A T N F    D a i l y    A s t r o n o m y    P i c t u r e

6th of March 2015
The first "water fountain" in a planetary nebula
by José-Francisco Gómez (Instituto de Astrofísica de Andalucía, CSIC, Granada, Spain)
Gómez et al. (2015) have used the Australia Telescope Compact Array (ATCA) to map the water maser emission in IRAS 15103-5754, an object that has just become a planetary nebula. Its water maser emission spreads over a large velocity range (75 km/s) and most of it traces a collimated jet aligned with the infrared nebula. This is characteristic of a special type of evolved stars called "water fountains". IRAS 15103-5754 is the first known case of a water fountain that is already a planetary nebula (all others are in previous evolutionary stages. However, the velocity pattern of masers is different from that in other water fountains: it is consistent with a short-lived, explosive event, rather than with a steady jet. This suggests a fundamental change in the characteristics of mass-loss as a star enters the planetary nebula phase.

The figure represents the maser components (crosses) superposed on a mid-infrared image (at 12.81 microns) obtained with the Very Large Telescope (VLT) by Lagadec et al. (2011).

Credits: 2015. The American Astronomical Society.

<<   |   archive   |   about   |   today   *   ATNF   |   Parkes   |   ATCA   |   Mopra   |   VLBI   |   ASKAP   |   >>