18 Aquilae

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Lithopsian (talk | contribs) at 15:08, 23 November 2022 (starbox detail). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

18 Aquilae
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]
Distanceapprox. 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
Mass5.6[6] M
Luminosity4,875[7] L
Rotational velocity (v sin i)50[2] km/s
Ab
Mass0.38[6] M
Luminosity12.7[7] L
B
Mass3.49[6] M
Other designations
Y Aquilae, 18 Aql, BD+10 3787, FK5 3525, HD 178125, HIP 93867, HR 7248, SAO 104488[8]
Database references
SIMBADdata

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[10]

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]

References

  1. ^ a b c d e 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. ^ a b c 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. ^ a b 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. ^ a b c d e 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.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  7. ^ a b 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. ^ a b 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.

External links