Joys ... sorry about your loss ... whatever your decision, remember the greated thing he gave you was in the moments you were able to spend together!

Now, the technical term is that he died "in testate" (without a will to direct the flow of his assets). I don't know if he lived in the US and if so if the state he lived in is a Community property state or a separate property state ... either way, the division of the property is all about what your "state" law has in it's probate code (if you are in the US).

Whether a person dies with a will or not, it often gets messy ... In my experience, it has more to do with unresolved emotions, someone's feelings have been hurting for a long time over something and all of a sudden the only way to deal with those feelings is about who get's what or doesn't get what. It's hard to watch, it's especially hard to watch if you are in the middle of it!

No matter what profession a person practices, most of us don't really like to think about our death and what might happen afterwards, so allow him the human factor in that.

You might be best served by contacting an Estate Planning attorney in your area - find one that will do the initial consultation for free and then get all your questions together for what you want to know about and ask him to explain what you will need to know about as well. At that point you can talk with other family members and let them know what possible alternatives are there for them. It may be that other members of your family have some financial needs, or future needs ... your sister and you could undoubtedly use the funds for such things as purchasing a home or schooling, or schooling for children (don't know your circumstances). But before you make any decisions, get informed. If you are in the US, they won't be able to close the estate for at least 9 months (and that would be a VERY quick closing).... usually the size of an estate that you are talking about will take 2-3 years or so and only after all the formalities have been met can anyone receive any real amount of money.

If your aunt and uncle were married a fairly long time it is likely that the court will consider all assets as jointly owned - there are a number of specific reasons why they might NOT do so - but in most situations these specifics won't come into play ... if that is the case, that all jointly owned assets will have to be reviewed as to how title was held at the time of his death ... it all gets a bit complicated ... and that's why you really should consult with an attorney about this for those types of legalities ... it may end up costing you a couple of hundred - to a couple of thousand dollars (depending where you are) for him to research all of the details, but it will be money well spent in understanding exactly the nature of the situation.

So, what I'm saying, you have time to look at your options, explore them a bit and then (hopefully) when everyone is in a clearer frame of mind, make your decision. Hope you find this helpful.

P.S. Feel free to PM me if I can answer any specific questions you may have (I'm NOT an attorney, but have worked as an Estate Planning Legal Assistant for many years - though I've been away from it for the last 18 months or so).