W Hydrae


W Hydrae is a Mira-type variable star in the constellation Hydra.
The star is nearly located within the Solar neighborhood, at 320 light years from the Solar System. It has a visual apparent magnitude range of 5.6 to 10. In the near-infrared J band it has a magnitude of -1.7, is the 7th brightest star in the night sky, and is even brighter than Sirius.

Water masers and dust

The star also shows signs of intense water emissions, indicative of the presence of a wide disk of dust and water vapour. Such emissions cover a zone spanning between 10.7 Astronomical Units and 1.2 parsecs.