South-eastern sky above the tree line just now, NE Cape Cod, I saw a very bright, twinkling "star" I live in New England, Cape Cod to be exact. 

I saw a very bright, twinkling object. I watched it for several minutes and it never moved. It was in the east just above the tree line, what might it be?
I just did the following:


opened in-the-sky.org, 
manually chose the location New Bedford, MA (close to Cape Cod) because I'm somewhere else (you wouldn't have to do that) 
selected planetarium 


and looked in the southeast and found that the brightest star in the sky Sirius is currently only 20 degrees above the horizon.  At that low altitude, and being a star (not a planet) it would definitely be bright and twinkle, and not appear to move like a plane.

It is rising, and moving diagonally to the right and up. Check back in an hour or so to confirm that if you are interested, or check in the next several days to confirm it's in the almost the same place each night.