TZ Arietis (also known as Gliese 83.1, GJ 9066, or L 1159-16) is a
red dwarf in the
northernconstellation 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 to the
Sun 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.
Variability
TZ Arietis is a
variable star. 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.[10] It was given the
variable star designation TZ Arietis in 1970.[11]
Planetary system
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.[12] A paper published in August 2020 reported a confirmation of the 240-day and 770-day planets, designating them "b" and "c", respectively.[13]
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.[14] The
NASA Exoplanet Archive still refers to the confirmed, 770-day planet as "c".[15]
^Landolt, Arlo U. (July 1992), "UBVRI photometric standard stars in the magnitude range 11.5-16.0 around the celestial equator", Astronomical Journal, 104 (1): 340–371, 436–491,
Bibcode:
1992AJ....104..340L,
doi:10.1086/116242.
^
abNicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49,
Bibcode:
1978A&AS...34....1N.
^
abcHoudebine, Éric R.; Mullan, D. J.; Doyle, J. G.; de la Vieuville, Geoffroy; Butler, C. J.; Paletou, F. (2019), "The Mass–Activity Relationships in M and K Dwarfs. I. Stellar Parameters of Our Sample of M and K Dwarfs", The Astronomical Journal, 158 (2): 56,
arXiv:1905.07921,
Bibcode:
2019AJ....158...56H,
doi:10.3847/1538-3881/ab23fe,
S2CID159041104.
^Gershberg, R. E.; Katsova, M. M.; Lovkaya, M. N.; Terebizh, A. V.; Shakhovskaya, N. I. (1999), "Catalogue and bibliography of the UV Cet-type flare stars and related objects in the solar vicinity", Astronomy and Astrophysics Supplement Series, 139 (3): 555–558,
Bibcode:
1999A&AS..139..555G,
doi:10.1051/aas:1999407.
^Kukarkin, B. V.; Kholopov, P. N.; Perova, N. B. (October 1970), "57th Name-List of Variable Stars", Information Bulletin on Variable Stars, 480 (1): 1,
Bibcode:
1970IBVS..480....1K.
^Barnes, J. R.; et al. (2019-06-11), Frequency of planets orbiting M dwarfs in the Solar neighbourhood,
arXiv:1906.04644.
^Feng, Fabo; Shectman, Stephen A.; Clement, Matthew S.; Vogt, Steven S.; Tuomi, Mikko; Teske, Johanna K.; Burt, Jennifer; Crane, Jeffrey D.; Holden, Bradford; Wang, Sharon Xuesong; Thompson, Ian B.; Díaz, Matías R.; Butler, R. Paul (2020), "Search for Nearby Earth Analogs .III. Detection of 10 New Planets, 3 Planet Candidates, and Confirmation of 3 Planets around 11 Nearby M Dwarfs", The Astrophysical Journal Supplement Series, 250 (2): 29,
arXiv:2008.07998,
Bibcode:
2020ApJS..250...29F,
doi:10.3847/1538-4365/abb139,
S2CID221150644.
Harrington, R. S.; Dahn, C. C. (April 1980), "Summary of U.S. Naval Observatory parallaxes", Astronomical Journal, 85: 454–465,
Bibcode:
1980AJ.....85..454H,
doi:
10.1086/112696.