21 Aquilae

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21 Aquilae
V1288AqlLightCurve.png
An ultraviolet band light curve for V1288 Aquilae, adapted from Veto (1980) [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Aquila
Right ascension 19h 13m 42.70120s [2]
Declination +02° 17′ 37.3103″ [2]
Apparent magnitude  (V)5.06 - 5.16 [3]
Characteristics
Spectral type B8II-III(Hg?) [4]
U−B color index −0.399 [5]
B−V color index −0.065 [5]
Variable type α2 CVn [3]
Astrometry
Radial velocity (Rv)−5.2 [6]  km/s
Proper motion (μ)RA: +10.102 [2]   mas/yr
Dec.: −0.825 [2]   mas/yr
Parallax (π)4.7730 ± 0.1052  mas [2]
Distance 680 ± 20  ly
(210 ± 5  pc)
Absolute magnitude  (MV)−2.12 [7]
Details
Mass 6.7 [8]   M☉
Radius 6.2 [9]   R☉
Luminosity 704 [8]   L☉
Surface gravity (log g)3.95 [8]   cgs
Temperature 12,014 [8]   K
Metallicity [Fe/H]−0.20 [10]   dex
Rotation 9.3  d [11]
Rotational velocity (v sin i)17 [10]  km/s
Age 165 [12]   Myr
Other designations
21 Aql, V1288 Aql, BD+02°3824, FK5  3537, HD  179761, HIP  94477, HR  7287, SAO  124408, WDS J19137+0218A [13]
Database references
SIMBAD data

21 Aquilae is a solitary [14] 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 (210 parsecs ) 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. [6]

The stellar classification of this star is B8 II-III, with the luminosity class of II-III suggesting that the spectrum displays elements of both a giant star and a bright giant. It is a chemically peculiar star of the Mercury-Manganese type (CP3), [10] although some catalogues consider that status to be doubtful. [15] This is a probable Alpha2 Canum Venaticorum variable that ranges in visual magnitude from 5.06 down to 5.16. [3] The star is radiating 704 times the luminosity of the Sun from its photosphere at an effective temperature of 12,014  K ; this gives it the blue-white glow of a B-type star. [16]

21 Aquilae is catalogued as an optical double star, having a 12th magnitude companion 37″ away as of 2010. It was first identified as a double star by John Herschel. [17] The companion is a distant background object. [18]

Related Research Articles

<span class="mw-page-title-main">V1494 Aquilae</span> Nova seen in 1999 in the constellation of Aquila

V1494 Aquilae or Nova Aquilae 1999 b was a nova which occurred during 1999 in the constellation Aquila and reached a brightness of magnitude 3.9 on 2 December 1999. making it easily visible to the naked eye. The nova was discovered with 14×100 binoculars by Alfredo Pereira of Cabo da Roca, Portugal at 18:50 UT on 1 December 1999, when it had a visual magnitude of 6.0.

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

Nu Aquilae, Latinized from ν Aquilae, is the Bayer designation for a double star in the constellation of Aquila that lies close to the celestial equator. It has an apparent visual magnitude of 4.72 and so is visible to the naked eye. Based upon an annual parallax shift of only 0.8752 mas, it is believed to lie approximately 3,700 light-years from Earth. The variable star NU Aquilae has a similar-looking designation but is a separate and unrelated object.

<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">Phi Aquilae</span> Binary star system in the constellation Aquila

Phi Aquilae, Latinized from φ Aquilae, is the Bayer designation of a binary star system in the equatorial constellation of Aquila. It has an apparent visual magnitude of +5.28 and is visible to the naked eye. With an annual parallax shift of 14.198 mas, this star is located at a distance of approximately 230 light-years from Earth. It is drifting closer with a radial velocity of –27 km/s. Based on its motion through space, this system is considered a possible member of the nearby Argus association of co-moving stars, although it may be too old.

<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.

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

Psi Aquilae, Latinized as ψ Aquilae, is the Bayer designation for a star in the equatorial constellation of Aquila. It is a faint star with an apparent visual magnitude of 6.25, which, according to the Bortle Dark-Sky Scale, can be seen with the naked eye in dark rural skies. The orbit of the Earth causes an annual parallax shift of 2.83 mas, which indicates a distance of approximately 1,150 light-years.

<span class="mw-page-title-main">8 Andromedae</span> Mulitple star system in the constellation Andromeda

8 Andromedae, abbreviated 8 And, is a probable triple star system in the northern constellation of Andromeda. 8 Andromedae is the Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 4.82. Based upon an annual parallax shift of 5.7 mas, it is located about 570 light years from the Earth. It is moving closer with a heliocentric radial velocity of −8 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.

<span class="mw-page-title-main">20 Aquilae</span> Star in the constellation Aquila

20 Aquilae, abbreviated 20 Aql, is an irregular variable 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. The estimated distance to this star is around 920 light years, based upon an annual parallax shift of 3.5 mas. The star is moving closer to the Earth with a heliocentric radial velocity of −23 km/s.

<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.

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.

<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.

<span class="mw-page-title-main">V1291 Aquilae</span> Variable star in the constellation Aquila

V1291 Aquilae is a single star in the equatorial constellation of Aquila. It has a yellow-white hue and is dimly visible to the naked eye with an apparent visual magnitude that fluctuates around 5.65. Based on parallax measurements, it is located at a distance of approximately 278 light years from the Sun. The star it is drifting closer with a radial velocity of −22 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.

46 Aquilae is a star in the constellation of Aquila, located to the north of Tarazed. 46 Aquilae is its Flamsteed designation. It is a dim, blue-white hued star that is a challenge to view with the naked eye, having an apparent visual magnitude of 6.33. This object is located approximately 830 light years from the Sun, based on parallax. It is moving closer to the Earth with a heliocentric radial velocity of −25 km/s.

HD 102350 is a single star in the constellation Centaurus. It has a yellow hue and is visible to the naked eye with an apparent visual magnitude of 4.11. The distance to this star is approximately 390 light years based on parallax, but it is drifting closer with a radial velocity of −3 km/s. It has an absolute magnitude of −1.51.

<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.

<span class="mw-page-title-main">8 Leonis Minoris</span> Star in the constellation of Leo Minor

8 Leonis Minoris is a solitary, red hued star located in the northern constellation Leo Minor. It has an apparent magnitude 5.37, making it faintly visible to the naked eye. Based on parallax measurements from the Gaia satellite, the object is estimated to be 492 light years distant. It is receding with a heliocentric radial velocity of 40 km/s. At its current distance, 8 LMi is diminshed by 0.12 magnitudes due to interstellar dust.

<span class="mw-page-title-main">PW Telescopii</span> Α2 CVn variable; Telescopium

PW Telescopii, also known as HD 183806 or simply PW Tel, is a solitary variable star located in the southern constellation Telescopium. It has an average apparent magnitude of 5.58, making it faintly visible to the naked eye. Based on parallax measurements from the Gaia satellite, the star is estimated to be 395 light years distant. It appears to be approaching the Solar System with a heliocentric radial velocity of −10 km/s. The value is somewhat constrained, having an uncertainty of 26%. At its current distance, PW Tel's brightness is diminished by 0.05 magnitudes due to interstellar dust.

References

  1. ↑ Veto, B. (May 1980). "Ultraviolet Observations of the Silicon Star HD 179761". Information Bulletin on Variable Stars. 1778 (1). Bibcode:1980IBVS.1778....1V.
  2. 1 2 3 4 5 Vallenari, A.; et al. (Gaia Collaboration) (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics . arXiv: 2208.00211 . doi: 10.1051/0004-6361/202243940 . Gaia DR3 record for this source at VizieR.
  3. 1 2 3 Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID   125853869.
  4. ↑ Cowley, A. (November 1972). "Spectral classification of the bright B8 stars". Astronomical Journal. 77: 750–755. Bibcode:1972AJ.....77..750C. doi:10.1086/111348.
  5. 1 2 Stepien, K. (December 1968). "Photometric behavior of magnetic stars". Astrophysical Journal. 154: 945. Bibcode:1968ApJ...154..945S. doi:10.1086/149815.
  6. 1 2 Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.). Proceedings from IAU Symposium no. 30. Determination of Radial Velocities and their Applications. Vol. 30. University of Toronto: International Astronomical Union. p. 57. Bibcode:1967IAUS...30...57E.
  7. ↑ 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.
  8. 1 2 3 4 Fouesneau, M.; Andrae, R.; Dharmawardena, T.; Rybizki, J.; Bailer-Jones, C. A. L.; Demleitner, M. (2022). "Astrophysical parameters from Gaia DR2, 2MASS, and AllWISE". Astronomy and Astrophysics. 662: A125. arXiv: 2201.03252 . Bibcode:2022A&A...662A.125F. doi:10.1051/0004-6361/202141828. S2CID   245837778.
  9. ↑ Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (20 December 2021). "Stellar and substellar companions from Gaia EDR3". Astronomy & Astrophysics. 657: A7. arXiv: 2109.10912 . Bibcode:2022A&A...657A...7K. doi: 10.1051/0004-6361/202142146 . eISSN   1432-0746. ISSN   0004-6361.
  10. 1 2 3 Ghazaryan, S.; et al. (November 2018). "New catalogue of chemically peculiar stars, and statistical analysis". Monthly Notices of the Royal Astronomical Society. 480 (3): 2953–2962. arXiv: 1807.06902 . Bibcode:2018MNRAS.480.2953G. doi:10.1093/mnras/sty1912. S2CID   119062018.
  11. ↑ Oelkers, Ryan J.; Rodriguez, Joseph E.; Stassun, Keivan G.; Pepper, Joshua; Somers, Garrett; Kafka, Stella; Stevens, Daniel J.; Beatty, Thomas G.; Siverd, Robert J.; Lund, Michael B.; Kuhn, Rudolf B.; James, David; Gaudi, B. Scott (2018). "Variability Properties of Four Million Sources in the TESS Input Catalog Observed with the Kilodegree Extremely Little Telescope Survey". The Astronomical Journal. 155 (1): 39. arXiv: 1711.03608 . Bibcode:2018AJ....155...39O. doi:10.3847/1538-3881/aa9bf4. S2CID   119515775.
  12. ↑ Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv: 1606.08814 . Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. ISSN   0320-0108. S2CID   118345778.
  13. ↑ "21 Aql". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-06-05.
  14. ↑ Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869. arXiv: 0806.2878 . Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID   14878976.
  15. ↑ Renson, P.; Manfroid, J. (May 2009). "Catalogue of Ap, HgMn and Am stars". Astronomy and Astrophysics. 498 (3): 961–966. Bibcode:2009A&A...498..961R. doi: 10.1051/0004-6361/200810788 .
  16. ↑ "The Colour of Stars". Australia Telescope, Outreach and Education. Commonwealth Scientific and Industrial Research Organisation. December 21, 2004. Archived from the original on March 18, 2012. Retrieved 2012-01-16.
  17. ↑ Mason, B. D.; et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi: 10.1086/323920 . Retrieved 2015-07-22.
  18. ↑ Vallenari, A.; et al. (Gaia Collaboration) (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics . arXiv: 2208.00211 . doi: 10.1051/0004-6361/202243940 . Gaia DR3 record for this source at VizieR.
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