Garnet star and Elephant Trunk nebula
Imaged by Jean-Yves Beninger from Ollioules, France on 18 August 2023
When Sir William Herschel observed Mu Cephei in 1783 he described it as a most beautiful object of a very fine deep garnet colour, that's exceptionally striking when
compared to nearby white stars.
In fact, Mu Cephei is an extremely luminous red supergiant and one of the reddest known stars of all.
It may be the largest star visible to the naked eye with an estimated radius of 1.15 billion kilometres (710 million miles) or 1,650 times that of the Sun.
In astronomical terms, Mu Cephei doesn't have long to live.
It has almost certainly stopped internal hydrogen fusion, and is likely fusing helium into carbon. Whatever the current state, the Garnet star
will almost certainly go bang sometime in the "near" future and destroy itself in a massive supernova explosion.
Astro-Physics AP92, Field Flattener for 644mm focal length, f7
Rainbow Astro RST-135E mount
ZWO ASI2600MC camera with Duo band filter with bandwidth HA (15nm) and OIII (35nm)
Stack of 28 images of 5 minutes, bin 1x1