https://apod.nasa.gov/apod/ap240430.html
> The star system GK Per is known to be associated with only two of the three nebulas pictured. At 1500 light years distant, Nova Persei 1901 (GK Persei) was the second closest nova yet recorded. At the very center is a white dwarf star, the surviving core of a former Sun-like star. It is surrounded by the circular Firework nebula, gas that was ejected by a thermonuclear explosion on the white dwarf’s surface — a nova — as recorded in 1901. The red glowing gas surrounding the Firework nebula is the atmosphere that used to surround the central star. This gas was expelled before the nova and appears as a diffuse planetary nebula. The faint gray gas running across is interstellar cirrus that seems to be just passing through coincidently. In 1901, GK Per’s nova became brighter than Betelgeuse. Similarly, star system T CrB is expected to erupt in a nova later this year, but we don’t know exactly when nor how bright it will become.
https://apod.nasa.gov/apod/ap240424.html
> Dragon’s Egg. In the middle of emission nebula NGC 6164 is an unusually massive star. The central star has been compared to an oyster’s pearl and an egg protected by the mythical sky dragons of Ara. The star, visible in the center of the featured image and catalogued as HD 148937, is so hot that the ultraviolet light it emits heats up gas that surrounds it. That gas was likely thrown off from the star previously, possibly the result of a gravitational interaction with a looping stellar companion. Expelled material might have been channelled by the magnetic field of the massive star, in all creating the symmetric shape of the bipolar nebula. NGC 6164 spans about four light years and is located about 3,600 light years away toward the southern constellation Norma.
