You left out the most important fact - did they have a will. Since you did not mention it, I will assume they did not. You also did not mention where they live. Each state is different, so for purposes of crafting a general answer, I will assume they live in CA.
Generally the assets will be distributed based on Probate Code section 6400-6414.
A. If the decedent was not married, the estate is distributed as follows: 1. To the decedent's children, who take in equal shares if they are in the same generation. 2. If there are no children or other issue (issue is the legal term for children, grandchildren, great-grandchildren, etc.) living, the estate goes to the decedent's parents. 3. If there are no parents living, the estate is distributed to the "issue of the parents." If the decedent had brothers or sisters, they will inherit the estate. 4. If there are no brothers or sisters, the decedent's grandparents will inherit the estate. 5. If there are no grandparents, then the "issue of the grandparents" will inherit the estate. This could include the decedent's aunts and uncles, or if there aren't any aunts and uncles, the decedent's cousins. 6. If there are no cousins, Probate Code section 6402 provides that the estate will be distributed to "next of kin in equal degree," generally meaning more distant cousins.
B. If the decedent was married, the first question is whether the decedent owned community property, separate property, or a combination of the two. Community property is generally defined as the assets acquired during marriage from earnings or salary. Separate property is generally defined as assets brought into the marriage when the decedent got married, inheritances to the decedent, or gifts to the decedent. However, California case law provides many exceptions to these definitions, and assets can change from community to separate property, or from separate to community, by combining assets, by improving separate property with community property, or by written agreement of the spouses, for example.
1. The decedent's community property goes to the surviving spouse, who may have to file a spousal property petition to establish ownership. 2. The decedent's separate property is distributed as follows: a. The surviving spouse receives all of the separate property if the decedent is not survived by issue, parents, brothers, sisters, or children of a deceased brother or sister. b. The surviving spouse receives one-half of the separate property if the decedent had only one child, or issue of a deceased child. c. The surviving spouse receives one-half of the separate property if the decedent left no issue, but left parent(s) or their issue. d. The surviving spouse receives only one-third of the separate property if the decedent left more than one child. e. The surviving spouse receives only one-third of the separate property if the decedent left one child and the issue of one or more deceased children. f. The surviving spouse receives only one-third of the separate property if the decedent left the issue of two or more deceased children.
The previous answer begs the question you asked. If California law applies and neither your aunt nor your uncle had a will, then the property passes by intestate succession. If there are no children, then California probate code section 6402.5(a) would apply as to real property (e.g., a house) (since your aunt passed away more than 5 years after your uncle, section 6402.5(b) would NOT apply as to personal property.
Your uncle's share of the real property would be distributed to his nearest surviving relatives (his surviving siblings and the "issue" of deceased siblings) and aunt's share of the real property would be distributed to her nearest surviving relatives (her surviving siblings and the "issue" of deceased siblings).
The personal property would all be distributed to your aunt's nearest surviving relatives (again, surviving siblings and "issue" of deceased siblings).
If the estate is worth less than $100,000 and it is in California, you can use a "small estates affidavit" to distribute the property (if there is real property involved, though, there are a few special considerations that need to be taken into account). Even if the estate is worth less than $100K, it might be easier to do a probate if there are a number of siblings & issue of deceased siblings to contend with or if there are a number of debts.
This information is not intended to substitute for professional legal advice and does not create an attorney-client relationship. You should accept legal advice only from a licensed legal professional with whom you have an attorney-client relationship.