Comment 2 for bug 1271270

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Ariane Stevens (sjstar) wrote :

I would not call this a bug, it is just a limitation.

Radial velocities added to the database would have to be added before it could apply to all stars.

As the timeframe changes, the positions, magnitudes, distances, parallaxes and proper motions would all change based on the date. The motion also would also accelerate or slow down as they respectively approach us or recede from us.

However, this would not change binary stars. To fix this you would need the mean proper motions, and the mean radial velocity (the components oscillate above and below the mean velocity, termed /gamma/ as seen is spectroscopic binaries. It could be estimated based on the eccentricity, and even the inclination as well. This would not be simple. Some average value would suffice as general use of the software.

Other programs, like Voyage 4 apply the radial velocity so you can see all these changes, but the binaries still fly apart moving off in their programmed proper motions.
"
Radial velocities for all the Hipparcos stars would use either "Radial velocities for XHIP catalogue (de Bruijne+, 2012)" or "Extended Hipparcos Compilation (XHIP)" (Anderson+, 2012) "Another useful one is General Catalog of mean radial velocities." (Barbier-Brossat+, 2000) Stand for most is the "Pulkovo radial velocities for 35493 HIP stars" (Gontcharov, 2006). This might suffice!)

For the more distant stars, these effects are trivial, so applying this to down to 9th and 10th magnitude would be sufficient. Applying it to all star with 200 pc, would be desirable, as the +/-99999 years, makes little difference to stellar positions.

All data would be available using the CDS Vizier.

Thankx, Ari