LY Aurigae

Last updated
LY Aurigae
M 38.jpg
LY Aurigae is the bright star in the southeast corner of this picture of Messier 38
Observation data
Epoch J2000       Equinox J2000
Constellation Auriga
Right ascension 05h 29m 42.650s [1]
Declination +35° 22 30.09 [1]
Apparent magnitude  (V)6.85 [2] (6.66 - 7.35 [3] )
Characteristics
Spectral type O9II + O9III + B0.5III [4]
U−B color index −0.78 [5]
B−V color index +0.20 [5]
Variable type β Lyr [2]
Astrometry
Radial velocity (Rv)5.40 [6]  km/s
Proper motion (μ)RA: −0.20±3.19 [1]   mas/yr
Dec.: −1.17±2.07 [1]   mas/yr
Parallax (π)3.28 ± 2.40  mas [1]
Distance approx. 1,000  ly
(approx. 300  pc)
Absolute magnitude  (MV)−5.62 + −5.11 + −4.43 [4]
Orbit [4]
PrimaryAa
CompanionAb
Period (P)4.0025 days
Semi-major axis (a)36.1  R
Eccentricity (e)0.0
Inclination (i)87.7°
Semi-amplitude (K1)
(primary)
161.9 km/s
Semi-amplitude (K2)
(secondary)
294.3 km/s
Orbit [4]
PrimaryBa
CompanionBb
Period (P)20.4642 days
Eccentricity (e)0.246
Semi-amplitude (K1)
(primary)
33.0 km/s
Details [4]
Aa
Mass 25.5  M
Radius 16.1  R
Luminosity 214,000  L
Surface gravity (log g)3.425  cgs
Temperature 31,000  K
Rotational velocity (v sin i)194 km/s
Ab
Mass 14.0  M
Radius 12.6  R
Luminosity 135,000  L
Surface gravity (log g)3.378  cgs
Temperature 31,150  K
Rotational velocity (v sin i)152 km/s
B
Luminosity 47,000  L
Surface gravity (log g)4.00  cgs
Temperature 26,000  K
Rotational velocity (v sin i)30 km/s
Age 5  Myr
Other designations
LY  Aurigae, BD+35°1137, HD  35921, SAO  58105, HIP  25733, WDS  J05297+3523, AAVSO  0523+35
Database references
SIMBAD data

LY Aurigae is a multiple star system in the constellation Auriga. It is an eclipsing binary variable star, dropping in brightness by 0.7 magnitudes every 4 days. The system is around a thousand light years away in the Auriga OB1 stellar association.

Contents

System

LY Aurigae is a close visual binary. The two stars are magnitude 6.85 [7] and magnitude 8.35 [8] 0.6 arc-seconds apart. Each star is also a spectroscopic binary.

A visual band light curve for LY Aurigae, adapted from Mayer et al. (2013) LYAurLightCurve.png
A visual band light curve for LY Aurigae, adapted from Mayer et al. (2013)

LY Aur A is a double-lined spectroscopic binary with an O9 bright giant and an O9 giant star in contact and eclipsing each other as they orbit every 4 days. It is classified as a Beta Lyr eclipsing variable system. The primary eclipse is 0.69 magnitudes deep and the secondary eclipse is 0.60 magnitudes. [10] Because of the contact nature of the system and the deformed shapes of the stars, the magnitude varies constantly throughout the orbital cycle. The orbital period is slowly changing due to mass exchange between the stars. Each star is over a hundred thousand times the luminosity of the sun. [4]

LY Aur B is a single-lined spectroscopic binary with an orbital period of 20.5 days. It is probably an early B main sequence star and the companion is undetectable. The two stars combined are 47,000 times the luminosity of the sun. [4]

Related Research Articles

<span class="mw-page-title-main">Beta Aurigae</span> Binary star system in the northern constellation of Auriga

Beta Aurigae, officially named Menkalinan, is a binary star system in the northern constellation of Auriga. The combined apparent visual magnitude of the system is 1.9, making it the second-brightest member of the constellation after Capella. Using the parallax measurements made during the Hipparcos mission, the distance to this star system can be estimated as 81.1 light-years, give or take a half-light-year margin of error.

<span class="mw-page-title-main">Epsilon Aurigae</span> Multiple star system in the constellation of Auriga

Epsilon Aurigae is a multiple star system in the northern constellation of Auriga, the charioteer. It is an unusual eclipsing binary system comprising an F0 supergiant and a companion which is generally accepted to be a huge dark disk orbiting an unknown object, possibly a binary system of two small B-type stars. The distance to the system is still a subject of debate, but data from the Gaia spacecraft puts its distance at around 1,350±300 light years from Earth.

<span class="mw-page-title-main">Upsilon Sagittarii</span> Binary star system in the constellation Sagittarius

Upsilon Sagittarii is a spectroscopic binary star system in the constellation Sagittarius. Upsilon Sagittarii is the prototypical hydrogen-deficient binary (HdB), and one of only four such systems known. The unusual spectrum of hydrogen-deficient binaries has made stellar classification of Upsilon Sagittarii difficult.

<span class="mw-page-title-main">Chi Aurigae</span> Binary star system in the constellation Auriga

Chi Aurigae, Latinized from χ Aurigae, is the Bayer designation for a binary star system in the northern constellation of Auriga. It is faintly visible to the naked eye with an apparent visual magnitude of 4.74. The annual parallax shift of this object is much smaller than the measurement error, making distance estimates by that means unreliable. The estimated distance to this star is approximately 3,000 light years. The brightness of the star is diminished by 1.26 in magnitude from extinction caused by intervening gas and dust.

<span class="mw-page-title-main">9 Aurigae</span> Multiple star system in the constellation Auriga

9 Aurigae is a star system in Auriga (constellation). It has an apparent magnitude of about 5, making it visible to the naked eye in many suburban skies. Parallax estimates made by the Hipparcos spacecraft put it at about 85.7 light-years from the solar system.

<span class="mw-page-title-main">14 Aurigae</span> Quadruple star system in the constellation Auriga

14 Aurigae is a quadruple star system located 269 light years away from the Sun in the zodiac constellation of Auriga. It has the variable star designation KW Aurigae, whereas 14 Aurigae is the Flamsteed designation. It is visible to the naked eye as a faint, white-hued star with a combined apparent visual magnitude of 5.01. The system is moving closer to the Sun with a heliocentric radial velocity of −9 km/s.

40 Aurigae is a binary star in the constellation Auriga. Its apparent magnitude is 5.345, meaning it can just barely be seen with the naked eye. Based on parallax estimates made by the Hipparcos spacecraft, the system is located some 340 light-years away.

<span class="mw-page-title-main">RT Aurigae</span> Star in the constellation Auriga

RT Aurigae is a yellow supergiant variable star in the constellation Auriga, about 1,500 light years from Earth.

<span class="mw-page-title-main">WW Aurigae</span> Binary star in the constellation Auriga

WW Aurigae is an eclipsing binary star system in the northern constellation of Auriga. It has a combined maximum apparent visual magnitude of 5.86, which is bright enough to be dimly visible to the naked eye. Based upon an annual parallax shift of 11.0 mas, it is located 297 light years from the Earth. The system is moving further away with a heliocentric radial velocity of −9 km/s, having come to within 212.5 ly some 3.12 million years ago.

<span class="mw-page-title-main">AE Aurigae</span> Star in the constellation Auriga

AE Aurigae is a runaway star in the constellation Auriga; it lights the Flaming Star Nebula.

<span class="mw-page-title-main">AR Aurigae</span> Binary star system in the constellation Auriga

AR Aurigae, also known by its Flamsteed designation 17 Aurigae, is a binary star in the constellation Auriga. Based on parallax measurements made by the Hipparcos spacecraft, it is approximately 461 light-years from Earth.

Psi<sup>6</sup> Aurigae Binary star in the constellation Auriga

Psi6 Aurigae, Latinized from ψ6 Aurigae, is a spectroscopic binary star in the northern constellation of Auriga. It is a dim, naked eye star with an apparent visual magnitude of +5.22. Based upon a measured annual parallax shift of 9.05 ± 0.38 mas, it is approximately 360 light-years distant from the Earth.

<span class="mw-page-title-main">Omicron Cassiopeiae</span> Star in the constellation Cassiopeia

Omicron Cassiopeiae is a triple star system in the constellation Cassiopeia. It is approximately 700 light-years from Earth, based on its parallax. It is visible to the naked eye with a slightly variable apparent magnitude of about 4.5.

<span class="mw-page-title-main">IQ Aurigae</span> Star in the constellation Auriga

IQ Aurigae is a single, variable star in the northern constellation of Auriga. It is visible to the naked eye as a dim, white-hued star with an apparent visual magnitude that fluctuates around 5.38. The star is located at a distance of about 460 light-years from the Sun based on parallax and is drifting further away with a radial velocity of +28.6 km/s.

<span class="mw-page-title-main">EO Aurigae</span> Eclipsing binary star of Algol type in the constellation Auriga

EO Aurigae is an eclipsing binary of Algol type in the northern constellation of Auriga. With a combined apparent magnitude of 7.71, it is too faint to be seen with the unaided eye.

<span class="mw-page-title-main">IU Aurigae</span> Triple star system in the constellation Auriga

IU Aurigae is a triple star system in the constellation Auriga, consisting of an eclipsing binary pair orbiting a third component with a period of 335 years. This system is too faint to be viewed with the naked eye, having a peak apparent visual magnitude of 8.19. The eclipsing pair form a Beta Lyrae-type semidetached binary of two Bp stars with a period of 1.81147435 days. During the primary eclipse, the visual magnitude of the system drops to 8.89, while for the secondary it decreases to 8.74. The third component is a massive object with 17–18 M, and may actually be a binary – which would make this a quadruple star system.

<span class="mw-page-title-main">22 Vulpeculae</span> Binary star system in the constellation Vulpecula

22 Vulpeculae is a binary star system in the northern constellation Vulpecula. Based on its parallax, it is located some 1,490 light-years away, and it has an apparent magnitude of about 5.2, making it visible to the naked eye. The system is moving closer to the Earth with a heliocentric radial velocity of −23 km/s.

<span class="mw-page-title-main">1 Persei</span> Star in the constellation Perseus

1 Persei is an eclipsing binary star in the constellation Perseus. Its uneclipsed apparent magnitude is 5.49. The binary star consists of two B2 type main-sequence stars in a 25.9 day eccentric orbit. The stars are surrounded by a faint cloud of gas visible in mid-infrared, although whether they are the origin of the gas or simply passing through it is unclear.

<span class="mw-page-title-main">QZ Carinae</span> Star system in the constellation Carina

QZ Carinae is a multiple star system in the constellation Carina. It is the brightest member of the loose open cluster Collinder 228 and one of the brightest stars in the Carina Nebula. The apparent magnitude is variable from +6.16 to +6.49 with a period of 6 days.

<span class="mw-page-title-main">Y Cygni</span> Binary star in the constellation Cygnus

Y Cygni is an eclipsing and double-lined spectroscopic binary star system in the constellation of Cygnus. It is located about 4,900 light-years from Earth. The system was one of the first binaries with a convincing detection of the apsidal precession.

References

  1. 1 2 3 4 5 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752 . Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID   18759600. Vizier catalog entry
  2. 1 2 Stickland, D. J.; et al. (1994). "Spectroscopic binary orbits from ultraviolet radial velocities. Paper 15: LY Aurigae (HD 35921)". The Observatory. 114: 107–113. Bibcode:1994Obs...114..107S.
  3. Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  4. 1 2 3 4 5 6 7 Mayer, Pavel; Drechsel, Horst; Harmanec, Petr; Yang, Stephenson; Šlechta, Miroslav (2013). "The O-type eclipsing contact binary LY Aurigae - member of a quadruple system". Astronomy & Astrophysics. 559: A22. Bibcode:2013A&A...559A..22M. doi: 10.1051/0004-6361/201322153 .
  5. 1 2 Mayer, P.; Papoušek, J. (1988). "New photometric data on LY Aurigae". Contributions of the Astronomical Institute of Brno. 26. Bibcode:1988CoBrn..26.....M.
  6. Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G.; Udry, S. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv: astro-ph/0406573 . Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID   119387088.
  7. Paunzen, E. (2015). "A new catalogue of Strömgren-Crawford uvbyβ photometry". Astronomy & Astrophysics. 580: A23. arXiv: 1506.04568 . Bibcode:2015A&A...580A..23P. doi:10.1051/0004-6361/201526413. S2CID   73623700.
  8. Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (2002). "The Tycho double star catalogue". Astronomy and Astrophysics. 384: 180–189. Bibcode:2002A&A...384..180F. doi: 10.1051/0004-6361:20011822 .
  9. Mayer, Pavel; Drechsel, Horst; Harmanec, Petr; Yang, Stephenson; Šlechta, Miroslav (November 2013). "The O-type eclipsing contact binary LY Aurigae – member of a quadruple system". Astronomy & Astrophysics. 559: A22. Bibcode:2013A&A...559A..22M. doi: 10.1051/0004-6361/201322153 .
  10. Malkov, O. Yu.; Oblak, E.; Snegireva, E. A.; Torra, J. (2006). "A catalogue of eclipsing variables". Astronomy and Astrophysics. 446 (2): 785. Bibcode:2006A&A...446..785M. doi: 10.1051/0004-6361:20053137 .

See also