If your absolute favorite sports figure or movie star died before you were even born, it's going to be impossible for you to see them and get their autograph. However, that doesn't mean that you can't have an autograph. If that person signed many autographs in their life, that means that it is likely that there will be autographs you can purchase. It might not be personalized to you, but it will still be your favorite's signature. But, there may be some fake autographs you'll have to discern. How can you tell if the one you want to purchase is real or not?
Ask for Provenance & Documentation
One way you can tell that you are getting an authentic autograph is to ask for provenance and documentation. The provenance is the history of the autograph, meaning who had it first, who bought and sold it, and possibly even how much it sold for. There might not be one, which doesn't automatically mean it's a forged signature, but the dealer should be able to give you more info. Generally, the rarer or more valuable an autograph is, the more likely it will come with provenance and documentation. The documentation can include paperwork from an authenticator stating that the autograph is real.
Check Against Known Signatures
You should also check the autograph against known signatures. More than just looking at known signatures of the person, you want to look at signatures from around the same time period. Over the years, a person's signature is going to change slightly. Your own signature is going to look different now than it might have 10 years ago. So, if you are looking to purchase something like a Katharine Hepburn autograph from 1940, you want to look for examples of her signature within a couple of years of that date. When looking for known signatures to compare to, make sure that you aren't finding an image of the autograph you are planning on buying because comparing it to itself isn't going to be all that helpful when ensuring that you are getting an authentic signature.
Being able to hold a piece of history in the form of the autograph of your favorite celebrity can be really exciting. Just make sure that the signature you are looking to purchase is the real thing. Following these recommendations will help make sure that you are dealing with a real autograph. To learn more, contact a company that provides things with vintage autographs for sale.