Astronomy

72 ASTRONOMY • APRIL 2018

1. CLOUD WITHIN A CLOUD
   Sharpless 2–173 is an emission nebula
   in the constellation Cassiopeia the
   Queen. Astronomers think the bright
   blue star below the main nebula
   provides the energy to ionize the
   gas and make it glow. The red star
   just touching the nebula to the left
   is HD 1613, a cool (spectral class M2)
   giant. • Brian Peterson


2. SETTING A HIGH BAR
   Barred spiral galaxy M95 lies in the
   constellation Leo the Lion. M95 is part
   of the Leo Trio, along with M96 and
   M105. It lies some 38 million light-years
   away and sports a diameter of 75,000
   light-years. • Madhup Rathi

READER

GALLERY

1

2