Hayden Panettiere: Remembering Star on Her 37th Birthday

Hayden Panettiere would have turned 37 today ... but sadly the celebration will be more of a remembrance.

As TMZ previously reported ... the "Nashville" star had big travel plans to be with her daughter in Germany today ... as part of a trip she told her friends she was ecstatic about.

Unfortunately, Hayden never got to make the trip.

As you know ... Hayden was found dead in a South Carolina apartment last Sunday ... in the company of her boyfriend Brian Hickerson, who was asleep in another room when his brother came in to find Hayden unresponsive on an armchair.