74 ASTRONOMY • JUNE 2015
A stunning
VISTA view
Amateur astronomers
know the Trifid Nebula
(M20) in Sagittarius well.
At visible wavelengths,
dark dust lanes divide the
bright star-forming region
into three distinct parts.
But this infrared image
shows the Trifid in a differ-
ent light. Captured with
the 4.1-meter Visible and
Infrared Survey Telescope
for Astronomy (VISTA) at
Paranal Observatory in
Chile, M20 glows a ghostly
blue (bottom) while more
distant objects shine
through. Astronomers
also discovered two
Cepheid variable stars in
this wide-field view. The
Trif id lies ab out 5, 20 0
light-years from Earth,
while the Cepheids are
37,000 light-years distant,
some 10,000 light-years
beyond the galaxy’s cen-
ter. ESO/VVV CONSORTIUM/D. MINNITIBREAK
THROUGH