74 Aquarii

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74 Aquarii
HIAqrLightCurve.png
A light curve for HI Aquarii, plotted from TESS data [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Aquarius
Right ascension 22h 53m 28.70492s [2]
Declination −11° 36′ 59.4532″ [2]
Apparent magnitude  (V)5.8 [3]
Characteristics
Spectral type B8IV/V [4] (B9pHgMn) [3] )
U−B color index −0.245 [5]
B−V color index −0.082 [5]
Variable type a2 CVn [3]
Astrometry
Proper motion (μ)RA: +21.539 [2]   mas/yr
Dec.: +2.282 [2]   mas/yr
Parallax (π)5.5008 ± 0.6556  mas [2]
Distance approx. 590  ly
(approx. 180  pc)
Absolute magnitude  (MV)−1.19 [6]
Orbit [7]
Primary74 Aquarii A
Companion74 Aquarii B
Period (P)9.479±0.044 yr
Semi-major axis (a)0.0460±0.0061″
Eccentricity (e)0.862±0.029
Inclination (i)29.8±17.4°
Longitude of the node (Ω)40.9±20.3°
Periastron epoch (T)2010.039±0.134
Argument of periastron (ω)
(secondary)		70.7±16.1°
Orbit [8]
Primary74 Aquarii Aa
Companion74 Aquarii Ab
Period (P)3.429616±0.000004 d
Eccentricity (e)0.05±0.02
Periastron epoch (T)2452909.150±0.007  JD
Argument of periastron (ω)
(secondary)		86.5±0.8°
Semi-amplitude (K1)
(primary)		95±2 km/s
Semi-amplitude (K2)
(secondary)		113±2 km/s
Details
Aa
Mass 2.72 [9]   M☉
Rotational velocity (v sin i)20 [10]  km/s
Ab
Mass 2.53 [9]   M☉
B
Mass 3.11 [9]   M☉
Other designations
HI Aqr, BD–12 6371, HD 216494, HIP 113031, HR  8704, SAO 165359 [11]
Database references
SIMBAD data

74 Aquarii (abbreviated 74 Aqr) is a triple star [12] system in the constellation of Aquarius. 74 Aquarii is its Flamsteed designation and it also bears the variable star designation HI Aquarii. The combined apparent visual magnitude is 5.8, [5] although it is very slightly variable, [3] and it is located at a distance of 590 light-years (180 parsecs ) from Earth.

Contents

Jean Manfroid and Gautier Mathys reported that 74 Aquarii is a variable star in 1985. [13] Based on that result it was given its variable star designation in 1987. [14]

Visual binary

74 Aquarii is a double star with the two components separated by about 0.1″ . [15] The two components are referred to as A and B or AB and C in different publications. [7] [8] The pair form a binary with a period of 9.5 years at a typical angular separation of 0.046″, but the orbit is highly eccentric. [7] In 2010, this component was at an angular separation of 0.069  arcseconds along a position angle of 285.9°. This is equivalent to a projected separation of 13.9±2.4  AU . [12]

Spectroscopic binary

The primary star of the visual pair is a double-lined spectroscopic binary, where the presence of both components is revealed from the Doppler shift of their spectral lines, meaning 74 Aquarii is a triple system. The spectroscopic binary was discovered and the orbit calculated by Richard J. Wolff of the University of Hawaii in 1974. [16] A refined orbit was calculated in 2004 by Italian astronomers Giovanni Catanzaro and Paolo Leto in 2004. The orbital period is 3.4 days and the orbit is nearly circular. [8]

Components

The three stars have a combined spectral type of B8 or B9 and all three are thought to be similar. It is unclear whether the stars are on the main sequence, subgiants, or giant stars. [9] [17] [4] The two visual components are both chemically peculiar stars, the brighter of the two being a mercury-manganese star and the fainter an Ap/Bp star with an excess of mercury. [15] 74 Aquarii is an a2 CVn variable star, with a total amplitude of just 0.01 magnitudes, [3] and a period of 3.5892 days. [18]

Related Research Articles

<span class="mw-page-title-main">Delta Aquarii</span> Star in the constellation Aquarius

Delta Aquarii, officially named Skat, is the third-brightest star in the constellation of Aquarius. The apparent visual magnitude is 3.3, which can be seen with the naked eye. The distance to this star is about 113 light-years based upon parallax measurements, and it has a close companion.

<span class="mw-page-title-main">Beta Aquarii</span> Double star in the constellation Aquarius

Beta Aquarii is a single yellow supergiant star in the constellation of Aquarius. It has the official name Sadalsuud and the Bayer designation β Aquarii, abbreviated Beta Aqr or β Aqr. Based upon parallax measurements obtained during the Hipparcos mission, this component is located at a distance of approximately 540 light years (165 parsecs) from the Sun. It is drifting further away with a radial velocity of 6.5 km/s. The star serves as an IAU radial velocity standard.

Tau<sup>2</sup> Aquarii Star in the constellation Aquarius

Tau2 Aquarii, Latinized from τ2 Aquarii, is the Bayer designation for a single star in the equatorial constellation of Aquarius. It is visible to the naked eye with an apparent visual magnitude of +4.0. Because the star lies near the ecliptic it is subject to occultations by the Moon. The star is located at a distance of approximately 318 light years from the Sun based on parallax.

<span class="mw-page-title-main">Sigma Aquarii</span> Star in the constellation Aquarius

Sigma Aquarii, Latinized from σ Aquarii, is a double star in the equatorial constellation of Aquarius, positioned about 1.3° to the south of the ecliptic. Due to its proximity to the ecliptic, this star is subject to occultation by the Moon. It has a white hue and is visible to the naked eye with an apparent visual magnitude of 4.81. Based upon parallax measurements, the distance to this star is approximately 175 light-years. It is drifting further away with a radial velocity of +11 km/s.

<span class="mw-page-title-main">Chi Aquarii</span> Star in the constellation Aquarius

Chi Aquarii, Latinized from χ Aquarii, is the Bayer designation of a star in the equatorial constellation of Aquarius. The distance to this star, based upon parallax measurements with a 7% margin of error, is roughly 610 light-years. It is visible to the naked eye with an apparent visual magnitude of about 5.

<span class="mw-page-title-main">Rho Aquarii</span> Star in the constellation Aquarius

Rho Aquarii, Latinized from ρ Aquarii, is the Bayer designation for a binary star system in the equatorial constellation of Aquarius. It is visible to the naked eye with an apparent visual magnitude of +5.34. Based upon parallax measurements, this star is at a distance of roughly 870 light-years from Earth. It is drifting closer with a radial velocity of –9 km/s. The proximity of this star to the ecliptic means it is subject to lunar occultations.

<span class="mw-page-title-main">63 Andromedae</span> Star in the constellation Andromeda

63 Andromedae is an Alpha2 Canum Venaticorum variable star in the constellation Andromeda. Its variable star designation is PZ Andromedae. With an apparent magnitude of about 5.6, it is bright enough to be seen by naked eye. Based upon an annual parallax shift of 8.53 mas, it is located 382 light years away.

32 Aquarii is a binary star system in the zodiac constellation of Aquarius. 32 Aquarii is its Flamsteed designation. It is visible to the naked eye as a dim, white-hued star with an apparent visual magnitude of 5.29. This system is moving away from the Earth with a heliocentric radial velocity of +19 km/s, and is a possible member of the corona of the Ursa Major flow.

7 Aquarii, abbreviated 7 Aqr, is a binary star system in the zodiac constellation of Aquarius. 7 Aquarii is the Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 5.5; the brighter component is baseline magnitude 5.62 while the faint secondary is magnitude 11.4. As of 2002, the pair had an angular separation of 2.10″ along a position angle of 165°. The distance to this system, based upon an annual parallax shift of 4.9 mas, is around 660 light years. It is moving closer to the Earth with a heliocentric radial velocity of −32 km/s.

5 Aquarii is a single star in the zodiac constellation of Aquarius, located about 830 light years away from the Sun, based on parallax. 5 Aquarii is the Flamsteed designation. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 5.55. This object is moving closer to the Earth with a heliocentric radial velocity of −3 km/s.

<span class="mw-page-title-main">70 Aquarii</span> Star in the constellation Aquarius

70 Aquarii is a variable star located 425 light years away from the Sun in the equatorial constellation of Aquarius. It has the variable star designation FM Aquarii; 70 Aquarii is the Flamsteed designation. It is near the lower limit of visibility to the naked eye, appearing as a dim, yellow-white hued star with a baseline apparent visual magnitude of 6.19. This star is moving closer to the Earth with a heliocentric radial velocity of –5.8 km/s.

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

Kappa Cancri, Latinized from κ Cancri, is a blue-white hued binary star system in the zodiac constellation of Cancer. It is faintly visible to the naked eye with an apparent visual magnitude of +5.23. The magnitude difference between the two stars is about 2.6. Based upon an annual parallax shift of 5.3209 mas as seen from the Earth, the system is located roughly 610 light-years from the Sun.

<span class="mw-page-title-main">15 Cancri</span> Star in the constellation Cancer

15 Cancri is an α2 CVn-type variable star in the zodiac constellation of Cancer, located around 980 light years away. It has the variable star designation BM Cancri ; 15 Cancri is the Flamsteed designation. This system is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of about 5.6. It is moving away from the Earth with a heliocentric radial velocity of 25 km/s.

<span class="mw-page-title-main">R Aquarii</span> Star in the constellation of Aquarius

R Aquarii is a variable star in the constellation Aquarius.

<span class="mw-page-title-main">EZ Canis Majoris</span> Binary star system in the constellation Canis Major

EZ Canis Majoris is binary system in the constellation of Canis Major. The primary is a Wolf-Rayet star and it is one of the ten brightest Wolf-Rayet stars, brighter than apparent magnitude 7.

<span class="mw-page-title-main">LP Aquarii</span> Star in the constellation Aquarius

LP Aquarii is a pulsating variable star in the constellation of Aquarius that varies between magnitudes 6.30 and 6.64. The position of the star near the ecliptic means it is subject to lunar occultations.

8 Aquarii is a blue-white sub-giant of the spectral class A4IV in the constellation Aquarius. 8 Aquarii is the Flamsteed designation. It is approximately 298 light-years away from Earth, based on parallax. It is approximately 1.7 solar masses and about 3 times hotter than the Sun and thus allows lines of ionized metals with an abundance of metals.

<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">EP Aquarii</span> Variable star in the constellation Aquarius

EP Aquarii is a semiregular variable star in the equatorial constellation of Aquarius. At its peak brightness, visual magnitude 6.37, it might be faintly visible to the unaided eye under ideal observing conditions. A cool red giant on the asymptotic giant branch (AGB), its visible light brightness varies by about 1/2 magnitude over a period of 55 days. EP Aquarii has a complex circumstellar envelope (CSE), which has been the subject of numerous studies.

<span class="mw-page-title-main">HD 27563</span> Star in the constellation Eridanus

HD 27563, also known by the Bayer designation d Eridani, is a single star in Eridanus, in the direction of the Orion–Eridanus Superbubble, that is faintly visible to the naked eye at a magnitude of about 5.84. Cowley (1972) classifies this star as spectral type B5III, but Houk and Swift (1999) catalog it as B7II.

References

  1. ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
  2. 1 2 3 4 5 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  3. 1 2 3 4 5 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: B/gcvs, Bibcode:2009yCat....102025S.
  4. 1 2 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.
  5. 1 2 3 Gutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile, 1, Publicaciones Universidad de Chile, Department de Astronomy: 1–17, Bibcode:1966PDAUC...1....1G.
  6. ↑ 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.
  7. 1 2 3 Tokovinin, Andrei (2017), "New Orbits Based on Speckle Interferometry at SOAR. II", The Astronomical Journal, 154 (3), 110, arXiv: 1708.01300 , Bibcode:2017AJ....154..110T, doi: 10.3847/1538-3881/aa8459 , S2CID   118429576.
  8. 1 2 3 Catanzaro, G.; Leto, P. (2004), "Orbital solutions for SB2 systems with a HgMn component", Astronomy and Astrophysics, 416 (2): 661–668, Bibcode:2004A&A...416..661C, doi: 10.1051/0004-6361:20034445 .
  9. 1 2 3 4 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.
  10. ↑ Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi: 10.1086/340590 .
  11. ↑ "* 74 Aqr", SIMBAD , Centre de données astronomiques de Strasbourg , retrieved 2012-07-01.
  12. 1 2 Schöller, M.; et al. (November 2010), "Multiplicity of late-type B stars with HgMn peculiarity", Astronomy and Astrophysics, 522: A85, arXiv: 1010.3643 , Bibcode:2010A&A...522A..85S, doi:10.1051/0004-6361/201014246, S2CID   119273467.
  13. ↑ Manfroid, J.; Mathys, G. (March 1985). "New period determinations for variable CP stars". Astronomy and Astrophysics Supplement Series. 59: 429–432. Bibcode:1985A&AS...59..429M . Retrieved 19 November 2024.
  14. ↑ Kholopov, P. N.; Samus, N. N.; Kazarovets, E. V.; Kireeva, N.N. (August 1987). "The 68th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 3058: 1–30. Bibcode:1987IBVS.3058....1K . Retrieved 19 November 2024.
  15. 1 2 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. ↑ Wolff, Richard J (1974), "Orbit of the Manganese Star HR 8704", Publications of the Astronomical Society of the Pacific, 86 (510): 173–175, Bibcode:1974PASP...86..173W, doi: 10.1086/129576 .
  17. ↑ Skiff, B. A. (2014), "VizieR Online Data Catalog: Catalogue of Stellar Spectral Classifications (Skiff, 2009- )", VizieR On-line Data Catalog, Bibcode:2014yCat....1.2023S.
  18. ↑ "HI Aqr". The International Variable Star Index. AAVSO. Retrieved 5 December 2022.
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