18 Aquilae

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18 Aquilae
Aquila constellation map.svg
Red circle.svg
Location of 18 Aquilae (circled)
Observation data
Epoch J2000       Equinox J2000
Constellation Aquila
Right ascension 19h 06m 58.60289s [1]
Declination +11° 04′ 16.4173″ [1]
Apparent magnitude  (V)5.072
Characteristics
Spectral type B8 III [2]
U−B color index −0.44 [3]
B−V color index −0.08 [3]
Variable type Eclipsing [4]
Astrometry
Radial velocity (Rv)−18.6 [5]  km/s
Proper motion (μ)RA: −0.89 [1]   mas/yr
Dec.: −32.11 [1]   mas/yr
Parallax (π)6.43 ± 0.79  mas [1]
Distance approx. 510  ly
(approx. 160  pc)
Orbit [6]
PrimaryA
CompanionB
Period (P)205.16 yr
Semi-major axis (a)0.399″
Eccentricity (e)0.23
Inclination (i)134.3°
Orbit [6]
PrimaryAa
CompanionAb
Period (P)1.3023  d
Semi-amplitude (K1)
(primary)		27.6 km/s
Details
Aa
Mass 5.6 [6]   M☉
Luminosity 4,875 [7]   L☉
Rotational velocity (v sin i)50 [2]  km/s
Ab
Mass 0.38 [6]   M☉
Luminosity12.7 [7]   L☉
B
Mass 3.49 [6]   M☉
Other designations
Y Aquilae, 18 Aql, BD+10 3787, FK5 3525, HD  178125, HIP 93867, HR 7248, SAO  104488 [8]
Database references
SIMBAD data

18 Aquilae (abbreviated 18 Aql) is a triple star [9] system in the constellation of Aquila. 18 Aquilae is the Flamsteed designation; it also bears the variable star designation Y Aquilae. It has an apparent visual magnitude of 5.07. The distance to this system can be estimated from the annual parallax shift of 6.43  mas, yielding a value of around 510 light-years (160 parsecs ) away from Earth.

A light curve for Y Aquilae, plotted from TESS data YAqlLightCurve.png
A light curve for Y Aquilae, plotted from TESS data

The inner pair of stars in this system form a spectroscopic binary with a combined magnitude of 5.44 and an orbital period of 1.302 days. The primary component is a giant star with a stellar classification of B8 III. [2] Because the orbital plane is inclined near the line of sight, two form an eclipsing binary system. The eclipse of the primary component causes a 0.04 drop in magnitude, while the eclipse of the secondary results in a decrease of 0.03. [11] At an angular separation of 0.310  arcseconds is the magnitude 6.39 tertiary component. [9] This system has a high peculiar velocity of 29.7 ± 3.9 km/s relative to the neighboring stars. [12]

Related Research Articles

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Theta Ursae Minoris, Latinized from θ Ursae Minoris, is a suspected binary star system that is visible to the naked eye in the northern circumpolar constellation of Ursa Minor. It is roughly 860 light years from Earth with an apparent visual magnitude of 5.0. The system is moving closer to the Sun with a radial velocity of −25 km/s.

21 Aquilae is a solitary variable star in the equatorial constellation of Aquila. It has the variable star designation V1288 Aql; 21 Aquilae is its Flamsteed designation. This object is visible to the naked eye as a dim, blue-white hued star with a baseline apparent visual magnitude of 5.14. The star is located at a distance of around 740 light-years from Earth, give or take a 30 light-year margin of error. It is moving closer to the Earth with a heliocentric radial velocity of –5 km/s.

5 Aquilae is a quadruple star system in the constellation of Aquila. 5 Aquilae is the Flamsteed designation. The combined apparent visual magnitude of the system is 5.9, which means it is faintly visible to the naked eye. With an annual parallax shift of 8.94 mas, the distance to this system is estimated as approximately 360 light-years, albeit with a 13% margin of error.

<span class="mw-page-title-main">10 Aquilae</span> Chemically peculiar F-type star in the constellation Aquila

10 Aquilae is a star in the equatorial constellation of Aquila. 10 Aquilae is the Flamsteed designation. It has an apparent visual magnitude of 5.9 and thus is a faint star that is just visible to the naked eye in dark skies. The brightness of this star is diminished by 0.17 in visual magnitude from extinction caused by interstellar gas and dust. Based on an annual parallax shift of 13.45 mas, the distance to this star is around 240 light-years.

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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.

47 Boötis is a binary star system in the northern constellation of Boötes, located 261 light years away from the Sun. It has the Bayer designation k Boötis; 47 Boötis is the Flamsteed designation. The system is visible to the naked eye as a faint, white-hued star with a combined apparent visual magnitude of 5.58. It is moving closer to the Earth with a heliocentric radial velocity of −13 km/s.

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<span class="mw-page-title-main">V357 Carinae</span> Binary star in the constellation Carina.

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<span class="mw-page-title-main">V Aquilae</span> Carbon star in the constellation Aquila

V Aquilae is a carbon star and semiregular variable star in the constellation Aquila. It has an apparent magnitude which varies between 6.6 and 8.4 and is located around 400 parsecs (1,300 ly) away.

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

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<span class="mw-page-title-main">YZ Cassiopeiae</span> Triple star system in the constellation Cassiopeia

YZ Cassiopeiae is a star system 103.8 parsecs (339 ly) away from Earth, in the constellation Cassiopeia. It comprises three stars: an eclipsing Algol-type binary and a visually fainter star about 3000 AU distant.

Lambda Cygni is a class B5V star in the constellation Cygnus. Its apparent magnitude is 4.54 and it is approximately 770 light years away based on parallax.

47 Cygni is a triple star system in the northern constellation of Cygnus, and is located around 4,000 light years from the Earth. It is visible to the naked eye with a combined apparent visual magnitude of 4.61. The system is moving closer to the Earth with a heliocentric radial velocity of −4.6 km/s.

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<span class="mw-page-title-main">Lambda Pavonis</span> Star in the constellation Pavo

λ Pavonis, Latinized as Lambda Pavonis, is a single, variable star in the southern constellation of Pavo. It is a blue-white hued star that is faintly visible to the naked eye with an apparent visual magnitude that fluctuates around 4.22. This object is located approximately 1,400 light years from the Sun, based upon parallax. It is a member of the Scorpius–Centaurus association.

<span class="mw-page-title-main">42 Persei</span> Binary star system in the constellation Perseus

42 Persei is a binary star system in the northern constellation of Perseus. It has the Bayer designation n Persei, while 42 Persei is the Flamsteed designation. The system is visible to the naked eye as a dim, white-hued point of light with an apparent visual magnitude of 5.11. It is located around 93 parsecs (302 ly) distant from the Sun, but is drifting closer with a radial velocity of −12.4 km/s.

<span class="mw-page-title-main">W Aquilae</span> Variable star in the constellation Aquila

W Aquilae is a variable star in the constellation of Aquila. It is a type of evolved star known as an S-type star. Due to its relatively close distance of 1,200 light-years and equatorial location, it is easy to observe and heavily studied.

Psi<sup>2</sup> Orionis Spectroscopic binary system in the constellation of Orion

Psi2 Orionis a binary star system in the equatorial constellation of Orion. It has an apparent visual magnitude of 4.6, indicating that it is visible to the naked eye. Based upon an annual parallax shift of 2.87 mass, it is roughly 1,100 light years distant from the Sun.

References

  1. 1 2 3 4 5 van Leeuwen, F. (November 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.
  2. 1 2 3 Levato, H. (January 1975). "Rotational velocities and spectral types for a sample of binary systems". Astronomy and Astrophysics Supplement Series. 19: 91–99. Bibcode:1975A&AS...19...91L.
  3. 1 2 Osawa, K.; Hata, S. (1962). "Three-color photometry of B8-A2 stars (II)". Annals of the Tokyo Astronomical Observatory. 7: 209. Bibcode:1962AnTok...7..209O.
  4. ↑ 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.
  5. ↑ Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Carnegie Institute Washington D.C. Publication. Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W.
  6. 1 2 3 4 5 Tokovinin, Andrei (2018-03-01). "The Updated Multiple Star Catalog". The Astrophysical Journal Supplement Series . 235 (1): 6. arXiv: 1712.04750 . Bibcode:2018ApJS..235....6T. doi:10.3847/1538-4365/aaa1a5. ISSN   0067-0049. S2CID   119047709.
  7. 1 2 De Greve, J. P.; Vanbeveren, D. (1980). "Close Binary Systems Before and after Mass Transfer - a Comparison of Observations and Theory". Astrophysics and Space Science. 68 (2): 433. Bibcode:1980Ap&SS..68..433D. doi:10.1007/BF00639709. S2CID   123281741.
  8. ↑ "18 Aql". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2012-07-25.
  9. 1 2 Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society . 389 (2): 869–879. arXiv: 0806.2878 . Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID   14878976.
  10. ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
  11. ↑ Malkov, O. Yu.; et al. (February 2006). "A catalogue of eclipsing variables". Astronomy and Astrophysics. 446 (2): 785–789. Bibcode:2006A&A...446..785M. doi: 10.1051/0004-6361:20053137 .
  12. ↑ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv: 1007.4883 . Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. S2CID   118629873.
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