semiregular variable

Some are poorly studied semiregular variables, often with multiple periods, but others may simply be chaotic.

Semiregular variables may show a definite period on occasion, but also go through periods of irregular variation.

V810 Centauri is a semiregular variable.

Rho Cassiopeiae is a single star, and is categorized as a semiregular variable.

Semiregular variables are classified in several subtypes:

VY CMa is a single star categorized as a semiregular variable and has an estimated period of 2,000 days.

Semiregular variables may show a definite period on occasion, but more often show less well-defined variations that can sometimes be resolved into multiple periods.

Beta Gruis is a type semiregular variable (SRb) star that varies in magnitude by about 0.4.

BL Crucis is a red giant and a semiregular variable in the constellation of Crux.

It is a representative of the semiregular variables, whose periods of variation are subject to more irregularities than those of Mira variable red supergiants.

The outer envelope of this star is undergoing a type of pulsation that occurs in a class of variable stars known as semiregular variables and its brightness varies from magnitude +3.32 to +3.40.

While most supergiants show some degree of photometric variability, such as Alpha Cygni variables, semiregular variables, and irregular variables, there are certain well defined types of variables amongst the supergiants.

In the Population II stars this irregularity gradually increases from the low period W Virginis variables through the RV Tauri variables into the regime of the semiregular variables.

R and S Leonis Minoris are long-period Mira variables, while U Leonis Minoris is a semiregular variable; all three are red giants of spectral types M6.5e-M9.0e, M5e and M6 respectively.

These giant stars are observed to undergo pulsations ranging from weak irregularity, when one can still define an average cycling time or period, (as in most RV Tauri stars and Semiregular variables) to the near absence of repetitiveness in the Irregular variables.