7 Cephei

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7 Cephei
Observation data
Epoch J2000       Equinox J2000
Constellation Cepheus
Right ascension 21h 27m 46.14144s [1]
Declination +66° 48 32.7406 [1]
Apparent magnitude  (V)5.42 [2]
Characteristics
Evolutionary stage main sequence [3]
Spectral type B7 V [4]
B−V color index −0.099±0.004 [2]
Astrometry
Radial velocity (Rv)+3.0±4.2 [5]  km/s
Proper motion (μ)RA: −11.296 [1]   mas/yr
Dec.: −19.787 [1]   mas/yr
Parallax (π)3.9653 ± 0.1148  mas [1]
Distance 820 ± 20  ly
(252 ± 7  pc)
Absolute magnitude  (MV)−1.54 [2]
Details
Mass 4.47±0.07 [3]   M
Radius 3.0 [6]   R
Luminosity 769+94
−84
[3]   L
Surface gravity (log g)3.56 [7]   cgs
Temperature 12,560+87
−86
[3]   K
Metallicity [Fe/H]−0.36 [7]   dex
Rotational velocity (v sin i)236 [3]  km/s
Age 38 [8]   Myr
Other designations
7 Cep, BD+66°1405, FK5  3718, HD  204770, HIP  105972, HR  8227, SAO  19432 [9]
Database references
SIMBAD data

7 Cephei is a single [10] star located approximately 820  light years away, in the northern circumpolar constellation of Cepheus. It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude of 5.42. [2]

This is a B-type main-sequence star with a stellar classification of B7 V. [4] It is a candidate variable star with an amplitude of 9  micromagnitudes and a period of 0.737±0.002 d. [11] This object has 4.5 [3] times the mass of the Sun and about three [6] times the Sun's radius. It is spinning rapidly with a projected rotational velocity of 236 km/s. [3] 7 Cephei is radiating 769 [3] times the luminosity of the Sun from its photosphere at an effective temperature of 12,560 K. [3]

Related Research Articles

10 Boötis is a suspected astrometric binary star system in the northern constellation of Boötes, located around 528 light years away from the Sun. It is visible to the naked eye under suitable viewing conditions as a dim, white-hued star with an apparent visual magnitude of 5.76. Its magnitude is diminished by an extinction of 0.17 due to interstellar dust. This system is moving away from the Earth with a heliocentric radial velocity of +6 km/s.

5 Cancri is a single star in the zodiac constellation of Cancer, located around 520 light years away from the Sun. It is just visible to the naked eye under good seeing conditions as a dim, blue-white hued star with an apparent visual magnitude of 5.99. This object is moving closer to the Sun with a heliocentric radial velocity of −10 km/s.

66 Cancri is a binary star system near the northern border of the zodiac constellation of Cancer, located 474 light years away from the Sun. It is visible to the naked eye as a faint, white-hued star with a combined apparent visual magnitude of 5.87. The pair are moving closer to the Earth with a heliocentric radial velocity of −13 light years. As of 2003, the magnitude 8.56 companion was located at an angular separation of 4.43″ along a position angle of 134° from the primary.

Rho2 Cephei, Latinized from ρ2 Cephei, or simply ρ Cephei, is a solitary star in the northern constellation of Cepheus. With an apparent visual magnitude of 5.50, it is faintly visible to the naked eye, forming an optical pair with Rho1 Cephei. Based upon an annual parallax shift of 13.31 mas as seen from the Earth, it is located about 245 light years from the Sun.

42 Camelopardalis is a single star in the constellation Camelopardalis, located roughly 770 light years away from the Sun. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 5.14. The visual magnitude of the star is diminished by an extinction of 0.22 due to interstellar dust. It is moving further from the Earth with a heliocentric radial velocity of 3 km/s. 42 Camelopardalis has a peculiar velocity of 24.4+1.9
−2.1
 km/s
and may be a runaway star.

HD 69863 is a binary star system in the southern constellation of Carina. It is visible to the naked eye as a dim point of light with a combined apparent visual magnitude of 5.16. The system is located at a distance of about255 light years from the Sun based on parallax. The dual nature of this system was announced in 1832 by German astronomer Carl Rümker. As of 2015, the pair had an angular separation of 4.10″ along a position angle of 70°.

<span class="mw-page-title-main">Iota Lyrae</span> Binary star in the constellation Lyra

ι Lyrae, Latinised as Iota Lyrae, is a binary star in the northern constellation of Lyra. It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude that fluctuates around 5.22. This object is located approximately 910 light years distant from the Sun based on parallax, but is drifting nearer with a radial velocity of −26 km/s.

<span class="mw-page-title-main">HD 204521</span> Star in the constellation Cepheus

HD 204521 is a star in the northern constellation of Cepheus. In the sky it positioned just to the west of the magnitude 3.2 star Beta Cephei. This object has a yellow hue similar to the Sun but is too faint to be visible to the naked eye with an apparent visual magnitude of 7.26. It is located at a distance of 86 light years from the Sun based on parallax, and has an absolute magnitude of 5.15. The star is drifting closer with a radial velocity of −77 km/s, and is predicted to come to within 7.96 light-years in 334,000 years. At that distance the star can have a relatively small perturbing effect on comets in the Oort cloud.

Omega<sup>1</sup> Cygni B-type subgiant star in the constellation Cygnus

Omega1 Cygni, Latinized from ω1 Cygni, is the Bayer designation for a solitary star in the northern constellation of Cygnus. It is visible to the naked eye with an apparent visual magnitude of 4.94. Based upon an annual parallax shift of 2.59 mas, it is estimated to lie roughly 1,260 light years from the Sun. Relative to its neighbors, this star has a peculiar velocity of 25.7±2.2 km/s.

HD 125442 is a single star in the southern constellation of Lupus. Its apparent visual magnitude is 4.78, which can be seen with the naked eye. The distance to HD 125442, as determined from its annual parallax shift of 22.1 mas, is 147 light years.

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

ν Pegasi, Latinized as Nu Pegasi is a single star in the northern constellation of Pegasus. It is an orange-hued star that is faintly visible to the naked eye with an apparent visual magnitude of 4.84. The star is located approximately 261 light years away based on parallax, but is drifting closer with a radial velocity of −19 km/s.

<span class="mw-page-title-main">ET Virginis</span> Evolved red giant star in the constellation Virgo

ET Virginis is a single, red-hued star in the equatorial constellation of Virgo. It can be viewed with the naked eye, having an apparent visual magnitude of 4.91. Based upon an annual parallax shift of 5.9 mas, it is located 560 light years away. It is moving further from the Earth with a heliocentric radial velocity of +18.6 km/s, having come within 177 ly of the Sun around 6.3 million years ago.

HD 83446 is a probable astrometric binary star system in the constellation Vela. It is visible to the naked eye with an apparent visual magnitude of 4.34. Based upon an annual parallax shift of 30.5 mas, it is located 107.1 light years from the Sun. The system is moving further away with a heliocentric radial velocity of +18 km/s.

<span class="mw-page-title-main">31 Persei</span> Star in the constellation Perseus

31 Persei is a single star in the northern constellation of Perseus. It is visible to the naked eye as a dim, blue-white hued point of light with an apparent visual magnitude of 5.05. This star is located around 172 parsecs (560 ly) away from the Sun, and it is drifting closer with a radial velocity of −1.6 km/s. It is likely a member of the Alpha Persei Cluster.

<span class="mw-page-title-main">HD 23753</span> Star in the constellation Taurus

HD 23753 is a single star in the equatorial zodiac constellation of Taurus, and is a member of the Pleiades open cluster. It is dimly visible to the naked eye with an apparent visual magnitude of 5.44. The distance to this star, as determined from its annual parallax shift of 7.7 mas, is about 420 light years. It is moving further from the Earth with a heliocentric radial velocity of +8 km/s. The star is positioned near the ecliptic and so is subject to lunar occultations.

<span class="mw-page-title-main">Upsilon Coronae Borealis</span> Star in the constellation Corona Borealis

Upsilon Coronae Borealis, Latinized from υ Coronae Borealis, is a solitary star in the northern constellation of Corona Borealis. It is a white-hued star that is dimly visible to the naked eye with an apparent visual magnitude of 5.78. The distance to this object is approximately 630 light-years based on parallax.

<span class="mw-page-title-main">BW Vulpeculae</span> Star in the constellation Vulpecula

BW Vulpeculae or BW Vul, is a variable star in the northern constellation of Vulpecula. It is near the lower limit of visibility to the naked eye with a typical apparent visual magnitude of 6.54. Based on an annual parallax shift of 1.15 mas, the distance to BW Vul is about 2,800 light years. It is moving closer to the Earth with a baseline heliocentric radial velocity of around −6 km/s.

Gamma<sup>2</sup> Fornacis Star in the constellation Fornax

Gamma2 Fornacis, a name Latinized from γ2 Fornacis, is a single star in the southern constellation Fornax. It has a white hue and is faintly visible to the naked eye at night with an apparent visual magnitude of 5.4. The distance to Gamma2 Fornacis is approximately 520 light years based on parallax. It is drifting further away with a radial velocity of 24 km/s. Gamma1 Fornacis is a 6th magnitude star about four degrees to the north.

HD 53501, is a solitary star in the southern circumpolar constellation Volans. It has an apparent magnitude of 5.18, allowing it to be seen with the naked eye under ideal conditions. The object is located at a distance of 308 light years but is receding with a heliocentric radial velocity of 39 km/s.

HD 46815 is a solitary star in the southern constellation Columba. It is faintly visible to the naked eye with an apparent magnitude of 5.4 and is estimated to be 408 light years away. However, it is receding with a heliocentric radial velocity of 32.2 km/s.

References

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