I had an idea of using a specific type of data in a specific research area (sorry, I realize this sounds vague). No one has used this type of data in this area before. I shared the idea with my advisor. Recently I noticed the advisor and another student published a paper based on my idea. I think it is not fair. What do I do?
Edit: Thank you all for the comments and answers.
To clarify a couple of things: it wasn't just a fleeting conversation or group brainstorming. I came up with the idea myself, did initial work, and shared it with the advisor. I would expect to be at least told they wanted to work on this even if they were to conduct an independent analysis. I do not think the time frame and other factors would allow forgetting where the idea came from. The group works on several topics and my idea was more like a side line project. There is a lot of publications coming from these main topics, so it's not like this specific paper would be crucial for future funding.
I think the worst in the whole situation is that now I distrust my advisor.