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LZ Cephei

A light curve for LZ Cephei, plotted from TESS data
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Cepheus
Right ascension	22 02 04.57263
Declination	+58° 00′ 01.3098″
Apparent magnitude (V)	5.6
Characteristics
Spectral type	O 9III (primary) + ON 9.7V (secondary)
Variable type	Rotating ellipsoidal variable
Astrometry
Proper motion (μ)	RA: −3.096±0.061 mas/yr Dec.: −2.611±0.054 mas/yr
Parallax (π)	0.9070 ± 0.0525 mas
Distance	3,600 ± 200 ly (1,100 ± 60 pc)
Orbit
Period (P)	3.070507 d
Eccentricity (e)	0.0
Inclination (i)	49±2.4°
Semi-amplitude (K1) (primary)	88.72±1.02 km/s
Semi-amplitude (K2) (secondary)	224.48±2.58 km/s
Details
Primary
Mass	16.0 M☉
Radius	11.7+3.3 −2.7 R☉
Luminosity	79,000 L☉
Surface gravity (log g)	3.71±0.02 cgs
Temperature	32,000±1,000 K
Secondary
Mass	6.5 M☉
Radius	9.4+2.6 −2.2 R☉
Luminosity	45,000 L☉
Surface gravity (log g)	3.48±0.02 cgs
Temperature	28,000±1,000 K
Other designations
14 Cephei, HD 209481, BD+57 2441, HIP 108772, HR 8406, SAO 33990
Database references
SIMBAD	data

LZ Cephei, also known by its Flamsteed designation 14 Cephei, is a star about 3,600 light years from the Earth, in the constellation Cepheus. Its apparent magnitude is 5.6, making it faintly visible to the naked eye of an observer far from city lights. The star is a rotating ellipsoidal variable whose brightness, as measured by the Hipparcos satellite, varies between magnitude 5.52 and 5.61.

LZ Cephei was discovered to be a binary star by William Edmund Harper in 1931. The orbital elements were first calculated by Robert Methven Petrie in 1962. It was discovered to be a variable star in 1972 by N. Kameswara Rao, using the Lick Observatory's 24 inch telescope. The star was given the variable star designation LZ Cephei in 1973. It was classified as an ellipsoidal variable by Hill et al. in 1976.

A 2011 study of LZ Cephei concluded that the existing data are best explained if the system is a semi-detached binary with either the primary or secondary star nearly filling its Roche lobe. The secondary star, now less massive than the primary, was originally the more massive star, and matter has been transferred from the secondary to the primary.

References

1. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 14 January 2023.
2. ^ Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
3. ^ Harries, T. J.; Hilditch, R. W.; Hill, G. (April 1998). "Interacting OB star binaries: LZ Cep, SZ Cam and IU AUR". Monthly Notices of the Royal Astronomical Society. 295 (2): 386–396. Bibcode:1998MNRAS.295..386H. doi:10.1046/j.1365-8711.1998.01340.x.
4. ^ Mahy, L.; Martins, F.; Machado, C.; Donati, J. F.; Bouret, J. C. (September 2011). "The two components of the evolved massive binary LZ Cephei. Testing the effects of binarity on stellar evolution". Astronomy & Astrophysics. 533. arXiv:1106.6162. Bibcode:2011A&A...533A...9M. doi:10.1051/0004-6361/201116993.
5. ^ Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869.
6. "14 Cep -- Spectroscopic Binary". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-01-14.
7. ^ Petrie, R. M. (May 1962). "The O-type spectroscopic binary 14 Cephei". Publications of the Dominion Astrophysical Observatory Victoria. 12: 111–116. Bibcode:1962PDAO...12..111P.
8. Kameswara Rao, N. (August 1972). "Light Variations of Three Spectroscopic Binaries". Publications of the Astronomical Society of the Pacific. 84 (500): 563–565. Bibcode:1972PASP...84..563K. doi:10.1086/129332.
9. Kukarkin, B. V.; Kholopov, P. N.; Kukarkina, N. P. (October 1973). "59th Name-List of Variable Stars". Information Bulletin on Variable Stars. 834 (1): 1. Bibcode:1973IBVS..834....1K.
10. Hill, G.; Hilditch, R. W.; Pfannenschmidt, E. L. (January 1976). "Photoelectric measures of variable stars observed at Mt. Kobau (1970 - 73)". Publications of the Dominion Astrophysical Observatory Victoria. 15: 1–35. Bibcode:1976PDAO...15....1H.

v t e Constellation of Cepheus
List of stars in Cepheus Cepheus in Chinese astronomy
Stars	Bayer α (Alderamin) β (Alfirk) γ (Errai) δ ε ζ η θ ι κ λ μ (Garnet Star) ν ξ (Kurhah) ο π ρ ρ Flamsteed 7 9 11 14 16 19 24 2 UMi Variable AR T V W RW VV VW WZ DH DO MY PV S SS ST U V354 V381 V419 HR 597 881 7955 8281 8442 8702 8748 8938 9038 HD 1 197911 204521 Other Gliese 809 WISE 0313+7807 WR 156 IRAS 23077+6707
Exoplanets γ Cephei Ab (Tadmor) TOI-1431 b
Star clusters	NGC 188 6939 7023 7129 7142 7160 7380 7419 7429 7510 Other Palomar 1
Nebulae	NGC NGC 40 NGC 7129 NGC 7139 NGC 7354 NGC 7538 NGC 7822 Other Seahorse Nebula Elephant's Trunk Nebula Ghost Nebula Gyulbudaghian's Nebula IC 1396 Iris Nebula L1157 S 155 SSTGFLS J222557+601148
Galaxies	NGC 2276 2300 6952 Other 3C 61.1 S5 0014+81 NVSS 2146+82 UGC 11861
Category

• Rotating ellipsoidal variables
• Cepheus (constellation)
• Hipparcos objects
• Henry Draper Catalogue objects
• Durchmusterung objects
• Objects with variable star designations
• Flamsteed objects
• Bright Star Catalogue objects