Planet Forming at TW Hya?

Hubble Release:
http://hubblesite.org/newscenter/archive/releases/2013/20

Quote :

The keen vision of NASA's Hubble Space Telescope has detected a mysterious gap in a vast protoplanetary disk of gas and dust swirling around the nearby star TW Hydrae, located 176 light-years away in the constellation Hydra (the Sea Serpent). The gap's presence is best explained as due to the effects of a growing, unseen planet that is gravitationally sweeping up material and carving out a lane in the disk, like a snow plow.

There is also a PDF preprint of referred paper at HubbleSite page:
 
http://hubblesite.org/pubinfo/pdf/2013/20/pdf.pdf
 
It also mentions a very low mass for the (putative) planet, between 6 and 28 Earth masses, something like a "Neptune twin" (unless it is a symbol typo). 
 

Quote :

Based on scalings to previous hydrodynamic simulations of gap opening criteria for embedded proto-planets, we estimate that a planetary companion forming the gap could have a mass between 6-28 M⊕.

http://www.eso.org/public/news/eso1333/

A snow line has been imaged in a far-off infant planetary system for the very first time. The snow line, located in the disc around the Sun-like star TW Hydrae, promises to tell us more about the formation of planets and comets, the factors that decide their composition, and the history of the Solar System. The results are published today in Science Express