Please say hello to the planetary nebula Purgathofer-Weinberger 1 (PuWe 1). This giant, circular, low surface brightness nebula, located in the constellation of Lynx, is one of the largest planetary nebulae in our skies, and was discovered in 1980 by A. Purgathofer and R. Weinberger while they were searching Palomar sky survey (POSS E) plates. Their published paper on this discovery can be found
here.
The central star is thought to be the white dwarf WD0615+556, the blue member of a red/blue optical double star; you can see them both at the centre of my image above.
With the light domes of Osaka to the south, Kyoto to the west, and Otsu to the east, 100 hours of data does not go far in these Bortle 5 skies. PuWe 1 is only faintly visible in a 6 minute Ha sub, and nothing is visibly in an OIII sub of the same duration. Purgathofer and Weinberger estimate its surface brightnesses to be 23.7 mag/arc-sec² and 26.3 mag/arc-sec² respectively, so we're talking faint! Its distance from earth is similar to that of the Helix Nebula, and based on this and its large diameter of around 1,200 arc-seconds, it is, quote, "a remarkably old nebula".
Imaged over six months from November 2019 to April 2020, PuWe 1 is presented here as an Ha/OIII/OIII combination.
Other IDs:Purgathofer-Weinberger 1;
Gaia DR2 997854527884948992;
PK 158+17 1;
PN G158.9+17.8;
PN PuWe 1;
WD 0615+556;
1SWASP J061934.22+553642.9;
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