Location of TZ Arietis in the constellation Aries | |
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aries |
Right ascension | 02h 00m 12.95632s [1] |
Declination | +13° 03′ 07.0006″ [1] |
Apparent magnitude (V) | 12.298 [2] |
Characteristics | |
Spectral type | M4.5 V [3] |
U−B color index | +1.37 [4] |
B−V color index | +1.80 [4] |
R−I color index | 1.39 [3] |
Variable type | Flare star |
Astrometry | |
Radial velocity (Rv) | −28.29±0.25 [1] km/s |
Proper motion (μ) | RA: 1096.458 mas/yr [1] Dec.: -1771.526 mas/yr [1] |
Parallax (π) | 223.7321 ± 0.0699 mas [1] |
Distance | 14.578 ± 0.005 ly (4.470 ± 0.001 pc) |
Absolute magnitude (MV) | 14.03 [5] |
Details | |
Mass | 0.14 [6] M☉ |
Radius | 0.161 [7] R☉ |
Luminosity | 0.00135 [8] L☉ |
Surface gravity (log g) | 5.05 [6] cgs |
Temperature | 3,158 [7] K |
Metallicity [Fe/H] | −0.14 [7] dex |
Rotational velocity (v sin i) | 3.8 [8] km/s |
Age | 4.8 [6] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
TZ Arietis (also known as Gliese 83.1, GJ 9066, or L 1159-16) is a red dwarf in the northern constellation of Aries. With a normal apparent visual magnitude of 12.3, it is too faint to be seen by the naked eye, although it lies relatively close at a distance of 14.6 light-years (4.47 parsecs ). It is a flare star, which means it can suddenly increase in brightness for short periods of time.
William E. Kunkel announced that TZ Arietis is a variable star in 1968. [12] It is a flare star, showing brief increases in brightness due to eruptions from its surface. In the ultraviolet, 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. [13] It was given the variable star designation TZ Arietis in 1970. [14]
In a preprint submitted to arXiv 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. [15] A paper published in August 2020 reported a confirmation of the 240-day and 770-day planets, designating them "b" and "c", respectively. [16]
In March 2022, astronomers using the Calar Alto Observatory 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. [17] The NASA Exoplanet Archive still refers to the confirmed, 770-day planet as "c". [18]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b [note 1] | ≥0.21±0.02 MJ | 0.88±0.02 | 771.36+1.34 −1.23 | 0.46±0.04 | — | — |
Teegarden's Star is an M-type red dwarf star in the constellation Aries, 12.5 light-years from the Solar System. Although it is near Earth it is a dim magnitude 15 and can only be seen through large telescopes. This star was found to have a very large proper motion of about 5 arcseconds per year. Only seven stars with such large proper motions are currently known. Teegarden's Star hosts a planetary system with at least three planets.
Wolf 359 is a red dwarf star located in the constellation Leo, near the ecliptic. At a distance of 7.86 light-years from Earth, it has an apparent magnitude of 13.54 and can only be seen with a large telescope. Wolf 359 is one of the nearest stars to the Sun with only the Alpha Centauri system, Barnard's Star, and the brown dwarfs Luhman 16 and WISE 0855−0714 known to be closer. Its proximity to Earth has led to its mention in several works of fiction.
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DX Cancri is a variable star in the northern zodiac constellation of Cancer. With an apparent visual magnitude of 14.81, it is much too faint to be seen with the naked eye. Visually viewing this star requires a telescope with a minimum aperture of 16 in (41 cm). Based upon parallax measurements, DX Cancri is located at a distance of 11.8 light-years from Earth. This makes it the 18th closest star to the Sun. It is a proposed member of the Castor Moving Group of stars that share a common trajectory through space. This group has an estimated age of 200 million years.
YZ Ceti is a red dwarf star in the constellation Cetus. Although it is relatively close to the Sun at just 12 light years, this star cannot be seen with the naked eye. It is classified as a flare star that undergoes intermittent fluctuations in luminosity. YZ Ceti is about 13 percent the mass of the Sun and 17% of its radius.
Gliese 674(GJ 674) is a small red dwarf star with an exoplanetary companion in the southern constellation of Ara. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 9.38 and an absolute magnitude of 11.09. The system is located at a distance of 14.85 light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −2.9 km/s. It is a candidate member of the 200 million year old Castor stream of co-moving stars.
AD Leonis (Gliese 388) is a red dwarf star. It is located relatively near the Sun, at a distance of 16.2 light-years, in the constellation Leo. AD Leonis is a main sequence star with a spectral classification of M3.5V. It is a flare star that undergoes random increases in luminosity.
GJ 1245 is a double star with components G 208-44 and G 208-45, located 15.2 light-years away in the constellation Cygnus. G 208-44 is itself a closer double star made up of two red dwarfs, while G 208-45 is also a red dwarf. GJ 1245 is the 43rd closest stellar system to the Solar System. GJ 1245 A and B are active flare stars, and the pair are collectively designated V1581 Cygni.
Gliese 412 is a pair of stars that share a common proper motion through space and are thought to form a binary star system. The pair have an angular separation of 31.4″ at a position angle of 126.1°. They are located 15.8 light-years distant from the Sun in the constellation Ursa Major. Both components are relatively dim red dwarf stars.
Gliese 752 is a binary star system in the Aquila constellation. This system is relatively nearby, at a distance of 19.3 light-years.
YZ Canis Minoris is a red-hued star in the equatorial constellation of Canis Minor. With an apparent visual magnitude of 11.15, it is much too faint to be viewed with the naked eye. The distance to YZ CMi can be estimated from its annual parallax shift of 167 mas, yielding a value of 19.5 light years. Presently the star is moving further away with a heliocentric radial velocity of +26.5 km/s. It made its closest approach some 162,000 years ago when it made perihelion passage at a distance of 10.2 ly. YZ CMi is a potential member of the Beta Pictoris moving group.
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GJ 3323 is a nearby single star located in the equatorial constellation Eridanus, about 0.4° to the northwest of the naked eye star Psi Eridani. It is invisible to the naked eye with an apparent visual magnitude 12.20. Parallax measurements give a distance estimate of 17.5 light-years from the Sun. It is drifting further away with a radial velocity of +42.3 km/s. Roughly 104,000 years ago, the star is believed to have come to within 7.34 ± 0.16 light-years of the Solar System.
GJ 625 is a small red dwarf star with an exoplanetary companion in the northern constellation of Draco. The system is located at a distance of 21.1 light-years from the Sun based on parallax, but is drifting closer with a radial velocity of −13 km/s. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 10.13 and an absolute magnitude of 11.06.
GJ 3512 is a nearby star in the northern circumpolar constellation of Ursa Major. It is invisible to the naked eye but can be observed using a telescope, having an apparent visual magnitude of +15.05. The star is located at a distance of 31 light-years from the Sun based on parallax. It has a high proper motion, traversing the celestial sphere at the rate of 1.311″ yr−1. The measurement of the star's radial velocity is poorly constrained, but it appears to be drifting further away at a rate of ~8 km/s.
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