Calculating velocity of a knot in Cas A supernova remnant

[maverick60]

Supernova Remnant Help!

Hi guys,

Im just about to finish up my project work for my thesis which is on Cas A. I have calculate the distance between my knot and old knot from a previous experiment in arcsecs. I now need to find the velocity of my knot. Any ideas on how to calculate it?? I know i need to divide the distance by the number of years but I don't know what units.

Cheers,
Fran.

 

[Chronos]

Too vague, what 'knots' are you referring to? Angular separation tells you next to nothing about distance. Most scientists rely on redshift for extragalactic distances. Intergalactic distances are usually calibrated using Cepheids or tipping magnitudes.

 

[maverick60]

its cool i managed to work it out thanks.