Data from the Hubble Space Telescope reveal that the nebula Hen 3-1357 (aka the Stingray Nebula) has faded dramatically over the past two decades. These two strikingly different images of the nebula were captured 20 years apart. The image on the left was taken in March, 1996, and shows the nebula’s central star in the final stages of its life. The gas being puffed off by the dying star is much brighter than the gas photographed in January, 2016. It’s very rare to see a nebula change so quickly.
Image Credits: NASA / ESA / B. Balick (University of Washington), M. Guerrero (Instituto de Astrofísica de Andalucía), and G. Ramos-Larios (Universidad de Guadalajara)
The Stingray nebula (Hen-1357) is the youngest known planetary nebula. This Hubble image (click to embiggen) captures the bright central star is in the middle of the green ring of gas. A companion star is above it at 10 o’clock. A green spur of gas forms a faint bridge to the companion star as a result of gravitational attraction. There’s also a ring of green gas surrounding the central star and bubbles of gas at the lower left and upper right of the ring. The wind of stellar material propelled by radiation from the hot central star has created enough pressure to blow out holes in the ends of the bubbles, allowing gas to escape. The bright red, curved lines of gas are heated by the collision of the central star’s wind hitting the bubbles’ walls. The nebula is about 130 times the diameter of our Solar System. However, since it’s 18,000 light-years away, it appears only as big as a dime viewed a mile away. The colors in this picture are actual colors emitted by nitrogen (red), oxygen (green), and hydrogen (blue).
The Stingray is located in the southern constellation Ara (the Altar). As to why it’s called the Stingray … Beats me. I doesn’t look much like an old Corvette.