17 Aquarii

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17 Aquarii
Observation data
Epoch J2000       Equinox J2000
Constellation Aquarius
Right ascension 21h 22m 56.25866s [1]
Declination −09° 19′ 09.5823″ [1]
Apparent magnitude  (V)5.99 [2]
Characteristics
Spectral type K4/5 III [3]
B−V color index 1.516±0.008 [2]
Astrometry
Radial velocity (Rv)18.2±2.9 [4]  km/s
Proper motion (μ)RA: −29.659 [1]   mas/yr
Dec.: −29.022 [1]   mas/yr
Parallax (π)4.9125 ± 0.1260 [1]   mas
Distance 660 ± 20  ly
(204 ± 5  pc)
Absolute magnitude  (MV)−0.73 [2]
Orbit [5]
Period (P)7,290 d
Eccentricity (e)0.4
Details
17 Aqr A
Luminosity 495.46 [2]   L☉
Surface gravity (log g)1.74±0.14 [6]   cgs
Temperature 3,951±14 [6]   K
Metallicity [Fe/H]−0.10±0.06 [6]   dex
Other designations
BD−09° 5728, FK5  3705, HD  203525, HIP  105574, HR  8175, SAO  145351 [7]
Database references
SIMBAD data

17 Aquarii, abbreviated 17 Aqr, is a spectroscopic binary [5] star system in the constellation of Aquarius. 17 Aquarii is the Flamsteed designation. It appears to the naked eye as a faint sixth magnitude star, having a combined apparent visual magnitude of 5.99. [2] The distance to 17 Aqr can be estimated from its annual parallax shift of 4.9  mas , [1] which yields a separation of around 660  light years. It is moving further away with a heliocentric radial velocity of 18 km/s. [4]

Star sphere of plasma held together by gravity, undergoing fusion; type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity

A star is type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye from Earth during the night, appearing as a multitude of fixed luminous points in the sky due to their immense distance from Earth. Historically, the most prominent stars were grouped into constellations and asterisms, the brightest of which gained proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. However, most of the estimated 300 sextillion (3×1023) stars in the Universe are invisible to the naked eye from Earth, including all stars outside our galaxy, the Milky Way.

Constellation one of the 88 divisions of the celestial sphere, defined by the IAU, many of which derive from traditional asterisms

A constellation is a group of stars that forms an imaginary outline or pattern on the celestial sphere, typically representing an animal, mythological person or creature, a god, or an inanimate object.

Aquarius (constellation) zodiac constellation straddling the celestial equator

Aquarius is a constellation of the zodiac, situated between Capricornus and Pisces. Its name is Latin for "water-carrier" or "cup-carrier", and its symbol is , a representation of water. Aquarius is one of the oldest of the recognized constellations along the zodiac. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. It is found in a region often called the Sea due to its profusion of constellations with watery associations such as Cetus the whale, Pisces the fish, and Eridanus the river.

A preliminary orbit for the pair gives a period of 20 years and an eccentricity of 0.4. [5] The primary component is an aging giant star with a stellar classification of K4/5 III. [3] It is radiating 495 [2] times the Sun's luminosity from its photosphere at an effective temperature of 3,951 K. [6]

The orbital period is the time a given astronomical object takes to complete one orbit around another object, and applies in astronomy usually to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars.

Orbital eccentricity parameter that determines the amount by which an orbit deviates from a perfect circle

The orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values between 0 and 1 form an elliptic orbit, 1 is a parabolic escape orbit, and greater than 1 is a hyperbola. The term derives its name from the parameters of conic sections, as every Kepler orbit is a conic section. It is normally used for the isolated two-body problem, but extensions exist for objects following a Klemperer rosette orbit through the galaxy.

Giant star type of star with a radius 10-100 times, and luminosity 10-1000x that of the Sun

A giant star is a star with substantially larger radius and luminosity than a main-sequence star of the same surface temperature. They lie above the main sequence on the Hertzsprung–Russell diagram and correspond to luminosity classes II and III. The terms giant and dwarf were coined for stars of quite different luminosity despite similar temperature or spectral type by Ejnar Hertzsprung about 1905.

Related Research Articles

R Hydrae Variable star in the constellation Hydra

R Hydrae, also known as R Hya, is a Mira-type variable star in the constellation Hydra.

Phi Aquarii Star in the constellation Aquarius

Phi 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 +4.223. Parallax measurements from the Hipparcos mission indicate its estimated distance from Earth is roughly 220 light-years.

47 Aquarii, abbreviated 47 Aqr, is a star in the zodiac constellation of Aquarius. 47 Aquarii is its Flamsteed designation. It is a faint star but visible to the naked eye in good seeing conditions, having an apparent visual magnitude of 5.135. Based upon an annual parallax shift of 18.0 mas, it is located 181 light years away. At that distance, the visual magnitude of the star is diminished by an extinction of 0.088 due to interstellar dust. It is moving further from the Earth with a heliocentric radial velocity of +48 km/s.

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.

12 Aquarii is a double star in the constellation Aquarius. 12 Aquarii is the Flamsteed designation. It consists of a K-type giant and an A-type main-sequence star. Parallax measurements by Hipparcos put it at a distance of some 500 light-years, or 150 parsecs away.

49 Aquarii, abbreviated 49 Aqr, is a star in the zodiac constellation of Aquarius. 49 Aquarii is its Flamsteed designation. It is a dim star with an apparent visual magnitude of 5.53. The distance to 49 Aqr, as determined from its annual parallax shift of 12.28 mas, is 266 light years. It is moving closer to the Earth with a heliocentric radial velocity of −13 km/s.

19 Aquarii is a star in the constellation of Aquarius. With an apparent magnitude of about 5.7, the star is barely visible to the naked eye. Parallax estimates made by the Hipparcos spacecraft put it at a distance of about 300 light years away from the Earth.

50 Aquarii, abbreviated 50 Aqr, is a single star in the zodiac constellation of Aquarius. 50 Aquarii is its Flamsteed designation. It is a faint star with an apparent visual magnitude of 5.76 that is barely visible to the naked eye under good seeing conditions. The star is located near the ecliptic and thus is subject to lunar occultations. Based upon an annual parallax shift of 12.2 mas as seen from Earth orbit, it is located 266 light years away. It is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.

15 Aquarii, abbreviated 15 Aqr, is a single, blue-white star in the zodiac constellation of Aquarius. 15 Aquarii is the Flamsteed designation. It is a dim star that is just visible to the naked eye under good viewing conditions, having an apparent visual magnitude of 5.83. Based upon an annual parallax shift of 4.6 mas, it is located around 710 light years away. At that distance, the visual magnitude is diminished by an extinction of 0.18 due to interstellar dust. It is moving closer to the Earth with a heliocentric radial velocity of −9 km/s. Relative to its neighbors, 15 Aqr has a peculiar velocity of 28.7+2.9
−3.1 km/s and may be a runaway star.

16 Aquarii, abbreviated 16 Aqr, is a star in the constellation of Aquarius. 16 Aquarii is the Flamsteed designation. It is a faint star, just visible to the naked eye, with an apparent visual magnitude of 5.869. Based upon an annual parallax shift of 9.5 mas, it is located about 342 light years away. It is moving closer to the Earth with a heliocentric radial velocity of −6 km/s, and is predicted to come within 220 light-years in 6.8 million years.

56 Aquarii, abbreviated 56 Aqr, is a star in the constellation of Aquarius. 56 Aquarii is its Flamsteed designation. It is a sixth magnitude star, having an apparent visual magnitude of 6.36, and thus is a challenge to view with the naked eye. Based upon an annual parallax shift of 5.07 mas, it is located around 643 light years from the Earth. At that distance, the visual magnitude is diminished by an extinction of 0.12 due to interstellar dust. The star is moving closer with a heliocentric radial velocity of −28 km/s. It is a candidate runaway star showing a transverse peculiar velocity of 213.87 km/s.

20 Aquarii, abbreviated 20 Aqr, is a star in the constellation Aquarius. 20 Aquarii is the Flamsteed designation. It is a dim star with an apparent visual magnitude of 6.38. Based upon an annual parallax shift of 15.34 mas, it is located 213 light years away but is moving closer to the Earth with a heliocentric radial velocity of −23 km/s. The star is predicted to come to within 110 light-years in around 1.9 million years.

61 Aquarii, abbreviated 61 Aqr, is an orange-hued star in the zodiac constellation of Aquarius. 61 Aquarii is its Flamsteed designation. It has an apparent visual magnitude of 6.39, which indicates it is a dim star that requires good seeing conditions to view. Based upon an annual parallax shift of 6.53 mas as seen from Earth's orbit, the star is located around 500 light years away. It is moving closer to the Earth with a heliocentric radial velocity of −8 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.

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.

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.

62 Aquilae, abbreviated 62 Aql, is a single star in the equatorial constellation of Aquila. 62 Aquilae is its Flamsteed designation. Its apparent magnitude is 5.67.

4 Aquarii is a binary star in the constellation Aquarius. 4 Aquarii is the Flamsteed designation. Located approximately 60.72 parsecs (198.0 ly) distant, the combined apparent magnitude of the system is 5.99. The spectral type of the primary star is F5IV-V, meaning that it is either a subgiant or a main-sequence star of spectral type F.

40 Aquarii is a yellow subgiant in the constellation of Aquarius. 40 Aquarii is its Flamsteed designation. It is approximately 720 light-years from Earth, based on its parallax.

64 Aquarii, abbreviated 64 Aqr, is a star in the zodiac constellation of Aquarius. 64 Aquarii is its Flamsteed designation. Its apparent magnitude is 6.95.

References

  1. 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 .
  2. 1 2 3 4 5 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.
  3. 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.
  4. 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.
  5. 1 2 3 Famaey, B.; et al. (2009). "Spectroscopic binaries among Hipparcos M giants,. I. Data, orbits, and intrinsic variations". Astronomy and Astrophysics. 498 (2): 627–640. arXiv: 0901.0934 . Bibcode:2009A&A...498..627F. doi:10.1051/0004-6361/200810698.
  6. 1 2 3 4 Wu, Yue; et al. (2010). "Coudé-feed stellar spectral library – atmospheric parameters". Astronomy & Astrophysics. 525: A71. arXiv: 1009.1491 . Bibcode:2011A&A...525A..71W. doi:10.1051/0004-6361/201015014.
  7. ↑ "17 Aqr". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved October 22, 2018.
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