Cygnus is a constellation that forms a prominent cross shape in the northern sky. The brightest star in Cygnus, Deneb, marks the top of the cross.

Is there anything else you can tell me about what you're looking for? For example:

* What time of year are you looking at the sky? Cygnus is most prominent in the summer months of the Northern Hemisphere.

* What part of the sky are you looking at? The "cross" shape of Cygnus is pretty distinct.

* Are there any other stars or objects you can see near it?

With more information, I can help you identify the constellation you're thinking of.