Mu Cephei, referred to as the "garnet star" by Herschel in 1783, is thought to be the largest star visible to the naked eye. It is a red supergiant, spectral class M2 Ia, 15 times more massive than the Sun, but 1260-1650 times larger in diameter, and 2-4 billion times more voluminous than the Sun. If the star were placed into the Solar System its surface would extend between the orbits of Jupiter and Saturn. The star is known to be a semi-regular variable with apparent magnitude range 3.4 - 5.1, and a period around 2.5 years. It completed hydrogen to helium fusion in its core, and is presently fusing helium into carbon. In the relatively near future, when it has converted its elements into iron, nuclear fusion will stop, and the star will undergo gravitational collapse resulting in a massive supernova explosion. Depending on the method used, distance estimates for the Garnet Star vary widely between 1,200 and 32,000 LY, but the "maximum likelihood estimate" of the distance is given by Famaey et al. as 1,870 ± 323 LY.

This is a part of the star field image to be combined with an IC 1396 image in Ha. But, to me it looks pretty in its own right.

Image details: -TSAPO65Q astrograph (65x420 mm) -Canon T3i modified camera, Astronomik CLS-CCD filter -Celestron AVX mount, Orion 60mm F4 SSAG Pro autoguider -18 x 240 sec subs, ISO 1600, 30 dark, 30 bias frames, 2x drizzle, 25% linear crop -Limiting magnitude ~17.5