In astronomy, a variable star designation is a unique identifier given to variable stars. It uses a variation on the Bayer designation format, with an identifying label preceding the Latin genitive of the name of the constellation in which the star lies. See List of constellations for a list of constellations and the genitive forms of their names. The identifying label can be one or two Latin letters or a V plus a number. Examples are R Coronae Borealis, YZ Ceti, V603 Aquilae.
62 Sagittarii (62 Sgr) or c Sagittarii (c Sgr) is an M-type giant star in the constellation of Sagittarius. It is the southwest corner of the asterism called the Terebellum. It is an irregular variable whose apparent visual magnitude varies between 4.45 and 4.64, and, at its brightest, it is the brightest of the four stars in the Terebellum. It is approximately 450 light-years from Earth. 62 Sagittarii is the star in the Terebellum which is most distant from its centre; it is 1.72° from its northwest corner, 60 Sagittarii, and 1.37° from its southeast corner, 59 Sagittarii.
Tau4 Serpentis, Latinized from τ4 Serpentis, is a M-type bright giant star in the constellation of Serpens, approximately 520 light-years from the Earth. It is classified as a semiregular late-type variable star, and its magnitude varies between +5.89 and +7.07 with a period of approximately 100 days. τ4 is unique among the stars with the Bayer designation τ Serpentis as being the only one with no HR catalog number.
An Alpha2 Canum Venaticorum variable is a type of variable star. These stars are chemically peculiar main sequence stars of spectral class B8p to A7p. They have strong magnetic fields and strong silicon, strontium, or chromium spectral lines. Their brightness typically varies by 0.01 to 0.1 magnitudes over the course of 0.5 to 160 days.
Alpha Antliae is the brightest star in the constellation of Antlia but it has not been given a proper name. It is approximately 320 light-years from the Solar System. It is a K-type giant star with an apparent visual magnitude of 4.25. This star has 2.2 times the mass of the Sun and has expanded to 41 times the solar radius. Compared to the Sun, it has only 41% of the abundance of elements other than hydrogen and helium.
The star HD 171978 is a spectroscopic binary in the constellation of Serpens. It consists of two A-type main sequence stars orbiting each other with a period of approximately 14.7 days. The overall apparent visual magnitude of the system varies between 5.74 and 5.86.
V337 Carinae is a K-type bright giant star in the constellation of Carina. It is an irregular variable and has an apparent visual magnitude which varies between 3.36 and 3.44.
S Arae (S Ara) is an A-type star in the constellation of Ara. It has an apparent visual magnitude which varies between 9.92 and 11.24.
R Aurigae (R Aur) is a M-type giant star in the constellation of Auriga. It has an apparent visual magnitude which varies between 6.7 and 13.9.
U Aquarii (U Aqr) is a star in the constellation of Aquarius. It has an apparent visual magnitude which varies between 10.6 and 15.9.
Alpha Microscopii (α Microscopii) is a star in the southern constellation of Microscopium. It is visible to the naked eye with an apparent visual magnitude that varies between 4.88 and 4.94. Based upon an annual parallax shift of 8.2214 mas as seen from the Earth, it is located 400 ± 30 light years from the Sun. The star is moving nearer to the Sun with a radial velocity of −15 km/s.
Alpha Octantis (Alpha Oct, α Octantis, α Oct) is a star in the constellation of Octans. Despite being labeled the "alpha" star by Johann Bayer in his star atlas Uranometria, it is not the brightest star in the constellation – that title belongs to Nu Octantis. It has an overall apparent visual magnitude of approximately 5.15 and is a spectroscopic binary star which consists of two giant stars, each with spectral type F, orbiting each other with a period of just over 9 days. The pair has also been classified as a Beta Lyrae-type eclipsing binary system. It is a bright X-ray source with a luminosity of 22.78×1029 ergs s−1.
Beta Chamaeleontis, Latinized from β Chamaeleontis, is a B-type main sequence star and is the third-brightest star in the constellation of Chamaeleon. It has an apparent visual magnitude that varies between 4.24 and 4.30.
Tau1 Serpentis, Latinized from τ1 Serpentis, is an M-type giant star in the constellation of Serpens, approximately 900 light-years from Earth. It has an apparent visual magnitude which varies between 5.13 and 5.20.
Beta Hydrae is a double star in the constellation of Hydra. Its overall apparent visual magnitude varies by 0.04 magnitudes with a period of 2.344 days, and is approximately 4.27 at maximum brightness. The brighter star in the double is a giant Bp star which has been classified as an α2 Canum Venaticorum variable.
FU Orionis is a variable star in the constellation of Orion, that in 1937 rose in apparent visual magnitude from 16.5 to 9.6, and has since been around magnitude 9. For a long time it was considered unique, but in 1970 a similar star, V1057 Cygni, was discovered, and a number of additional examples have been discovered since then. These stars constitute the FU Orionis class of variable stars, GCVS type FU, often nicknamed FUors. These stars are pre–main sequence stars which display an extreme change in magnitude and spectral type.
Zeta2 Scorpii is a K-type orange giant star in the constellation of Scorpius. It has an apparent visual magnitude which varies between 3.59 and 3.65, and is located near the blue-white supergiant star ζ1 Scorpii in Earth's sky. In astronomical terms, ζ2 is much closer to the Sun and unrelated to ζ1 except for line-of sight co-incidence. ζ1 is 5,700 light-years away and probably an outlying member of open star cluster NGC 6231, whereas ζ2 is a mere 132 lightyears distant and thus much less luminous in real terms. ζ2 can also be distinguished from its optical partner, ζ1, because of its orangish colour especially in long-exposure astrophographs.
Chi Ophiuchi is a Be star in the constellation of Ophiuchus. It has an apparent visual magnitude which varies between 4.18 and 5.0.
Chi2 Orionis is a B-type supergiant star in the constellation of Orion. It has an apparent visual magnitude of 4.63 but being quite distant, and heavily extinguished it burns with the greatest absolute visual light magnitude among stars in Orion within the near reaches of the galaxy, 0.9 of a magnitude greater than Rigel. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified.
R Capricorni (R Cap) is a star in the constellation of Capricornus. It has an apparent visual magnitude which varies between 9.4 and 14.9. A mira variable and ageing red giant, it is in the asymptotic giant branch stage of its lifespan.
