NGC 6826 (also known as Caldwell 15) is a planetary nebula in the constellation Cygnus. It is commonly known as the "flickering planetary planet", although many other nebulae exhibit this "blinking, it is about 2200 light-years away from Earth." This nebula is 1.3 degrees east of Theta Cygni. and has an apparent magnitude of 8.8.It was discovered in 1793 by William Herschel.
It is the final phase of a star similar to the Sun, a very short phase compared to the age of the star (approximately 10 billion years). It is marked by two sets of "red" flyers that are horizontally in the image. It is believed that the faint "green" green surrounding the eye is the gas that makes up almost half the mass of the star for most of its life.
Characteristic:
This planetary nebula receives its name by an optical illusion, the nebula seems to vanish and then appears again, so it resembles the blinking of an eye, this is the most pronounced effect observed with the deviated vision technique.
A distinctive feature of this nebula are the two bright patches on either side, which are known as FLIERs, or Fast Low-Ionization Emission Regions. They appear to be relatively young, moving outwards at supersonic speeds.
According to Bruce Balick (University of Washington), "some of their observed characteristics suggest that they are like sparks flung outward from the central star late in the very recent past (a thousand years ago).
Yet their shapes ... seem to suggest that they are stationary, and that material ejected from the star flows past them, scraping gas from their surfaces.
- Alt. Designations: NGC 6826
- Object Type: planetary nebula
- Constellation: Cygnus
- Distance: 2 kly
- Right Ascension: 19h 44m 48.2s
- Declination: +50° 31´ 32"
- Visual Magnitude: 8.8
- Apparent Dimension: 0.6´ Dia.
- Best Month To View: Jul
With 9x63 binoculars and a magnitude close to 6 is seen as an object of stellar appearance, but very bright and with the technique of deviated vision, you can see a slight flicker, also seen as a star-shaped object. With more increases (15-20x) can be seen as an unfocused star and little else.
The observation of the Hubble telescope was taken on January 27, 1996 with the planetary camera and wide field 2.
https://josevicentediaz.com/2016/01/09/el-ojo-que-parpadea-ngc-6826/