XZ Andromedae

Last updated
XZ Andromedae
XZAndLightCurve.png
The visual band light curve of XZ Andromedae is shown. The main plot shows the light curve over a full cycle, and the inset plot shows the primary minimum on an expanded scale. Adapted from Yang (2013) [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Andromeda
Right ascension 01h 56m 51.52427s [2]
Declination +42° 06′ 02.1813″ [2]
Apparent magnitude  (V)9.91 – 12.45 variable [3]
Characteristics
Spectral type A4IV-V + G5IV [4]
Apparent magnitude  (B)10.16 [5]
Apparent magnitude  (V)9.93 [5]
Apparent magnitude  (G)9.9856 [2]
Apparent magnitude  (J)9.373 [6]
Apparent magnitude  (H)9.210 [6]
Apparent magnitude  (K)9.188 [6]
B−V color index 0.2125 [5]
Variable type EA
Astrometry
Proper motion (μ)RA: 4.345±0.110 [2]   mas/yr
Dec.: −11.814±0.116 [2]   mas/yr
Parallax (π)1.8406 ± 0.0788  mas [2]
Distance 1,770 ± 80  ly
(540 ± 20  pc)
Orbit [4]
Period (P)1.357 days
Eccentricity (e)0
Inclination (i)89°
Periastron epoch (T)HJD 2449313.53084±0.00081
Details [4]
Primary
Mass 3.2  M☉
Radius 2.4  R☉
Temperature 9,500  K
Secondary
Mass 1.3  M☉
Radius 2.6  R☉
Temperature 5,500  K
Other designations
2MASS J01565151+4206021, BD+41 376, TYC 2824-1360-1
Database references
SIMBAD data

XZ Andromedae (also known as XZ And) 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. [3]

Contents

System

The primary star of the system has a mass of 3.2 M☉ and has a spectral type A4IV-V, meaning that it has intermediate characteristics between a main sequence star and a subgiant one. The secondary is less massive (1.3 M☉) but larger than the primary, so it's an evolved subgiant star and its spectral type is G5IV. [4] The secondary component will likely evolve into a white dwarf before the primary leaves the main sequence. [7] Since 2019, it is suspected that the eclipsing binary is orbited by an additional two similar stars in a 1:3 mean-motion resonance with periods 33.43 and 100.4 years. [8]

Variability

The variability of XZ Andromedae was discovered by Henrietta Levitt by examining photographs taken from 1916 to 1919. Variability was confirmed by Arville D. Walker and Priscilla Fairfield. The discovery was announced by Harlow Shapley in 1923. [9] The star, originally known as BD+41 376, received the variable star designation XZ Andromedae in 1924. [10]

Photometric periods of Algol variables matches the orbital period of the system. However, in XZ Andromedae have been observed slight period variations that can be reproduced with three different cycles of 137.5, 36.8 and 11.2 years, respectively. Each of them could be the effect of another faint body orbiting the binary system, but one of the two shorter cycles could also be an effect of magnetic interaction between stars (the Applegate mechanism). [4]

Other research [7] states that the long cycle is instead a long-term period increase caused by mass transfer from the secondary (that fills its Roche lobe) to the primary component.

Related Research Articles

<span class="mw-page-title-main">LN Andromedae</span> Star in the constellation Andromeda

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.

<span class="mw-page-title-main">LQ Andromedae</span> Star in the constellation Andromeda

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.

<span class="mw-page-title-main">WZ Andromedae</span> Eclipsing binary star in the constellation Andromeda

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.

<span class="mw-page-title-main">AB Andromedae</span> Binary star in the Andromeda constellation

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.

<span class="mw-page-title-main">AD Andromedae</span> Eclipsing binary star in the constellation Andromeda

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.

<span class="mw-page-title-main">BX Andromedae</span> Star in the constellation Andromeda

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.

<span class="mw-page-title-main">CC Andromedae</span> Star in the constellation Andromeda

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.

<span class="mw-page-title-main">CN Andromedae</span> Star in the constellation Andromeda

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.

<span class="mw-page-title-main">DS Andromedae</span> Eclipsing binary star in the constellation Andromeda

DS Andromedae 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.

<span class="mw-page-title-main">FF Andromedae</span> Star in the constellation Andromeda

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.

<span class="mw-page-title-main">GR Andromedae</span> Variable star in the constellation Andromeda

GR Andromedae is a variable star in the constellation Andromeda. Its apparent visual magnitude varies between 6.87 and 6.95 in a cycle of 518.2 days. It is classified as an α2 Canum Venaticorum variable.

<span class="mw-page-title-main">KZ Andromedae</span> Star in the constellation Andromeda

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.

<span class="mw-page-title-main">LP Andromedae</span> Star in the constellation Andromeda

LP Andromedae is a carbon star in the constellation Andromeda. It is also a Mira variable whose mean apparent visual magnitude is 15.12 and has pulsations with an amplitude of 1.50 magnitudes and a period of 614 days.

<span class="mw-page-title-main">QR Andromedae</span> Eclipsing binary star in the constellation Andromeda

QR Andromedae is an eclipsing binary star in the constellation Andromeda. Its maximum apparent visual magnitude is 12.16, but its light curve shows clearly eclipsing events where its brightness can drop to a magnitude of 13.07. This leads to its classification as an Algol variable star.

<span class="mw-page-title-main">QX Andromedae</span> Eclipsing binary star system in the constellation Andromeda

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.

<span class="mw-page-title-main">V455 Andromedae</span> Dwarf nova star in the constellation Andromeda

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.

<span class="mw-page-title-main">AI Phoenicis</span> Star in the constellation Phoenix

AI Phoenicis is a variable star in the constellation of Phoenix. An Algol-type eclipsing binary, its apparent magnitude is constant at 8.58 for most of the time, sharply dropping to 9.35 during primary eclipse and to 8.89 during secondary eclipse. The system's variability was discovered by W. Strohmeier in 1972. From parallax measurements by the Gaia spacecraft, the system is located at a distance of 560 light-years from Earth, in agreement with earlier estimates based on its luminosity.

<span class="mw-page-title-main">VV Ursae Majoris</span> Variable star system in the constellation Ursa Major

VV Ursae Majoris is a binary star system in the northern circumpolar constellation of Ursa Major, abbreviated VV UMa. It is a variable star system with a brightness that cycles around an apparent visual magnitude of 10.19, making it too faint to be visible to the naked eye. The system is located at a distance of approximately 1,500 light years based on parallax measurements.

<span class="mw-page-title-main">RS Sagittarii</span> Eclipsing binary star system in the constellation Sagittarius

RS Sagittarii is an eclipsing binary star system in the southern constellation of Sagittarius, abbreviated RS Sgr. It is a double-lined spectroscopic binary with an orbital period of 2.416 days, indicating that the components are too close to each other to be individually resolved. The system has a combined apparent visual magnitude of 6.01, which is bright enough to be faintly visible to the naked eye. During the primary eclipse the brightness drops to magnitude 6.97, while the secondary eclipse is of magnitude 6.28. The distance to this system is approximately 1,420 light years based on parallax measurements.

<span class="mw-page-title-main">V1149 Orionis</span> Binary star in the constellation Orion

HD 37824 is a spectroscopic binary star system in the constellation of Orion. It has the variable-star designation V1149 Orionis. With an apparent magnitude of 6.59, it is near the limit for naked eye observation from Earth, faintly visible as an orange-hued dot of light under dark skies. It is located approximately 492 light-years distant according to Gaia DR3 parallax measurements, and is moving further away at a heliocentric radial velocity of 26.90 km/s.

References

  1. ↑ Yang, Y. G. (December 2013). "A new photometry and period analysis of the Algol-type binary XZ And". New Astronomy. 25: 109–113. Bibcode:2013NewA...25..109Y. doi:10.1016/j.newast.2013.05.001 . Retrieved 13 October 2021.
  2. 1 2 3 4 5 6 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR.
  3. 1 2 XZ And, database entry, Combined General Catalog of Variable Stars (GCVS4.2, 2004 Ed.), N. N. Samus, O. V. Durlevich, et al., CDS ID II/250 Accessed on line 2018-10-17.
  4. 1 2 3 4 5 Demircan, O.; Akalin, A.; Selam, S.; Derman, E.; Mueyesseroglu, Z. (1995). "A period study of XZ Andromedae". Astronomy and Astrophysics Supplement. 114: 167. Bibcode:1995A&AS..114..167D.
  5. 1 2 3 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy & Astrophysics, 355: L27–L30, Bibcode:2000A&A...355L..27H.
  6. 1 2 3 Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
  7. 1 2 Yang, Y. -G. (2013). "A new photometry and period analysis of the Algol-type binary XZ And". New Astronomy. 25: 109–113. Bibcode:2013NewA...25..109Y. doi:10.1016/j.newast.2013.05.001.
  8. ↑ Yuan, Jin-Zhao; Qian, Sheng-Bang (2019), A strange phenomenon of XZ Andromedae: two Keplerian periods with a 1:3 ratio, arXiv: 1904.07373
  9. ↑ Shapley, Harlow (August 1923). "First list of Suspected objects". Harvard College Observatory Bulletin. 790: 1–3. Bibcode:1923BHarO.790R...1S . Retrieved 12 November 2024.
  10. ↑ Guthnick, P.; Prager, R.; Heise, E. (November 1924). "Benennung von neu entdeckten veränderlichen Sternen". Astronomische Nachrichten. 223 (3): 41. Bibcode:1924AN....223...41G . Retrieved 12 November 2024.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.