20 Aquilae

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20 Aquilae
20AqlLightCurve.png
A light curve for 20 Aquilae, plotted from Hipparcos data [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Aquila
Right ascension 19h 12m 40.71201s [2]
Declination −07° 56′ 22.2650″ [2]
Apparent magnitude  (V)5.362 [3]
Characteristics
Spectral type B3 V, [4] B3 IV, [5] or B2/3 II [6]
B−V color index +0.088 [3]
Astrometry
Radial velocity (Rv)−23.0±0.7 [7]  km/s
Proper motion (μ)RA: +14.040 [2]   mas/yr
Dec.: –6.814 [2]   mas/yr
Parallax (π)3.5374 ± 0.1720  mas [2]
Distance 920 ± 40  ly
(280 ± 10  pc)
Absolute magnitude  (MV)−2.02 [8]
Details
Mass 8.6±0.2 [9]   M☉
Luminosity (bolometric)7,284 [3]   L☉
Temperature 18,700 [3]   K
Rotational velocity (v sin i)133±6 [4]  km/s
Age 27.9±4.1 [9]   Myr
Other designations
20 Aql, NSV  11808, BD−08° 4887, GC  26461, HD  179406, HIP  94385, HR  7279, SAO  143134 [10]
Database references
SIMBAD data

20 Aquilae, abbreviated 20 Aql, is an irregular variable [11] star in the equatorial constellation of Aquila. 20 Aquilae is its Flamsteed designation. It ranges in magnitude from a peak of 5.33 down to 5.36, which is bright enough for the star to be visible to the naked eye. [12] The estimated distance to this star is around 920  light years, based upon an annual parallax shift of 3.5  mas . [2] The star is moving closer to the Earth with a heliocentric radial velocity of −23 km/s. [7]

There has been some disagreement over the stellar classification of this star. Buscombe (1962) listed a class of B3 IV, [5] which suggests a B-type subgiant star that has exhausted the hydrogen at its core and is expanding off the main sequence. Lesh (1968) [13] and Braganca et al. (2012) [4] matched a B-type main sequence star with a class of B3 V. However, Houk and Swift (1999) found a class of B2/3 II, [6] indicating this is an evolved bright giant.

The star is about 28 [9]  million years old with a high rate of spin, showing a projected rotational velocity of 133 km/s. [4] It has 8.6 [9] times the mass of the Sun and is radiating 7,284 times the Sun's luminosity from its photosphere at an effective temperature of 18,700 K. [3]

Related Research Articles

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

Lambda Aquilae, Latinized from λ Aquilae, is a star in the constellation Aquila. It has the traditional name Al Thalimain, which it shares with ι Aquilae. The name is derived from the Arabic الظلیمينal-ẓalīmayn "the two ostriches". Lambda Aquilae is more precisely Al Thalimain Prior. It has an apparent visual magnitude of 3.43, which is bright enough to be seen with the naked eye. Parallax measurements place it at a distance of about 125 light-years from Earth.

<span class="mw-page-title-main">Kappa Aquilae</span> Star in the constellation Aquila

Kappa Aquilae, Latinized from κ Aquilae, is the Bayer designation for a star in the equatorial constellation of Aquila. It is a faint star at apparent visual magnitude +4.957, but bright enough to be seen with the naked eye in dark suburban skies. The annual parallax is only 1.94 mas, which equates to a distance of approximately 1,700 light-years from Earth.

<span class="mw-page-title-main">Upsilon Aquilae</span> Star in the constellation Aquila

Upsilon Aquilae, Latinized from υ Aquilae, is the Bayer designation for a star in the equatorial constellation of Aquila. With an apparent visual magnitude of +5.91 it is a faint star but visible to the naked eye from suburban skies. It has an annual parallax shift of 18.66 mas, indicating a distance of around 175 light-years. The star is drifting closer with a radial velocity of –30 km/s.

69 Aquilae, abbreviated 69 Aql, is a star in the equatorial constellation of Aquila. 69 Aquilae is its Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 4.91. Based upon an annual parallax shift of 16.2 mas, it is located 201 light years away. The star is moving closer to the Earth with a heliocentric radial velocity of −22.5 km/s.

70 Aquilae, abbreviated 70 Aql, is a single orange-hued star in the equatorial constellation of Aquila. 70 Aquilae is its Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 4.90. The distance to 70 Aquilae, as determined from its annual parallax shift of 3.5 mas, is around 940 light years. The star is moving closer to the Earth with a heliocentric radial velocity of −9 km/s.

4 Aquilae, abbreviated 4 Aql, is a single, white-hued star in the equatorial constellation of Aquila. 4 Aquilae is the Flamsteed designation. It has an apparent visual magnitude of 5.02, making it a faint star visible to the naked eye. The distance to 4 Aql can be estimated from its annual parallax shift of 6.7 mas, yielding an estimated range of around 480 light years. It is moving closer to the Earth with a heliocentric radial velocity of −13 km/s.

<span class="mw-page-title-main">21 Aquilae</span> Star in the constellation Aquila

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 about 5.1. The star is located at a distance of around 680 light-years from Earth, give or take a 20 light-year margin of error. It is moving closer to the Earth with a heliocentric radial velocity of –5 km/s.

14 Aquilae is a probable spectroscopic binary star system in the equatorial constellation of Aquila. 14 Aquilae is the Flamsteed designation though it also bears the Bayer designation g Aquilae. It is visible to the naked eye as a dim, white-hued star with an apparent visual magnitude of 5.42, and it is located at a distance of approximately 500 light-years from Sun. The star is moving closer to the Earth with a heliocentric radial velocity of −39 km/s, and may come as close as 136 light-years in around 3.5 million years.

66 Aquilae, abbreviated 66 Aql, is a fifth-magnitude star in the constellation of Aquila. 66 Aquilae is its Flamsteed designation. It is visible to the naked eye, having an apparent visual magnitude of 5.44. The star shows an annual parallax shift of 4.4 mas, which provides a distance estimate of around 730 light years. It is moving closer to the Earth with a heliocentric radial velocity of −30 km/s. The motion of the star over time suggests some displacement, which may indicate it is a close binary system.

42 Aquilae, abbreviated 42 Aql, is a single star in the equatorial constellation of Aquila. 42 Aquilae is its Flamsteed designation. It is a dim star but visible to the naked eye under suitable viewing conditions, having an apparent visual magnitude of 5.45. 42 Aql is located some 104.6 light years away, as determined from its annual parallax shift of 31.2 mas. it is moving closer to the Earth with a heliocentric radial velocity of −38 km/s, and is predicted to come to within 52 light-years of the Sun in around 752,000 years.

<span class="mw-page-title-main">28 Aquilae</span> Star in the constellation Aquila

28 Aquilae, abbreviated 28 Aql, is a star in the equatorial constellation of Aquila. 28 Aquilae is its Flamsteed designation though it also bears the Bayer designation A Aquilae, and the variable star designation V1208 Aquilae. It has an apparent visual magnitude is 5.5, making this a faint star that requires dark suburban skies to view. The annual parallax shift of 9.6 mas means this star is located at a distance of approximately 340 light-years from Earth.

22 Aquilae, abbreviated 22 Aql, is a star in the equatorial constellation of Aquila. 22 Aquilae is its Flamsteed designation. It is a faint star but visible to the naked eye with an apparent visual magnitude of 5.59. The distance to 22 Aql can be estimated from its annual parallax shift of 4.74 mas, which yields a separation of 690 light years. It is moving closer to the Earth with a heliocentric radial velocity of −23 km/s.

58 Aquilae is a single star located around 520 light years from the Sun in the equatorial constellation of Aquila, near Eta Aquilae. 58 Aquilae is its Flamsteed designation. It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude of 5.60. This object is moving closer to the Earth with a heliocentric radial velocity of −53 km/s, and may come as close as 161 light-years in around 1.8 million years.

62 Aquilae is a single star located about 427 light years away from the Sun in the equatorial constellation of Aquila. 62 Aquilae is its Flamsteed designation. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.67.

64 Aquilae, abbreviated 64 Aql, is a star in the equatorial constellation of Aquila. 64 Aquilae is its Flamsteed designation. It is a faint star that requires good viewing conditions to see, having an apparent visual magnitude of 5.97. The distance to 64 Aql, as determined from its annual parallax shift of 21.42 mas, is 152.2 light years. At that distance, the visual magnitude of the star is diminished by an extinction of 0.029 due to interstellar dust. It is moving closer to the Earth with a heliocentric radial velocity of −3.6 km/s.

8 Aquilae is a star in the equatorial constellation of Aquila, located 271 light years away from the Sun. 8 Aquilae is the Flamsteed designation. It can be viewed with the naked eye in good seeing conditions, appearing as a dim, yellow-white hued star with an apparent visual magnitude of 6.08. The star is moving further from the Earth with a heliocentric radial velocity of +12 km/s.

45 Aquilae, abbreviated 45 Aql, is a triple star system in the equatorial constellation of Aquila. 45 Aquilae is its Flamsteed designation. It is located 350 light-years away from Earth, give or take a 6 light-year margin of error, and has a combined apparent visual magnitude of 5.7. The system is moving closer to the Earth with a heliocentric radial velocity of -46 km/s.

<span class="mw-page-title-main">V923 Aquilae</span> Binary star system in the constellation Aquila

V923 Aquilae is a variable binary star system in the equatorial constellation of Aquila. It has the designation HD 183656 from the Henry Draper Catalogue; V932 Aql is the variable star designation. The system is dimly visible to the naked eye with an apparent visual magnitude that fluctuates around 6.06. It is located at a distance of approximately 890 light years from the Sun based on parallax, but is drifting closer with a radial velocity of around −26 km/s.

Psi Eridani, Latinized from ψ Eridani, is a star in the constellation Eridanus. With an apparent visual magnitude is 4.81, it can be seen with the naked eye on a clear, dark night. Based upon an annual parallax shift of 4.41 milliarcseconds, it is located roughly 740 light-years away from the Sun.

<span class="mw-page-title-main">HD 28375</span> Star in the constellation Taurus

HD 28375 is a single star in the equatorial constellation of Taurus, near the southern constellation border with Eridanus. It was previously known by the Flamsteed designation 44 Eridani, although the name has fallen out of use because constellations were redrawn, placing the star out of Eridanus and into Taurus. The star is blue-white in hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.53. The distance to this star is approximately 480 light-years based on parallax. It is drifting further away with a radial velocity of 18 km/s, after having come to within an estimated 249 light-years some 3.7 million years ago.

References

  1. ↑ "Hipparcos Tools Interactive Data Access". Hipparcos. ESA. Retrieved 8 December 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 .
  3. 1 2 3 4 5 Hohle, M. M.; et al. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten, 331 (4): 349, arXiv: 1003.2335 , Bibcode:2010AN....331..349H, doi:10.1002/asna.200911355, S2CID   111387483.
  4. 1 2 3 4 Bragança, G. A.; et al. (November 2012), "Projected Rotational Velocities and Stellar Characterization of 350 B Stars in the Nearby Galactic Disk", The Astronomical Journal, 144 (5): 10, arXiv: 1208.1674 , Bibcode:2012AJ....144..130B, doi:10.1088/0004-6256/144/5/130, S2CID   118868235, 130.
  5. 1 2 Buscombe, W. (1962), "Spectral classification of Southern fundamental stars", Mount Stromlo Observatory Mimeogram, 4: 1, Bibcode:1962MtSOM...4....1B.
  6. 1 2 Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
  7. 1 2 Gontcharov, G. A. (2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv: 1606.08053 , Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID   119231169.
  8. ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv: 1108.4971 , Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID   119257644.
  9. 1 2 3 4 Tetzlaff, N.; et al. (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.
  10. ↑ "20 Aql". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved October 29, 2018.
  11. ↑ Lefèvre, L.; Marchenko, S. V.; Moffat, A. F. J.; Acker, A. (2009), "A systematic study of variability among OB-stars based on HIPPARCOS photometry", Astronomy and Astrophysics, 507 (2): 1141–1201, Bibcode:2009A&A...507.1141L, doi: 10.1051/0004-6361/200912304 , ISSN   0004-6361.
  12. ↑ Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, GCVS 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID   125853869.
  13. ↑ Lesh, Janet Rountree (December 1968), "The Kinematics of the Gould Belt: an Expanding Group?", Astrophysical Journal Supplement, 17: 371, Bibcode:1968ApJS...17..371L, doi: 10.1086/190179 .
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