A Star and a Nebula


A cosmic coupleThat’s the star Hen 2-427 (aka WR 124) at the center of this picture. It’s surrounded by the nebula M1-67. They’re found in the constellation of Sagittarius about 15,000 light-years away. The star shines brightly at the very center of these hot clumps of surrounding gas that it’s ejecting into space at over 150,000 km per hour.

Hen 2-427 is a Wolf–Rayet star. Named after the astronomers Charles Wolf and Georges Rayet, Wolf–Rayet stars are super-hot and characterized by a fierce ejection of mass. In this case, that results in the nebula M1-67 which is estimated to be less than 10,000 years old, a newbie in astronomical terms,

Image Credit: ESA

NGC 2022


NGC 2022 is a planetary nebula in the constellation Orion. In early telescopes (and in today’s medium-sized amateur telescopes) such nebulae look like small grayish patches of light. Since they don’t look like stars, but a bit like the gas giant planets, early astronomers tagged them as “planetary nebula,” and the name has stuck.

When stars like the Sun grow old, they expand into red giants. They then begin to lose their outer layers into space, forming a shell of gas. As the evolving star’s core shrinks and grows hotter, it emits ultraviolet light that causes the expelled gases to glow.

Image Credit: NASA / ESA