 }
}

symaski62 · Post #6by **symaski62** » 17.11.2004, 01:03

cel://Follow/Agena/2004-11-17T00:41:01.82732?x=AAC4nxfd+phcarry/////w&y=AADkLx6iNLAq8DLq/////w&z=AADo/KzUF6hv5yAS&ow=-0.269213&ox=-0.071257&oy=0.885697&oz=0.371467&select=Agena&fov=16.410744&ts=1.000000<d=0&rf=102691&lm=-209848811

:?:

520 ly ou 330 ly

HIP 68702 et HR 5267

bye

Post #7by **selden** » 17.11.2004, 01:15

520 ly ou 330 ly

333.5 ly

lisez ceci, s'il vous plait:
http://xxx.lanl.gov/abs/astro-ph/0411054

symaski62 · Post #8by **symaski62** » 17.11.2004, 01:26

selden wrote:
:?: 520 ly ou 330 ly

333.5 ly

lisez ceci, s'il vous plait:
http://xxx.lanl.gov/abs/astro-ph/0411054

yes, 0411054.pdf (pages 8)

:wink: bye selden