R Cassiopeiae is a

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as e ...

in the northern constellation of Cassiopeia. It is located approximately 574 light years distant from the Sun, but is drifting closer with a radial velocity of −23 km/s. This is a pulsating Mira-type

with a brightness varies from magnitude +4.4 down to +13.5 with a period of 433.6 days. At its maximum, R Cassiopeiae is visible to the naked eye as a faint, red-hued star. This aging red giant star has a stellar classification that varies from M6e to M10e, where the 'e' suffix indicates emission features in the

spectrum A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors ...

. Currently on the asymptotic giant branch, it has 59% of the mass of the Sun with an oxygen rich chemical abundance. Having exhausted the supply of hydrogen at its

core Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (manufacturing), used in casting and molding * Core (optical fiber), the signal-carrying portion of an optical fiber * Core, the centra ...

, the star has expanded to 263–310 times the Sun's radius. On average, the star is radiating 3,837 times the

luminosity of the Sun The solar luminosity (), is a unit of radiant flux ( power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun. One nominal ...

from its swollen photosphere with an effective temperature ranging around 2,812 K. It is losing mass at the rate of and is surrounded by a dusty circumstellar shell that extends out to .

References

{{Stars of Cassiopeia M-type giants Mira variables Emission-line stars Cassiopeia (constellation) Durchmusterung objects 224490 118188 9066 Cassiopeiae, R

See also

References