GK Persei

It was discovered by Thomas David Anderson, an Edinburgh clergyman, at 02:40 UT on 22 February 1901 when it was at magnitude 2.7.

Since about 1980, these outbursts have become quite regular, typically lasting about two months and occurring about every three years.

Surrounding GK Persei is the Firework Nebula, a nova remnant first detected in 1902 consisting of an expanding cloud of gas and dust bubbles moving up to 1200 km/s.

The Hubble Space Telescope has used a different method to derive the distance to GK Persei using nebular expansion velocity and compares that with its own astrometric parallax calculation.

[13] Novae consist of a main-sequence to giant star that accretes mass onto a white dwarf.

The light curve of GK Persei, plotted from AAVSO data. The main plot shows the major outburst in 1901. Subplot A shows the minor outbursts which have been occurring about every 3 years since around 1980. Subplot B shows the outburst that occurred in 2018, on an expanded scale.