Pi Ceti

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Pi Ceti
Eridanus constellation map.svg
Red circle.svg
Location of Pi Ceti (circled)
Observation data
Epoch J2000.0        Equinox J2000.0 (ICRS)
Constellation Cetus
Right ascension 02h 44m 07.34928s [1]
Declination −13° 51′ 31.3130″ [1]
Apparent magnitude  (V)4.238 [2]
Characteristics
Spectral type B7 V [3] or B7 IV [4]
U−B color index −0.396 [2]
B−V color index −0.130 [2]
Astrometry
Proper motion (μ)RA: −8.62 [1]   mas/yr
Dec.: −9.07 [1]   mas/yr
Parallax (π)8.30 ± 0.21  mas [1]
Distance 393 ± 10  ly
(120 ± 3  pc)
Absolute magnitude  (MV)−1.16 [5]
Orbit [6]
Period (P)2,722±14 d
Eccentricity (e)0.0±0.7
Periastron epoch (T)2444852 ± 29 JD
Argument of periastron (ω)
(secondary)		0.0°
Semi-amplitude (K1)
(primary)		4.33±0.25 km/s
Details [7]
π Cet A
Mass 4.4±0.2  M☉
Radius 4.3±0.3  R☉
Luminosity 468  L☉
Surface gravity (log g)3.8±0.2  cgs
Temperature 12,900±400  K
Metallicity [Fe/H]0.28±0.16 [8]   dex
Rotational velocity (v sin i)20.9±1.2 km/s
Age 0.3+0.1
−0.1  Myr
Other designations
π Cet, 89 Ceti, BD−14 519, FK5 97, HD  17081, HIP  12770, HR  811, SAO  148575. [9]
Database references
SIMBAD data

Pi Ceti, Latinized from π Ceti, is the Bayer designation for a star system in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of 4.238. [2] Observed to have an Earth half yearly parallax shift of 8.30  mas, [1] it is around 393  light years from the Sun.

This is a single-lined spectroscopic binary system with a nearly circular orbit and a period of 7.45 years. The fact that the system has a negligible eccentricity is surprising for such a long period, and may suggest that the secondary is a white dwarf that had its orbit circularized during a mass-transfer event. [6]

The primary, component A, is a normal B-type star [7] that has been given stellar classifications of B7 V [3] and B7 IV. [4] It appears very young – less than half a million years in age – and may still be on a pre-main sequence track. The star shows no magnetic field but it does emit an infrared excess. [7]

Name

This star, along with ε Cet, ρ Cet and σ Cet, was Al Sufi's Al Sadr al Ḳaiṭos, the Whale's breast/chest (upper torso). [10] Per Jack Rhoads's Reduced Star Catalog Containing 537 Named Stars, Al Sufi's numerically ordered stars (1 to 4), were ρ (rho), σ (sigma), ε (epsilon) and this star. [11]

In Chinese, 天苑 (Tiān Yuàn), meaning Celestial Meadows , refers to an asterism consisting of π Ceti, and 15 stars in Eridanus: γ, π, δ, ε, ζ, η, and the string of τ (Tau)1, 2, 3, 4, 5, 6, 7, 8 and 9. Consequently, the Chinese name for the star is 天苑七 (Tiān Yuàn qī) meaning Celestial Meadows: seven. [12]

Related Research Articles

<span class="mw-page-title-main">Alpha Ceti</span> Star in the constellation Cetus

Alpha Ceti, officially named Menkar, is the second-brightest star in the constellation of Cetus. It is a cool luminous red giant estimated to be about 250 light years away based on parallax.

<span class="mw-page-title-main">Pi Virginis</span> Binary star in the constellation Virgo

Pi Virginis is a binary star in the zodiac constellation of Virgo. It is visible to the naked eye with an apparent visual magnitude of 4.64. The distance to this star, based upon parallax measurements, is roughly 380 light years.

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

Pi Andromedae is the Bayer designation for a binary star system in the northern constellation of Andromeda. With an apparent visual magnitude of 4.4, it is visible to the naked eye. It is located approximately 580 light-years from Earth.

<span class="mw-page-title-main">Pi Arietis</span> Multiple star system in the constellation Aries

Pi Arietis, Latinized from π Arietis, is the Bayer designation for a multiple star system in the northern constellation of Aries. Based upon parallax measurements made during the Hipparcos mission, this system is approximately 800 light-years distant from Earth and has an apparent visual magnitude of 5.21. This is bright enough to be faintly seen with the naked eye.

<span class="mw-page-title-main">Zeta Ceti</span> Binary star in the constellation Cetus

Zeta Ceti is a binary star in the equatorial constellation of Cetus. It has a combined apparent visual magnitude of 3.74, which is bright enough to be seen with the naked eye. Based upon parallax measurements taken during the Hipparcos mission, it is approximately 235 light-years from the Sun.

Pi1 Cygni (π1 Cygni, abbreviated Pi1 Cyg, π1 Cyg) is a binary star in the northern constellation of Cygnus. It is visible to the naked eye, having a combined apparent visual magnitude of 4.66. The distance to this system can be roughly gauged by its annual parallax shift of 1.89 mas, which yields a separation of around 1,700 light years from the Sun, give or take a hundred light years.

<span class="mw-page-title-main">Eta Ceti</span> Star in the constellation Cetus

Eta Ceti is a star in the equatorial constellation of Cetus. It has the traditional name Deneb Algenubi or Algenudi. The apparent visual magnitude of this star is +3.4, making it the fourth-brightest star in this otherwise relatively faint constellation. The distance to this star can be measured directly using the parallax technique, yielding a value of 123.9 light-years.

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

Delta Ceti, Latinized from δ Ceti, is a single, blue-white hued star in the equatorial constellation of Cetus. The star's apparent visual magnitude of +4.06 means it is near to the cusp of the faintest third of the stars that are visible the ideally-placed naked eye. It is 0.3238° north of the celestial equator compared to the celestial north pole's 90°. The star is positioned about 0.74° WNW of the spiral galaxy M77, but which at apparent magnitude 9.6 needs magnification to be made out and has an apparent size of only 0.1° by 0.12°.

Theta Ceti, Latinized from θ Ceti, is a solitary, orange-hued star in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of 3.60. Based upon an annual parallax shift of 28.66 mas as seen from Earth, it is located about 114 light-years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.10 due to interstellar dust.

Pi2 Cygni, Latinized from π2 Cygni, is a triple star system in the northern constellation of Cygnus. It is visible to the naked eye about 2.5° east-northeast of the open cluster M39, having an apparent visual magnitude of 4.24. Based upon an annual parallax shift of 2.95 mas, it is located at a distance of roughly 1,100 light years from the Sun.

<span class="mw-page-title-main">Epsilon Herculis</span> Multiple star systen in the constellation Hercules

Epsilon Herculis, Latinized from ε Herculis, is a fourth-magnitude multiple star system in the northern constellation of Hercules. The combined apparent visual magnitude of 3.9111 is bright enough to make this system visible to the naked eye. Based upon an annual parallax shift of 21.04 mas as seen from Earth, it is located 155 light years from the Sun. The system is moving closer to the Sun with a radial velocity of −25 km/s.

<span class="mw-page-title-main">Lambda Ceti</span> Star in the constellation Cetus

Lambda Ceti, Latinized from λ Ceti, is B-type star of fifth-magnitude located in the constellation Cetus. Historically, the star bore the traditional name Menkar, although today that name is more commonly associated with α Ceti.

<span class="mw-page-title-main">Xi Piscium</span> Binary star system in the constellation Pisces

Xi Piscium (ξ Piscium) is an orange-hued binary star system in the zodiac constellation of Pisces. In 1690, the astronomer Johannes Hevelius in his Firmamentum Sobiescianum regarded the constellation Pisces as being composed of four subdivisions. Xi Piscium was considered to be part of the Linum Austrinum, the South Cord. The star is visible to the naked eye, having an apparent visual magnitude of 4.60. Based upon an annual parallax shift of 11.67 mas as seen from Earth, it is located about 280 light years from the Sun. It is moving away from the Sun, having a radial velocity of +26 km/s.

Epsilon Ceti, Latinized from ε Ceti, is the Bayer designation for a binary star system located in the equatorial constellation of Cetus. It is faintly visible to the naked eye with an apparent visual magnitude of +4.84. Based upon an annual parallax shift of 14.58 mas, it is located around 98 light-years away from the Sun.

<span class="mw-page-title-main">Nu Ceti</span> Binary star system in the constellation Cetus

ν Ceti, Latinized as Nu Ceti, is a binary star system in the equatorial constellation of Cetus. It is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of 4.86. The system is located approximately 340 light years distant from the Sun, based on parallax, and is drifting further away with a radial velocity of 4.8 km/s. Nu Ceti is believed to be part of the Ursa Major stream of co-moving stars.

Xi<sup>1</sup> Ceti Star in the constellation Cetus

Xi1 Ceti , Latinized from ξ1 Ceti, is a binary star system located in the equatorial constellation of Cetus. It is visible to the naked eye with a combined apparent visual magnitude of +4.36. The distance to this system is approximately 340 light years based on parallax measurements, and it is drifting closer to the Sun with a radial velocity of −4 km/s. The proximity of the star to the ecliptic means it is subject to lunar occultations.

Rho Ceti , Latinized from ρ Ceti, is the Bayer designation for a star in the equatorial constellation of Cetus. It is faintly visible to the naked eye with an apparent visual magnitude of 4.885. The distance to this star, based upon an annual parallax shift of 7.15 mas, is around 460 light years.

Sigma Ceti is the Bayer designation for a star in the equatorial constellation of Cetus. With an apparent visual magnitude of 4.78, it can be seen with the naked eye on a dark night. Based upon an annual parallax shift of 37.46 mas, it lies at an estimated distance of 87.1 light years from the Sun. It is a probable astrometric binary star system.

<span class="mw-page-title-main">Eta Hydrae</span> Star in the constellation Hydra

Eta Hydrae is a star in the equatorial constellation of Hydra. With an apparent visual magnitude of 4.3, it is visible to the naked eye. However, it is the faintest of the five stars that form the "head" of the hydra. Based upon an annual parallax shift of 5.56 mas, it is located roughly 590 light years from the Sun.

Pi<sup>5</sup> Orionis Spectroscopic binary star system in the constellation Orion

Pi5 Orionis (π5 Ori, π5 Orionis) is a binary star system in the constellation Orion. It has an apparent visual magnitude of 3.69, which is bright enough to be visible to the naked eye on a clear night. Based upon an annual parallax shift of 2.43 mas, it is around 1,300 light-years distant from the Sun.

References

  1. 1 2 3 4 5 6 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv: 0708.1752 , Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID   18759600.
  2. 1 2 3 4 Gutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile, Publicaciones Universidad de Chile, Department de Astronomy, 1: 1–17, Bibcode:1966PDAUC...1....1G.
  3. 1 2 Buscombe, W. (1962), "Spectral classification of Southern fundamental stars", Mount Stromlo Observatory Mimeogram, 4: 1, Bibcode:1962MtSOM...4....1B.
  4. 1 2 Hohle, M. M.; et al. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten, 331 (4): 349, arXiv: 1003.2335 , Bibcode:2010AN....331..349H, doi:10.1002/asna.200911355, S2CID   111387483.
  5. ↑ 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.
  6. 1 2 Lacy, C. H. S.; et al. (March 1997), "The Spectroscopic Orbit of Pi Ceti", Astronomical Journal, 113: 1088, Bibcode:1997AJ....113.1088L, doi: 10.1086/118325 .
  7. 1 2 3 Folsom, C. P.; et al. (May 2012), "Chemical abundances of magnetic and non-magnetic Herbig Ae/Be stars", Monthly Notices of the Royal Astronomical Society, 422 (3): 2072–2101, arXiv: 1202.1845 , Bibcode:2012MNRAS.422.2072F, doi:10.1111/j.1365-2966.2012.20718.x, S2CID   119100447.
  8. ↑ Prugniel, Ph.; Vauglin, I.; Koleva, M. (July 2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics, 531: A165, arXiv: 1104.4952 , Bibcode:2011A&A...531A.165P, doi:10.1051/0004-6361/201116769, S2CID   54940439.
  9. ↑ "pi. Cet -- Spectroscopic binary", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-02-08.
  10. ↑ Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York: Dover Publications Inc. p.  162. ISBN   0-486-21079-0 . Retrieved 2010-12-12.
  11. ↑ Jack W. Rhoads - Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars, Jet Propulsion Laboratory, California Institute of Technology; November 15, 1971
  12. ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 12 日
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