Robert Tulip

2009-Jul-05, 01:53 AM

How do the direction and speed of proper motion of Canopus and Vega plot on to the following star maps?

Vega: http://commons.wikimedia.org/wiki/File:Precession_N.gif Vega is the large star at bottom and has proper motion (μ) RA: 201.03 mas/yr Dec.: 287.47 mas/yr

Canopus: http://commons.wikimedia.org/wiki/File:Precession_S.gif Canopus is the large star at upper left and has proper motion (μ) RA: 19.99 mas/yr Dec.: 23.67 mas/yr

Is this information sufficient to plot the vectors?

How do you calculate the direction and speed of right ascension and declination from these maps?

http://en.wikipedia.org/wiki/Vega#Kinematics states that the net proper motion of Vega is 327.78 mas/y, which results in angular movement of a degree every 11,000 years.

Do the numbers above indicate that the net proper motion of Canopus is about one tenth of that of Vega, resulting in angular movement for Canopus of a degree about every 125,000 years?

Just by Pythagorean formula, the figures for Vega give √(RAxRA + DecxDec) = 350 mas/y. Given the actual Vega figure of 327.78 this would result in a speed of 29 mas/y for Canopus, but I don’t know how to work it out properly or to plot the direction.

This is to assist in response to questions at ATM thread Canopus-Sol Relation.

Thanks.

Vega: http://commons.wikimedia.org/wiki/File:Precession_N.gif Vega is the large star at bottom and has proper motion (μ) RA: 201.03 mas/yr Dec.: 287.47 mas/yr

Canopus: http://commons.wikimedia.org/wiki/File:Precession_S.gif Canopus is the large star at upper left and has proper motion (μ) RA: 19.99 mas/yr Dec.: 23.67 mas/yr

Is this information sufficient to plot the vectors?

How do you calculate the direction and speed of right ascension and declination from these maps?

http://en.wikipedia.org/wiki/Vega#Kinematics states that the net proper motion of Vega is 327.78 mas/y, which results in angular movement of a degree every 11,000 years.

Do the numbers above indicate that the net proper motion of Canopus is about one tenth of that of Vega, resulting in angular movement for Canopus of a degree about every 125,000 years?

Just by Pythagorean formula, the figures for Vega give √(RAxRA + DecxDec) = 350 mas/y. Given the actual Vega figure of 327.78 this would result in a speed of 29 mas/y for Canopus, but I don’t know how to work it out properly or to plot the direction.

This is to assist in response to questions at ATM thread Canopus-Sol Relation.

Thanks.