Psi Capricorni

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Star
ψ Capricorni
ψ Cap in the constellation "Capricorn"
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation Capricorn
Right ascension 20 h 46 m 5.73 s
declination -25 ° 16 ′ 15.2 ″
Apparent brightness 4.23 mag
Typing
B − V color index 0.39 
Spectral class F5 V
Astrometry
Radial velocity (25.6 ± 0.7) km / s
parallax (68.13 ± 0.27)  mas
distance (47.9 ± 0.2)  ly
(14.68 ± 0.06)  pc
Proper movement 
Rec. Share: (−51.96 ± 0.25)  mas / a
Dec. portion: (−156.56 ± 0.22)  mas / a
Physical Properties
Effective temperature 6630  K
Metallicity [Fe / H] −0.08
Other names
and catalog entries
Bayer name ψ Capricorni
Flamsteed name 16 capricorni
Cordoba Survey CD −25 ° 15018
Bright Star Catalog HR 7936 [1]
Henry Draper Catalog HD 197692 [2]
Gliese catalog GJ 805 [3]
Hipparcos catalog HIP 102485 [4]
SAO catalog SAO 189664 [5]
Tycho catalog TYC 6925-1576-1 [6]Template: Infobox star / maintenance / specification of the TYC catalog
2MASS catalog 2MASS 20460572-2516153 [7]
Other names FK5 779

Psi Capricorni (ψ Cap) is a star in the constellation Capricorn . It has an apparent magnitude of 4.2 mag and its distance is approximately 48 light years .

The star is a white and yellow main sequence star with about 1.4 times the diameter, 1.3 times the mass and 4 times the luminosity of the sun . The star is therefore only slightly larger than our sun and its surface temperature of about 6630 K is also only about 850 K higher than that of the sun. However, the star rotates with a projected equatorial rotation speed v ∙ sin i of about 41 km / s at least 20 times faster than the sun and, with an estimated age of about 1–2 billion years, is also significantly younger than the sun.

Psi Capricorni is occasionally referred to as "Pazan" (from Persian پازن, DMG pāzen , 'Capricorn').

Scientific research

For Psi Capricorni succeeded in 2000 at the La Silla Observatory of ESO for the first time (of the sun), the differential rotation to determine a star's surface. The equatorial zone rotates about 15% faster than the higher latitudes, this value is comparable to the value of 20% for the sun.

Because of the relatively large similarity of Psi Capricorni our sun and its close proximity to the star was a qualified candidate for the search for Earth-like planets in the project Terrestrial Planet Finder of NASA .

Individual evidence

  1. ^ A b c d VizieR: Hipparcos, the New Reduction (van Leeuwen, 2007) - The Astrometric Catalog
  2. ↑ a b c d VizieR: NStars project: The southern sample. I. (Gray +, 2006)
  3. ↑ VizieR: Pulkovo radial velocities for 35493 HIP stars (Gontcharov, 2006)
  4. ^ VizieR. Fundamental parameters of stars (Allende Prieto +, 1999)
  5. ^ VizieR: Rotation in AF stars (Ammler-von Eiff +, 2012)
  6. ↑ VizieR: Atmospheric parameters for nearby BF stars (David +, 2015)
  7. ^ P. Moore, R. Rees: Patrick Moore's Data Book of Astronomy . Cambridge University Press, Cambridge 2011, ISBN 978-0-521-89935-2 , p. 397.
  8. ↑ A. Reiners, JHMM Schmitt, M. Kürster: Detection of differential rotation in ψ Cap with profile analysis. In: Astronomy & Astrophysics. Vol. 376, 2001, doi: 10.1051 / 0004-6361: 20011023 , pp. L13-L16 ( PDF; 185 KB ).
  9. ^ RA Brown, SL Hunyadi, SB Shaklan: A Design Reference Mission for the Coronagraphic Terrestrial Planet Finder. 2006 ( PDF; 3.92 MB ).