Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Andromeda |
Right ascension | 23h 34m 37.53652s [2] |
Declination | +40° 14′ 11.1795″ [2] |
Apparent magnitude (V) | 5.55 [3] |
Characteristics | |
Spectral type | A1 III, [4] A1 Va, [5] or kA1hA3mA0.5 Va+. [6] |
U−B color index | 0.08 |
B−V color index | 0.096±0.005 [3] |
Variable type | δ Sct [7] |
Astrometry | |
Radial velocity (Rv) | 13.1±0.6 [3] km/s |
Proper motion (μ) | RA: -18.165 mas/yr Dec.: −46.183 [2] mas/yr |
Parallax (π) | 12.9406 ± 0.0973 mas [2] |
Distance | 252 ± 2 ly (77.3 ± 0.6 pc) |
Absolute magnitude (MV) | +1.16±0.16 [8] |
Details [4] | |
Mass | 2.7 M☉ |
Luminosity | 27 L☉ |
Surface gravity (log g) | 3.90±0.03 [8] cgs |
Temperature | 9,225 K |
Rotational velocity (v sin i) | 105 [8] km/s |
Age | 130 Myr |
Other designations | |
Database references | |
SIMBAD | data |
15 Andromedae, abbreviated 15 And, is a single, [10] variable star [7] in the northern constellation of Andromeda. 15 Andromedae is the Flamsteed designation, while its variable star designation is V340 And. [9] Its apparent visual magnitude is 5.55, [3] which indicates it is faintly visible to the naked eye. Its estimated distance from the Earth is 252 light years, and it is moving further away with a heliocentric radial velocity of 13 km/s. [3]
Rufener and Bartholdi (1982) included the star (under the name HD 221756) in their list of 333 variable, microvariable and suspected variable stars, based on multicolor photometry performed at several observatories in the 1960s and 1970s. However they were unable to conclusively demonstrate that the star's brightness varied. [11] Proof of variability, along with a light curve and period estimate of 63 minutes, was published by Paunzen and Handler in 1996. [12] The star was given its variable star designation, V340 Andromedae, in 1997. [13]
Depending on the source, this star has been classified as a giant star with a stellar classification of A1 III, [4] an A-type main-sequence star with a class of A1 Va, [5] or a Lambda Boötis star with a class of kA1hA3mA0.5 Va+. [6] It is a Delta Scuti variable that changes in brightness by 0.03 magnitude. [7] Two variability cycles, with periods 0.0403 and 0.0449 days, have been observed, a common feature for Lambda Boötis stars. [14] The star is around 130 [4] million years old and has a high rotation rate, showing a projected rotational velocity of 105 km/s. [8] It has 2.7 times the mass of the Sun and is radiating 27 times the Sun's luminosity from its photosphere at an effective temperature of 9,225 K. [4]
This system has an excess emission of infrared radiation that suggests the presence of an orbiting disk of dust at a distance of around 50 AU from the host star. [4]
Rho Serpentis, Latinized from ρ Serpentis, is a single star in the Caput section of the equatorial Serpens constellation. It has an orange hue and is faintly visible to the naked eye with an apparent visual magnitude of +4.78. The distance to this star is approximately 375 light years based on parallax, but it is drifting closer to the Sun with a radial velocity of −62 km/s.
Sigma Serpentis, Latinized from σ Serpentis, is a star in the equatorial constellation Serpens. It is faintly visible to the naked eye with an apparent visual magnitude of +4.82. Based upon an annual parallax shift of 36.67 mas as seen from Earth, it is located 89 light years from the Sun. The star is moving closer to the Sun with a radial velocity of −49 km/s.
Iota Andromedae is a single star in the northern constellation of Andromeda. It has the Flamsteed designation 17 Andromedae, while Iota Andromedae is the Bayer designation as Latinized from ι Andromedae. This object is visible to the naked eye at night as a faint, blue-white hued star with an apparent visual magnitude of +4.29. Based upon parallax measurements, it is located approximately 500 light years distant from the Sun.
Delta2 Tauri is a solitary, white-hued star in the zodiac constellation of Taurus. Based upon an annual parallax shift of 20.21 mas as seen from Earth, it is located roughly 161 light years distant from the Sun. It is separated from δ1 Tauri by 0.3° on the sky and is faintly visible to the naked eye with an apparent visual magnitude of +4.80. The star is considered a member of the Hyades cluster.
2 Andromedae, abbreviated 2 And, is a binary star system in the northern constellation of Andromeda. 2 Andromedae is the Flamsteed designation. It is a faint star system but visible to the naked eye with a combined apparent visual magnitude of 5.09. Based upon an annual parallax shift of 7.7 mas, it is located 420 light years away. The binary nature of the star was discovered by American astronomer Sherburne Wesley Burnham at Lick Observatory in 1889. The pair orbit each other over a period of 74 years with a high eccentricity of 0.8.
9 Andromedae, abbreviated 9 And by convention, is a variable binary star system in the northern constellation Andromeda. 9 Andromedae is the Flamsteed designation, while it bears the variable star designation AN Andromedae, or AN And. The maximum apparent visual magnitude of the system is 5.98, which places it near the lower limit of visibility to the human eye. Based upon an annual parallax shift of 7.1 mas, it is located 460 light years from the Earth.
26 Arietis is a variable star in the northern constellation of Aries. 26 Arietis is the Flamsteed designation; it also bears the variable star designation UU Arietis. The apparent visual magnitude of this star is 6.14, which, according to the Bortle Dark-Sky Scale, is within the naked eye visibility limit in dark rural skies. The annual parallax shift of 13.78 mas is equivalent to a distance of approximately 215 light-years from Earth. The star is receding from the Earth with a heliocentric radial velocity of +15 km/s.
Theta Boötis, Latinized from θ Boötis, is a star in the northern constellation of Boötes the herdsman, forming a corner of the upraised left hand of this asterism. It has the traditional name Asellus Primus and the Flamsteed designation 23 Boötis. Faintly visible to the naked eye, this star has a yellow-white hue with an apparent visual magnitude of 4.05. It is located at a distance of 47.2 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −10.6 km/s.
Alpha Cygni variables are variable stars which exhibit non-radial pulsations, meaning that some portions of the stellar surface are contracting at the same time other parts expand. They are supergiant stars of spectral types B or A. Variations in brightness on the order of 0.1 magnitudes are associated with the pulsations, which often seem irregular, due to beating of multiple pulsation periods. The pulsations typically have periods of several days to several weeks.
Tau Cassiopeiae is a solitary, orange hued star in the northern constellation of Cassiopeia. It is bright enough to be seen with the naked eye, having an apparent visual magnitude of +4.86. Based upon an annual parallax shift of 18.75 mas as seen from Earth, this system is located about 174 light years from the Sun.
RV Caeli, also known as HD 28552, is a solitary, red hued variable star located in the southern constellation Caelum, the chisel. It has an apparent magnitude of 6.4, placing it near the limit for naked eye visibility. The object is located relatively far at a distance of 1,340 light years based on parallax measurements from Gaia DR3, but is rapidly receding with a heliocentric radial velocity of 98 km/s.
V385 Andromedae is a variable star in the constellation Andromeda, about 360 parsecs (1,200 ly) away. It is a red giant over a hundred times larger than the sun. It has an apparent magnitude around 6.4, just about visible to the naked eye in ideal conditions.
BX Boötis is a star in the northern constellation of Boötes. It is a dim star near the lower limit of visibility to the naked eye, having a nominal apparent visual magnitude of 6.35. Based upon an annual parallax shift of 10.81 mas, it is located 302 light years away. At that distance, the visual magnitude of the star is diminished by an extinction of 0.13 due to interstellar dust. It is moving closer with a heliocentric radial velocity of −11 km/s.
Chi2 Orionis is a B-type blue 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 brighter than Rigel. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. It is considered to be a member of the Gemini OB1 association.
HD 211575 is a star in the constellation Aquarius in between "Gamma Aquarii", "Pi Aquarii" and "Sadalmelik". It is a member of the corona of the Ursa Major moving group.
V529 Andromedae, also known as HD 8801, is a variable star in the constellation of Andromeda. It has a 13th magnitude visual companion star 15" away, which is just a distant star on the same line of sight.
BD Phoenicis is a variable star in the constellation of Phoenix. From parallax measurements by the Gaia spacecraft, it is located at a distance of 256 light-years from Earth. Its absolute magnitude is calculated at 1.5.
AZ Phoenicis is a variable star in the constellation of Phoenix. It has an average visual apparent magnitude of 6.47, so it is at the limit of naked eye visibility. From parallax measurements by the Gaia spacecraft, it is located at a distance of 322 light-years from Earth. Its absolute magnitude is calculated at 1.65.
HD 66920, also known as HR 3171, is a solitary, white hued star located in the southern circumpolar constellation Volans, the flying fish. It has an apparent magnitude of 6.33, placing it near the limit for naked eye visibility. Based on parallax measurements from the Gaia spacecraft, the star is estimated to be 428 light years distant. It appears to be receding from the Solar System, having a heliocentric radial velocity of 23.8 km/s. Pauzen et al. (2001) listed it as a λ Boötis star, but is now considered a non member.
HD 218108, also known as HR 8786, is a solitary, white hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 6.11, making it faintly visible to the naked eye under ideal conditions. Based on parallax measurements from Gaia DR3, the object is estimated to be 247 light years away. It appears to be approaching the Solar System with a fairly constrained radial velocity of −7 km/s. Paunzen et al. (2001) lists it as a λ Boötis star with a weak magnesium line.