26 Andromedae, abbreviated 26 And, is a binary star system in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

Andromeda. ''26 Andromedae'' is the Flamsteed designation. It has a combined apparent visual magnitude of 6.10, which is near the lower limit of visibility to the naked eye. The distance to this system can be estimated from its annual parallax shift of , which yields a distance of about 600

light year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distance, astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by t ...

s. At that distance, the visual magnitude of the stars is diminished from an

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

of 0.04 due to interstellar dust. The system is moving further from the Earth with a heliocentric radial velocity of +3.3 km/s. The magnitude 6.11 primary, component A, is a B-type main-sequence star with a

stellar classification In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction gratin ...

of B8 V. The star has 3.54 times the mass of the Sun and 3.76 times the Sun's radius. It is around 95 million years old and is spinning with a

projected rotational velocity Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface. The rotation of a star produces an equatorial bu ...

of 18 km/s. 26 And is radiating 219 times the Sun's luminosity from its

photosphere The photosphere is a star's outer shell from which light is radiated. It extends into a star's surface until the plasma becomes opaque, equivalent to an optical depth of approximately , or equivalently, a depth from which 50% of light will esc ...

at an

effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...

of 11,939 K. It displays an infrared excess that suggests a circumstellar

debris disk A debris disk (American English), or debris disc ( Commonwealth English), is a circumstellar disk of dust and debris in orbit around a star. Sometimes these disks contain prominent rings, as seen in the image of Fomalhaut on the right. Debris ...

orbiting at a distance of from the star with a temperature of 75 K. The fainter secondary, component B, is a magnitude 9.70 star located from the primary. It is an F-type main-sequence star with a class of F3 V that shows an unexplained long term variability. One of the components of this system displays a slight photometric variation with a period of 3.16 days. This may be caused by pulsation or an ellipsoidal variation. This system's X-ray emission hasn't been detected yet, with an upper limit of L_x < 29.79 erg/s.

References

External links

Image 26 Andromedae
{{DEFAULTSORT:26 Andromedae B-type main-sequence stars F-type main-sequence stars Spectroscopic binaries Suspected variables Circumstellar disks Andromeda (constellation) Durchmusterung objects Andromedae, 26 001438 001501 0070