Whatever happened to Aurora?

My local art shop has a stock of old Winsor and Newton Professional Watercolours in their old white tubes, and amongst them I saw a colour called "Aurora Yellow" - it's not on their colour charts etc but it can't  be that old (a few years) - the tube that is - so I'm wondering, when did they discontinue it and how does it differ from Cadmium Yellow Light, which contains the same pigment?