RR Coronae Borealis (RR CrB, HD 140297, HIP 76844) is a M3-type semiregular

variable Variable may refer to: * Variable (computer science), a symbolic name associated with a value and whose associated value may be changed * Variable (mathematics), a symbol that represents a quantity in a mathematical expression, as used in many ...

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

located in the constellation Corona Borealis with a

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...

of 2.93mas being a distance of . It varies between magnitudes 7.3 and 8.2 over 60.8 days. Located around 1228 light-years distant, it shines with a

luminosity Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object over time. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a st ...

approximately 2180 times that of the Sun and has a surface temperature of 3309 K.

References

Corona Borealis Semiregular variable stars M-type giants Coronae Borealis, RR 140297 076844 Durchmusterung objects {{var-star-stub