Alight curve for TZ Arietis, plotted fromTESS data.[11] The blue points show the BY Draconis-type variability, and the red points show a flare. The inset plot shows the flare with an expanded horizontal scale. The star's 2.0 day rotation period[12] is marked in green.
William E. Kunkel announced that TZ Arietis is avariable star in 1968.[13] It is a flare star, showing brief increases in brightness due to eruptions from its surface. In theultraviolet, 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 aBY Draconis variable.[14] It was given thevariable star designation TZ Arietis in 1970.[15]
In apreprint submitted toarXiv 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.[16] A paper published in August 2020 reported a confirmation of the 240-day and 770-day planets, designating them "b" and "c", respectively.[17]
In March 2022, astronomers using theCalar Alto Observatory in Spain, as part of theCARMENES 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.[18] TheNASA Exoplanet Archive still refers to the confirmed, 770-day planet as "c".[19]
^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.
^Kemmer, J.; Lafarga, M.; Fuhrmeister, B.; Shan, Y.; Schöfer, P.; Jeffers, S. V.; Caballero, J. A.; Quirrenbach, A.; Amado, P. J. (2025-04-11),The CARMENES search for exoplanets around M dwarfs. Cluster analysis of signals from spectral activity indicators to search for shared periods,arXiv:2504.08363
^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.
