TZ Arietis (also known as Gliese 83.1, GJ 9066, or L 1159-16) is a

red dwarf A red dwarf is the smallest kind of star on the main sequence. Red dwarfs are by far the most common type of fusing star in the Milky Way, at least in the neighborhood of the Sun. However, due to their low luminosity, individual red dwarfs are ...

in the northern

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 ...

of Aries. With a normal

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction of the object's light ca ...

of 12.3, it is too faint to be seen by the

naked eye Naked eye, also called bare eye or unaided eye, is the practice of engaging in visual perception unaided by a magnification, magnifying, Optical telescope#Light-gathering power, light-collecting optical instrument, such as a telescope or microsc ...

, although it lies relatively close at a distance of . It is a

flare star A flare star is a variable star that can undergo unpredictable dramatic increases in brightness for a few minutes. It is believed that the flares on flare stars are analogous to solar flares in that they are due to magnetic reconnection, the magne ...

, which means it can suddenly increase in brightness for short periods of time.

Variability

William E. Kunkel announced that TZ Arietis is a

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

in 1968. It is a flare star, showing brief increases in brightness due to eruptions from its surface. In the

ultraviolet Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...

, flares of over a magnitude have been observed. In addition it shows longterm variations in brightness which may be due to starspots and rotation, possibly classifying it as a

BY Draconis variable BY Draconis variables are variable stars of late spectral types, usually K or M, and typically belong to the main sequence. The name comes from the archetype for this category of variable star system, BY Draconis. They exhibit variations in thei ...

. It was given the

variable star designation In astronomy, a variable-star designation is a unique identifier given to variable stars. It extends the Bayer designation format, with an identifying label (as described below) preceding the Latin genitive of the name of the constellation in whic ...

TZ Arietis in 1970.

Planetary system

In a

preprint In academic publishing, a preprint is a version of a scholarly or scientific paper that precedes formal peer review and publication in a peer-reviewed scholarly or scientific journal. The preprint may be available, often as a non-typeset versi ...

submitted to

arXiv arXiv (pronounced as "archive"—the X represents the Chi (letter), Greek letter chi ⟨χ⟩) is an open-access repository of electronic preprints and postprints (known as e-prints) approved for posting after moderation, but not Scholarly pee ...

in June 2019, three candidate planets were reported in orbit around this star (GJ 83.1) with orbital periods of 2, 240, and 770 days. A paper published in August 2020 reported a confirmation of the 240-day and 770-day planets, designating them "b" and "c", respectively. In March 2022, astronomers using the

Calar Alto Observatory The Calar Alto Observatory (Centro Astronómico Hispano en Andalucía or "Spanish Astronomical Centre in Andalusia") is an astronomical observatory located in Almería province in Spain on Calar Alto, a mountain in the Sierra de Los Filabre ...

in Spain, as part of the CARMENES survey project, reported an independent confirmation of the 770-day planet, which they designated "b". However, they found no evidence for the 240-day planet, and confidently defined the 2-day candidate as nothing more than a spurious chromatic effect of the star, linked to its rotation. The

NASA Exoplanet Archive The NASA Exoplanet Archive is an online astronomical exoplanet catalog and data service that collects and serves public data that support the search for and characterization of extra-solar planets (exoplanets) and their host stars. It is part of ...

still refers to the confirmed, 770-day planet as "c".

References

Notes

External links

luyten-1159-16

Image luyten-1159-16

GJ 83.1

Image TZ Arietis
{{Stars of Aries Local Bubble M-type main-sequence stars Aries (constellation) Flare stars 0083.1 Arietis, TZ J02001278+1303112 Planetary systems with one confirmed planet

Variability

Planetary system

References

Notes

Further reading

External links