I know that a 'sun day' is the time that a sun spot takes to orbit one time across the suns surface (25-30 days dependent on location I think) and what is actually defined as a 'sun year' is how long it takes for our solar system to orbit the galaxy.
But I would like to know how long it takes for the centre of the sun to return to its starting point, hence the caption marks marks around 'sun year'
Am I correct to think that the sun translates a very little bit because of the planets rotating around it?
Is it even measurable?
edit: by sun year i mean my definition of sun year, not the standart definition