Not a lot of choice here. Technically, 75 Sigma would be the choice for 1950 era dates and 69 Upsilon for 2000. But, if you want bright and well-known, Castor is not that far away and could be used.

69Upsilon GEM
Birthday from Jack’s initial research: July 14
Magnitude: 4.1
Spectrum/Star type: Red Giant
Distance in Light Years: 240
Diameter compared to Sun: 30
Luminosity compared to Sun: 115
Date best observed: Feb 28
Additional information: A double star. Upsilon is dimmer than both Castor and Pollux, but in reality is much larger!

75Sigma GEM
Birthday from Jack’s initial research: July 16
Magnitude: 4.3, variable
Spectrum/Star type: Orange Giant
Distance in Light Years: 120
Diameter compared to Sun: 15
Luminosity compared to Sun: 80
Date best observed: Mar 2
Additional information: Spectroscopic Binary. Sigma is just above Pollux