The periodic variability of this star was discovered by
P. Guthnick and
R. Prager in 1929.[15][8] Its relative brightness has made this star the subject of regular observation since its discovery,[16] both photographically and then photoelectrically starting in 1957.[17] It was initially classed as a Bailey-type "a" RR Lyrae variable. The variations were found to be somewhat similar to
RR Lyrae, with the periodicity of TU UMa differing by less than 1% of a day.[16] However, no evidence of a long-period modulation, known as the
Blazhko effect, was found in this star.[17]
^Suntzeff, Nicholas B.; et al. (1994), "Summary of Delta S Metallicity Measurements for Bright RR Lyrae Variables Observed at Lick Observatory and KPNO between 1972 and 1987", The Astrophysical Journal Supplement Series, 93: 271,
Bibcode:
1994ApJS...93..271S,
doi:10.1086/192055.
^
abPena, J. H.; et al. (December 2008), "Physical parameters determination of the RR Lyrae stars RU Psc, SS Psc and TU UMa", Communications in Asteroseismology, 157: 357–358,
Bibcode:
2008CoAst.157..357P.
^
abSaha, A.; White, R. E. (February 1990), "A New Velocity Curve of the RR Lyrae Star TU Ursae Majoris: Evidence for Duplicity", Publications of the Astronomical Society of the Pacific, 102: 148,
Bibcode:
1990PASP..102..148S,
doi:
10.1086/132621,
S2CID119405334
^
abPreston, George W.; et al. (March 1961), "The Light and Radial-Velocity Variations of TU Ursae Majoris", Astrophysical Journal, 133: 484,
Bibcode:
1961ApJ...133..484P,
doi:
10.1086/147051.
^
abSzeidl, B.; et al. (January 1986), "Period Changes of RR Lyrae Stars II, TW Her, WZ Her, AV Peg and TU UMa", Communications of the Konkoly Observatory, X (89): 57–110,
Bibcode:
1986CoKon..89...57S.
^Kervella, P.; et al. (2019), "Binarity from Gaia DR2 and Hipparcos proper motion anomaly and common proper motion", Memorie della Societa Astronomica Italiana, 90: 340,
Bibcode:
2019MmSAI..90..340K.
^Wade, Richard A.; et al. (November 1999), "A Timing Model for the RR Lyrae Variable Star TU Ursae Majoris, a Probable Member of a Binary System", The Astronomical Journal, 118 (5): 2442–2450,
Bibcode:
1999AJ....118.2442W,
doi:
10.1086/301109,
S2CID122188784.
Further reading
Peña, J. H.; et al. (October 2012), "Strömgren uvby-beta photoelectric photometry of the variable stars RU Psc, SS Psc and TU UMa", Revista Mexicana de Astronomía y Astrofísica, 48: 299–303,
Bibcode:
2012RMxAA..48..299P.
Donley, J.; et al. (May 2002), "Light Maxima of the RRab Variable TU UMa in Early 2002", Information Bulletin on Variable Stars, 5273 (1): 1,
Bibcode:
2002IBVS.5273....1D.
Kiss, L. L.; et al. (June 1995), "A New Orbit of the Binary RR Lyrae Star TU UMa", Information Bulletin on Variable Stars, 4205 (1): 1,
Bibcode:
1995IBVS.4205....1K.