LkCa 15 is a T Tauri

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 ...

in the Taurus Molecular Cloud. These types of stars are relatively young

pre-main-sequence A pre-main-sequence star (also known as a PMS star and PMS object) is a star in the stage when it has not yet reached the main sequence. Earlier in its life, the object is a protostar that grows by acquiring mass from its surrounding envelope of ...

stars that show irregular variations in brightness. It has a mass that is about 97% of the Sun, 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 4370 K, and is slightly cooler than the Sun. Its

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...

is 11.91, meaning it is not visible to the naked eye.

Planetary system

LkCa 15 is surrounded by a protoplanetary disk, typical of many T Tauri stars. The disk around the star is about 55 times more massive than Jupiter, and consists of three major belts (components). Small changes in the observed brightness of the disk may be due to a planetary companion; the star was believed to have a protoplanetary object or

exoplanet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

orbiting it, known as LkCa 15 b This name stems from an older survey. Later, the existence of up to three planets was suspected. The planets' existence was refuted in 2019 as higher resolution imaging became available. LkCa 15 b is a candidate protoplanetary object in orbit around LkCa 15, a star in the Taurus-Auriga Star Forming Region. Its potential discovery was effected by direct imaging techniques using the Keck II telescope in 2011 by Adam Kraus and Michael Ireland. A 2015 study of observations from the Magellan Telescopes and the Large Binocular Telescope argued that the

planet A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a you ...

is forming through

accretion Accretion may refer to: Science * Accretion (astrophysics), the formation of planets and other bodies by collection of material through gravity * Accretion (meteorology), the process by which water vapor in clouds forms water droplets around nucl ...

. It would be the first observed

seen in the process of active accretion. The planet’s existence was refuted in 2019 as higher resolution imaging became available.

References

{{DEFAULTSORT:LkCa 15 Pre-main-sequence stars K-type main-sequence stars T Tauri stars Tauri, V1079 IRAS catalogue objects J04391779+2221034 Hypothetical planetary systems Circumstellar disks Taurus (constellation)