ALMA's image of the HL Tauri disc has been big news in astronomy.  But let's take a step back and look at HL Tauri's interesting neighbor, XZ Tauri.  The Hubble Space Telescope got into the act yesterday by releasing this new image of Taurus with both XZ and HL Tauri visible.  In the Hubble image, XZ Tauri is the bright star surrounded by reddish colored gas and HL Tauri is the blue "cloud" next to it.  The actual star and disc captured in the ALMA image is embedded in the gas so all we see is a brightly glowing cloud.  

There are many other interesting objects in this image including Harbig Haro (HH) objects, which are areas of nebulosity associated with jets from young stars. V1213 Tauri (lower right) is another star shrouded in dust with jets emanating from its poles that are colliding with the interstellar medium.

But back to XZ Tauri.  It was once thought to be a binary system, however, one of the stars is now believed to be a binary as well, making it a triple star system.  There is also evidence that suggests there is a protostellar disc.  In reviewing the observing proposals for ALMA, there is a high-priority proposal from 2011 that aims to use ALMA's resolving power to investigate binary star systems in Taurus.  I suspect that in the future, we're going to get a first glimpse of how a multiple star system looks and what the planet forming disc looks like in such an interesting place.  Don't expect Tatooine to be found there though (it is in a binary star system).

2 Comments