TZ Mensae

TZ Mensae

A light curve for TZ Mensae plotted from TESS data
Observation data
Epoch J2000.0      Equinox ICRS
Constellation Mensa
Right ascension 05h 30m 13.8827s
Declination −84° 47′ 06.366″
Apparent magnitude (V) 6.19 to 6.87
Characteristics
U−B color index −0.11
B−V color index −0.02
Variable type Algol variable
A
Spectral type A0 V
B
Spectral type A8 V
Astrometry
Radial velocity (Rv)−0.3±0.9 km/s
Proper motion (μ) RA: −6.242 mas/yr
Dec.: +43.141 mas/yr
Parallax (π)8.0907±0.0381 mas
Distance403 ± 2 ly
(123.6 ± 0.6 pc)
Absolute magnitude (MV)+0.93 (combined)
Orbit
PrimaryA
SecondaryB
Period (P)8.569 d
Semi-major axis (a)0.13 AU
Eccentricity (e)0.035±0.007
Inclination (i)88.73°
Periastron epoch (T)2442403.7085
Argument of periastron (ω)
(secondary)		295°
Semi-amplitude (K1)
(primary)		62.2 km/s
Semi-amplitude (K2)
(secondary)		102.8 km/s
Details
A
Mass2.49±0.02 M☉
Radius1.90±0.02 R☉
Luminosity39.8+7
−6 L☉
Surface gravity (log g)4.22±0.01 cgs
Temperature10,543+421
−405 K
Rotational velocity (v sin i)16±4 km/s
B
Mass1.50±0.01 M☉
Radius1.40±0.01 R☉
Luminosity4.57+0.8
−0.7 L☉
Surface gravity (log g)4.30±0.01 cgs
Temperature7178+303
−291 K
Rotational velocity (v sin i)12 km/s
Metallicity [Fe/H]−0.12±0.05 dex
Age141±3 Myr
Other designations
31 G. Mensae, TZ Men, CD−84°63, CPD−84°75, FK5 1659, GC 7134, HD 39780, HIP 25776, HR 2059, SAO 258418
Database references
SIMBADdata

TZ Mensae is a binary star in the southern circumpolar constellation Mensa. The system has a combined maximum apparent magnitude of 6.19, placing it near the limit for naked eye visibility. Parallax measurements place the system at a distance of 403 light years. The radial velocity is small.

The components of TZ Mensae have stellar classifications of A0 V and A8 V, both indicating that they are ordinary A-type main-sequence stars. They have masses of 1.5 and 2.5 M☉, and radii of 1.4 and 1.9 R☉, respectively. The primary has an effective temperature of 10,543 K and a luminosity 40 times that of the Sun (L☉). As for the companion, it has a temperature of 7,178 K. and a luminosity less than five L☉ The rotation of both stars is apparently synchronous with the orbital period, with projected rotational velocities of 12 and 16 km/s respectively. The system is estimated to be 141 million years old.

The two components take about 8 days to revolve around each other in a relatively circular orbit. Since the inclination is close to 90° (actually 88.7°), the two stars periodically pass in front of one another and it has been classified as a eclipsing binary, specifically the Algol type. If the brighter component is eclipsing the dimmer one, the brightness drops to 6.36. If vice versa, it drops to 6.87, which is below the limit for naked eye visibility.

References

  1. ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
  2. 1 2 3 4 5 6 Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  3. 1 2 Watson, C. L.; Henden, A. A.; Price, A. (May 2006). "The International Variable Star Index (VSX)". Society for Astronomical Sciences Annual Symposium. 25: 47. Bibcode:2006SASS...25...47W.
  4. 1 2 Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99–110. Bibcode:1966CoLPL...4...99J.
  5. 1 2 3 Samus’, N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. ISSN 1063-7729. S2CID 255195566.
  6. 1 2 3 4 5 6 Kovaleva, D. A. (December 2001). "Age and metallicity estimates for moderate-mass stars in eclipsing binaries". Astronomy Reports. 45 (12): 972–983. Bibcode:2001ARep...45..972K. doi:10.1134/1.1426128. eISSN 1562-6881. ISSN 1063-7729. S2CID 121028634.
  7. 1 2 Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. ISSN 1063-7737. S2CID 119231169.
  8. ↑ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
  9. 1 2 3 4 5 6 7 8 Andersen, J.; Clausen, J. V.; Nordstrom, B. (March 1987). "Absolute dimensions of eclipsing binaries. XII. TZ Mensae". Astronomy and Astrophysics. 175: 60–70. Bibcode:1987A&A...175...60A. ISSN 0004-6361.
  10. 1 2 3 4 Malkov, O. Yu. (January 1993). "Catalogue of astrophysical parameters of binary systems". Bulletin d'Information du Centre de Donnees Stellaires. 42: 27. Bibcode:1993BICDS..42...27M. ISSN 1169-8837.
  11. ↑ Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
  12. ↑ "TZ Men". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved July 9, 2022.
  13. ↑ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.