25 Aquarii

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25 Aquarii
Aquarius IAU.svg
Cercle rouge 100%25.svg
Location of 25 Aquarii (circled)
Observation data
Epoch J2000       Equinox J2000
Constellation Aquarius
Right ascension 21h 39m 33.26758s [1]
Declination +02° 14 36.8173 [1]
Apparent magnitude  (V)+5.09 [2]
Characteristics
Spectral type K0 III [3]
U−B color index +0.90 [2]
B−V color index +1.032 [4]
Astrometry
Radial velocity (Rv)–34.63 ± 0.11 [4]  km/s
Proper motion (μ)RA: –29.55 [1]   mas/yr
Dec.: –83.22 [1]   mas/yr
Parallax (π)14.40 ± 0.30  mas [1]
Distance 226 ± 5  ly
(69 ± 1  pc)
Details
Radius 11 [4]   R
Luminosity 54 [4]   L
Surface gravity (log g)2.5 [4]   cgs
Temperature 4,721 [4]   K
Metallicity [Fe/H]–0.17 [4]   dex
Rotational velocity (v sin i)2.5 [4]  km/s
Other designations
d   Aquarii, 25  Aqr, 6  Pegasi, BD+01 4517, FK5  3729, HD  206067, HIP  106944, HR  8277, SAO  126965 [5]
Database references
SIMBAD data

25 Aquarii (abbreviated 25 Aqr) is a single [3] star in the equatorial constellation of Aquarius. 25 Aquarii is the modern Flamsteed designation; in the past it held the designation 6 Pegasi. [6] It also bears the Bayer designation of d Aquarii. It is located near the border with the modern Pegasus constellation. Although faint at an apparent visual magnitude of +5.09, [2] it is bright enough to be viewed from suburban skies. Based upon an annual parallax shift of 0.01440  arcseconds, [1] it is located at a distance of around 226 light-years (69 parsecs ) from Earth. The visual magnitude of the star is diminished by 0.09 from extinction caused by intervening gas and dust. [7]

The spectrum of this star matches a stellar classification of K0 III, [3] with the luminosity class of III indicating that this is a giant star that has evolved away from the main sequence after exhausting the supply of hydrogen at its core. It belongs to a population known as clump giants and hence is generating energy through the nuclear fusion of helium at the core. [8] The outer envelope has expanded to 11 times the radius of the Sun and it is radiating 54 times the Sun's luminosity. [4] This energy is being emitted from the stellar atmosphere at an effective temperature of 4,721 K, [4] causing it to glow with the orange hue of a K-type star. [9]

Related Research Articles

<span class="mw-page-title-main">98 Aquarii</span> Star in the constellation Aquarius

98 Aquarii is a star in the equatorial constellation of Aquarius. 98 Aquarii is the Flamsteed designation, although it also bears the Bayer designation b1 Aquarii. It is visible to the naked eye with an apparent visual magnitude of +3.97. The distance to this star, 163 light-years, is known from parallax measurements made with the Hipparcos spacecraft.

<span class="mw-page-title-main">91 Aquarii</span> Triple star system in the constellation Aquarius

91 Aquarii is the Flamsteed designation for a triple star system in the equatorial constellation of Aquarius. It also bears the Bayer designation Psi1 Aquarii. It is visible to the naked eye with an apparent visual magnitude of +4.248. Parallax measurements yield an estimated distance of around 150 light-years from Earth. An extrasolar planet is known to orbit the main star.

<span class="mw-page-title-main">66 Aquarii</span> Star in the constellation Aquarius

66 Aquarii is a single star in the equatorial constellation of Aquarius. 66 Aquarii is the Flamsteed designation though the star also bears the Bayer designation of g1 Aquarii. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.673. Based upon an annual parallax shift of 7.53 milliarcseconds, the distance to this star is about 430 light-years.

104 Aquarii (abbreviated 104 Aqr) is a star in the equatorial constellation of Aquarius. 104 Aquarii is the Flamsteed designation, although it also bears the Bayer designation A2 Aquarii. Based on an annual parallax shift of only 3.89 ± 0.25 milliarcseconds, the distance to this star is about 840 light-years (260 parsecs). At that range, the brightness of the star in the V-band is reduced by 0.10 magnitudes as a result of extinction caused by intervening gas and dust.

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.

<span class="mw-page-title-main">1 Aquarii</span> Binary star in the constellation Aquarius

1 Aquarii is a binary star system in the zodiac constellation of Aquarius, about 263 light years away from the Sun. 1 Aquarii is the Flamsteed designation. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 5.151, located a degree north of the celestial equator. The system is moving closer to the Earth with a heliocentric radial velocity of −41 km/s.

94 Aquarii is a triple star system in the equatorial constellation of Aquarius. 94 Aquarii is the Flamsteed designation. The brightest member has an apparent visual magnitude of 5.19, making it visible to the naked eye. The parallax measured by the Gaia spacecraft yields a distance estimate of around 73 light-years from Earth.

68 Aquarii is a single star located 270 light years away from the Sun in the zodiac constellation of Aquarius. 68 Aquarii is its Flamsteed designation, though it also bears the Bayer designation of g2 Aquarii. It is visible to the naked eye as a dim, yellow-hued star with an apparent visual magnitude of 5.24. The object is moving further from the Earth with a heliocentric radial velocity of +24.5 km/s.

41 Aquarii is a double star in the equatorial constellation of Aquarius. 41 Aquarii is its Flamsteed designation. It is visible to the naked eye as a dim, orange-hued point of light with a combined apparent visual magnitude of 5.354. The pair are located at a distance of around 239 light-years from the Sun based on parallax, but are drifting closer with a radial velocity of –25 km/s.

42 Aquarii is a single star located 447 light years away from the Sun in the zodiac constellation of Aquarius. 42 Aquarii is its Flamsteed designation. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 5.34. This object is moving further from the Sun with a heliocentric radial velocity of around +13 km/s.

<span class="mw-page-title-main">38 Aquarii</span> Star in the constellation Aquarius

38 Aquarii is a star in the equatorial constellation of Aquarius. 38 Aquarii is its Flamsteed designation; its Bayer designation is e Aquarii. It is a faint star but visible to the naked eye, with an apparent visual magnitude of +5.43. Based on parallax measurements, it is around 450 light-years away; it is 0.28 degree south of the ecliptic.

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.

30 Aquarii is a single star located about 301 light years away from the Sun in the zodiac constellation of Aquarius. 30 Aquarii is its Flamsteed designation. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.56. The star is moving further from the Earth with a heliocentric radial velocity of 40 km/s.

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.

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.

60 Aquarii is a star located 375 light years away from the Sun in the equatorial constellation of Aquarius. 60 Aquarii is its Flamsteed designation. It is visible to the naked eye as a dim, yellow-hued star with an apparent visual magnitude of 5.89. The star is moving closer to the Earth with a heliocentric radial velocity of –8 km/s.

17 Aquarii, abbreviated 17 Aqr, is a spectroscopic binary 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. The distance to 17 Aqr can be estimated from its annual parallax shift of 4.9 mas, which yields a separation of around 660 light years. It is moving further away with a heliocentric radial velocity of 18 km/s.

82 Aquarii is a star in the equatorial constellation of Aquarius. 82 Aquarii is its Flamsteed designation. It has an apparent visual magnitude of 6.15, which, according to the Bortle Dark-Sky Scale, means it is a faint star that requires dark rural skies to view. The annual parallax shift of 82 Aquarii is 3.6764±0.1715 mas, which equates to a distance of roughly 890 light-years from Earth. Because this star is positioned near the ecliptic, it is subject to lunar eclipses.

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.

56 Sagittarii is a single star in the southern constellation of Sagittarius. It has the Bayer designation f Sagittarii, while 56 Sagittarii is the Flamsteed designation. This object is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4.87. It is located approximately 208 light years away from the Sun based on parallax, and is drifting further away with a radial velocity of +22 km/s.

References

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