Location of DS Andromedae in NGC 752 (circled) | |
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Andromeda |
Right ascension | 01h 57m 46.0561s [1] |
Declination | +38° 04′ 28.43112″ [1] |
Apparent magnitude (V) | 10.44 – 10.93 variable [2] |
Characteristics | |
Spectral type | F3IV-V + G0V [3] |
Apparent magnitude (B) | 10.89 [4] |
Apparent magnitude (V) | 10.52 [4] |
Apparent magnitude (G) | 10.4555 [1] |
Apparent magnitude (J) | 9.653 [5] |
Apparent magnitude (H) | 9.481 [5] |
Apparent magnitude (K) | 9.407 [5] |
Variable type | Algol [2] |
Astrometry | |
Radial velocity (Rv) | 2.5±2.0 [3] km/s |
Proper motion (μ) | RA: 10.172±0.082 [1] mas/yr Dec.: 11.78±0.08 [1] mas/yr |
Parallax (π) | 2.1968 ± 0.0404 mas [1] |
Distance | 1,480 ± 30 ly (455 ± 8 pc) |
Orbit | |
Period (P) | 1.0105188 days [2] |
Semi-major axis (a) | 5.77 R☉ [3] |
Eccentricity (e) | 0 [3] |
Inclination (i) | 84.3 [3] ° |
Periastron epoch (T) | HJD 2,436,142.405 [3] |
Semi-amplitude (K1) (primary) | 110 [6] km/s |
Semi-amplitude (K2) (secondary) | 180 [6] km/s |
Details [3] | |
Primary | |
Mass | 1.58±0.17 M☉ |
Radius | 2.10±0.08 R☉ |
Luminosity | 8.3 L☉ |
Temperature | 6,775 K |
Age | 2 Gyr |
Secondary | |
Mass | 0.94±0.10 M☉ |
Radius | 1.19±0.05 R☉ |
Luminosity | 1.6 L☉ |
Temperature | 5,997 K |
Age | 2 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
DS Andromedae (often abbreviated to DS And) is an eclipsing binary star in the constellation Andromeda and a member of the open cluster NGC 752. Its maximum apparent visual magnitude is 10.44, but drops down to 10.93 during the main eclipse and to 10.71 during the secondary one.
The primary star has a spectral classification F3IV-V, matching the evidence for a star that is evolving off the main sequence and is expanding its radius. The secondary is thought to be a main sequence star with spectral type G0. It is not visible in the spectrum of DS Andromedae, but the temperature and spectral type can be estimated from the difference in brightness of the two components, determined from the eclipses. The two components are modelled to have apparent magnitudes of 10.62 and 12.47 respectively. [3]
The age of DS Andromedae appears to be very close to the hook at the end of main sequence phase of evolution and has just reached the subgiant branch. Its age can be determined at 2.0±0.2 Gyr from the NGC 752 main sequence turnoff and this allows its physical properties to be accurately calculated. It appears to be not quite filling its roche lobe and no mass transfer has taken place between the two stars; they are evolving as isolated stars. [3]
A. Alksnis discovered the variability of DS Andromedae's brightness in 1957, [8] by measuring 60 photographic plates. [9] The light curve of the star shows a main eclipse when the secondary star passes in front of the primary, and a secondary eclipse when the opposite occurs. This cycle repeats with a periodicity slightly over one day. Since the system is almost exactly edge-on the secondary eclipse is total, and allows the determination of the spectral type of the secondary component. The primary eclipse is annular as the smaller secondary passes in front of the hotter brighter primary. [3]
It is classified as an Algol variable (detached) star in the General Catalogue of Variable Stars, [2] but is sometimes considered to be a β Lyrae variable (contact). [10]
NGC 752 is an open cluster in the constellation Andromeda. The cluster was discovered by Caroline Herschel in 1783 and cataloged by her brother William Herschel in 1786, although an object that may have been NGC 752 was described by Giovanni Batista Hodierna before 1654.
LN Andromedae, also known as HD 217811, HR 8768, is a formerly suspected variable star in the constellation Andromeda. Located approximately 458 parsecs (1,490 ly) away from Earth, it shines with an apparent visual magnitude 6.41, thus it can be seen by the naked eye under very favourable conditions. Its spectral classification is B2V, meaning that it's a hot main sequence star, emitting light approximately with a blackbody spectrum at an effective temperature of 18,090 K.
WR 22, also known as V429 Carinae or HR 4188, is an eclipsing binary star system in the constellation Carina. The system contains a Wolf-Rayet (WR) star that is one of the most massive and most luminous stars known, and is also a bright X-ray source due to colliding winds with a less massive O class companion. Its eclipsing nature and apparent magnitude make it very useful for constraining the properties of luminous hydrogen-rich WR stars.
WR 9 is a spectroscopic binary in the constellation Puppis consisting of a Wolf-Rayet star and a class O star. It is around 12,000 light years away.
LQ Andromedae is a variable star in the constellation Andromeda. Its maximum apparent visual magnitude is 6.5, placing it at the limit of the visibility to the naked eye. The brightness, however, drops down to 6.66 with a periodic cycle of roughly 7.44 hours.
WZ Andromedae is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 11.6, but drops down to 12.00 during the main eclipse which occurs roughly every 16.7 hours.
XZ Andromedae is a binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 9.91, but drops down to 12.45 every 1.357 days. Its variability matches the behaviour of Algol variable stars.
AB Andromedae is a binary star in the constellation Andromeda. Paul Guthnick and Richard Prager discovered that the star is an eclipsing binary in 1927. Its maximum apparent visual magnitude is 9.49 but shows a variation in brightness down to a magnitude of 10.46 in a periodic cycle of roughly 8 hours. The observed variability is typical of W Ursae Majoris variable stars, so the two stars in this system form a contact binary.
AD Andromedae is an eclipsing binary in the constellation Andromeda. Its maximum apparent visual magnitude is 11.2, but it shows a decrease of 0.62 magnitudes during the main eclipse and 0.58 during the secondary one. It is classified as a Beta Lyrae variable star with a period of almost one day.
BM Andromedae is a T Tauri star in the constellation Andromeda. Its apparent visual magnitude has irregular variations between a maximum of 11.63 and a minimum of 14.02.
BX Andromedae is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 8.87. Within a cycle of approximately 14.6 hours, the brightness drops down to a magnitude of 9.53 during the main eclipse, and to a magnitude of 9.12 during the secondary one. It is classified as a Beta Lyrae variable.
CC Andromedae is a variable star in the constellation Andromeda. It is a pulsating star of the Delta Scuti type, with an apparent visual magnitude that varies between 9.19 and 9.46 with a periodicity of 3 hours.
CN Andromedae is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 9.62 and drops down to a minimum of 10.2 during the main eclipse. It is classified as a Beta Lyrae variable with a period roughly of 0.4628 days.
FF Andromedae is a spectroscopic binary in the constellation Andromeda. It has a typical apparent visual magnitude of 10.4, but undergoes flare events that can increase its brightness by about a magnitude.
GP Andromedae is a Delta Scuti variable star in the constellation Andromeda. It is a pulsating star, with its brightness varying with an amplitude of 0.55 magnitudes around a mean magnitude of 10.7.
KX Andromedae is a spectroscopic binary star in the constellation Andromeda. Its apparent visual magnitude varies between 6.88 and 7.28.
KZ Andromedae is a double lined spectroscopic binary in the constellation Andromeda. Its apparent visual magnitude varies between 7.91 and 8.03 during a cycle slightly longer than 3 days.
QX Andromedae is an eclipsing binary in the constellation Andromeda. It varies from a maximum apparent visual magnitude of 11.28 to a minimum of 11.50. Since it is impossible to specify the onset time of the eclipses, it is classified as a W Ursae Majoris variable star. It is also observed as an X-ray source and is a member of the open cluster NGC 752.
V455 Andromedae is a dwarf nova in the constellation Andromeda. It has a typical apparent visual magnitude of 16.5, but reached a magnitude of 8.5 during the only observed outburst.
WR 133 is a visually moderately bright Wolf-Rayet star. It is a spectroscopic binary system containing a Wolf-Rayet primary and a class O supergiant secondary. It is in the constellation of Cygnus, lying in the sky at the centre of the triangle formed by β and γ Cygni, near η Cygni. It is the brightest member of the sparse open cluster NGC 6871.