The star cluster embedded within NGC 7822 is called Berkeley 59, and its dominant member is a star called BD+66 1673. Despite this innocuous name, BD+66 1673 is one of the hottest stars in our astronomcial neighbourhood, with a truly scorching surface temperature of around 45,000 Kelvin (compared to our Sun’s 5800 Kelvin). In addition, it’s more 100,000 more luminous (i.e. gives out more than 100,000 times as much energy) as our Sun.

Given all this, you’d expect it to look more… well, impressive! The star is very far away though, and concealed within the fog of the surrounding nebulosity. Also, it’s giving out most of its light in the ultraviolet part of the spectrum, which I can’t detect with my camera. All these factors combine to “dim” the star’s appearance in my photo.

However! We can see evidence of BD+66 1673’s immense power all around it. NGC 7822’s dramatic pillars and ridges have been carved out by the energy from BD+66 1673, and its ultraviolet radiation is making the gas glow. So, if it weren’t for BD+66 16, NGC 7822 itself would be a lot less interesting.