VFTS 352 is a contact binary system in the Large Magellanic Cloud. Both stars in the system are O-type deep blue stars, roughly 7 times larger than the Sun. While VFTS 3522 is larger and more massive, both stars are incredibly similar. Both stars are tidally locked. The stars may end up creating a rapidly spinning single star in the future, but we may never know.
Astronomical data
VFTS 3521
Radius (in Solar Radii): 7.22 R☉
Diameter (in Kilometers): 10,050,240 km
Mass (in Solar Masses): 28.63 M☉
Distance (in Light Years): 164,000 ly
Spectral type: O4.5 V(n)((fc)):z: (Deep Blue)
VFTS 3522
Radius (in Solar Radii): 7.25 R☉
Diameter (in Kilometers): 10,092,000 km
Mass (in Solar Masses): 28.85 M☉
Spectral type: O5.5 V(n)((fc)):z: (Deep Blue)