VLT ultracam observations of PG1336018

1
VLT ultracam observations of PG1336-018

• A subdwarf B star in a 0.1d eclipsing binary
• Multiperiodic pulsations with periods about 3
  minutes
• M dwarf companion shows reflection effect

Ultracam (top right) is a 3-channel photometer,
used for measuring starlight in three different
colours (ultraviolet, green and red) at very high
speeds. In 2005 May it was mounted on one unit of
the ESO Very Large Telescope at Paranal, Chile
(top left). Each VLT unit is a telescope with a
diameter of 8m.
0.1d
Pulsations were observed through eclipse in order
to measure pulsation geometry. Knowing this
geometry allows us to deduce internal structure
of the star asteroseismology