tilly you said: "Jupiter, and Venus will be along later. "
I said: "Venus is visible to about 18:30. Jupiter and Saturn later. " - ie Venus has already set and both Jupiter and Saturn occur after that.
Thanks all for your suggestions which were all wrong.
Jupiter sets soon after sunset so is nowhere near 50 degrees elevation.
Sirius is not in the west at 8pm.
After a lot of studying, I believe that the answer is Vega.
Happy stargazing.