L1527 IRS System (2012) - Youngest still-forming solar system found yet, about 300,000 years old. 450 light years away in the Taurus Cloud and is one of the closest examples of the earliest stages of star formation. Has one fifth the Sun's mass, but is believed to be able to grow to about the same mass as the Sun. Has enough material in its disk for seven Jupiters.
UX Tauri System (2007) - Of of the two youngest stars detected with evidence for a planet-forming circumstellar disk. Ring-like gaps where planets may be forming were detected, spanning from Mercury to Neptune like distances. Large and non-spherical dust particles were detected, evidence of planetary formation.
LkCa 15 System (2007) - One of the two youngest stars (about a million years old) detected with evidence for a planet-forming circumstellar disk, located 450 ly away. Has an outer dust disk (which would envelop the Solar System) and a thin inner dust disk (which would fit inside Mercury's orbit). The inner disk is somewhat lopsided. Planet b was later detected, the youngest and first direct photograph of a protoplanet. It is a giant planet orbiting at Uranus-like distances and appears as a blue dot. It is about 1,000C and surrounded by a red structure about 500C, which could be material colliding into the protoplanet or being ejected from it. Its mass, and planetary status, still needs to be determined. Hydrogen was found to be heated to 10,000C, which implies that it is falling onto the surface of a planet no more than 10 times Jupiter's mass. Two other unconfirmed planets show no signs of glowing hydrogen, so are most likely completely formed, or partially masked by intervening clouds of dust. One of these planets is slightly further out than the confirmed one.