Alpha Lacertae
star in the constellation Lacerta
Alpha Lacertae, also named Stellio, is a single white-hued star in the constellation of Lacerta, located 103 light-years from the Sun. It is the brightest star in Lacerta with an apparent visual magnitude of 3.76. The star is moving closer to the Earth with a heliocentric radial velocity of −4.5 km/s.
This is an ordinary A-type main-sequence star with a stellar classification of A1 V, which indicates it is generating energy through hydrogen fusion at its core. It is around 400 million years old with a relatively high rate of spin, showing a projected rotational velocity of 128 km/s. The star has 2.2 times the mass of the Sun and 2.1 times the Sun's radius. It is radiating 28 times the Sun's luminosity from its photosphere at an effective temperature of 9,050 K.
Alpha Lacertae has a visual companion, CCDM J22313+5017B, of spectral type A and apparent visual magnitude 11.8, approximately 36 arcseconds away. The companion is optical, a chance line-of-sight coincidence.
Naming
Alpha Lacertae, Latinised from α Lacertae, is the Bayer designation for this star; it has the Flamsteed designation 7 Lacertae.
In Chinese astronomy, 螣蛇 (Téng Shé), meaning Flying Serpent, refers to an asterism consisting of α Lacertae, 4 Lacertae, π2 Cygni, π1 Cygni, HD 206267, ε Cephei, β Lacertae, σ Cassiopeiae, ρ Cassiopeiae, τ Cassiopeiae, AR Cassiopeiae, 9 Lacertae, 3 Andromedae, 7 Andromedae, 8 Andromedae, λ Andromedae, κ Andromedae, ι Andromedae, and ψ Andromedae.
The public source identifies “Alpha Lacertae” as star in the constellation Lacerta. This brief keeps that definition visible, then builds a research path around Alpha, Lacertae and star.
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This entry incorporates text from “Alpha Lacertae” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.