Procyon

From Freepedia

This article is about the star. Procyon is also the mammalian genus to which Raccoons belong.

Procyon A/B

Observation data Epoch J2000
Constellation	Canis Minor
Right ascension	07h 39m 18.1/17.7s
Declination	+05° 13' 29/20"
Apparent magnitude (V)	0.37/10.75
Characteristics
Spectral type	F5 IV-V/DA
B-V color index	0.42
U-B color index	0.02
Variable type	None
Astrometry
Radial velocity (Rv)	-4.1 km/s
Proper motion (μ)	RA: -0.71657"/yr Dec.: -1.03458"/yr
Parallax (π)	0.28605" ± 0.00081"
Distance	11.40 ly (3.496 pc)
Absolute magnitude (MV)	2.65/13.04
Details
Mass	1.50/0.60 M☉
Radius	1.86/0.02 R☉
Luminosity	7.73/0.00055 L☉
Temperature	6,600/9,700 K
Metallicity	140%/?
Rotation period
Age	1.7 × 109 years
Visual binary orbit
Companion	Procyon B
Period (P)	40.82 years
Semimajor axis (a)	1.18"
Eccentricity (e)	0.36
Inclination (i)	31.9°
Node (Ω)	284.8°
Periastron epoch (T)	1967.86
Other designations
α Canis Minoris, 10 CMi, GCTP 1805.00 A/B, HR 2943, BD +05°1739, LHS 233, GJ 280 A/B, HIP 61421.

Image:Position Alpha Cmi.png Procyon (α CMi / α Canis Minoris / Alpha Canis Minoris) is the brightest star in the constellation Canis Minor and the eighth brightest star in the nighttime sky.

Its name comes from the Greek προκύον (Prokyōn), meaning "before the dog", since it precedes the "Dog Star" Sirius as it travels across the sky due to Earth's rotation. (Although Procyon has a greater right ascension, it also has a more northerly declination, which means it will rise above the horizon earlier than Sirius from most northerly latitudes.) These two "dog stars" are referred to in the most ancient literature and were venerated by the Babylonians and the Egyptians.

Procyon is a vertex of the Winter Triangle.

Procyon is one of the closest stars to Earth's solar system, being only 3.5 pc or 11.41 light years away. Like Sirius, it is a binary star —the main star (Procyon A) having a faint white dwarf companion (Procyon B). Its closest neighbour is Luyten's star, 0.34 pc or 1.11 ly away.

Contents 1 Procyon A 2 Procyon B 3 Astrology 4 Procyon in fiction 5 See also 6 External links

Procyon A

Procyon A is 7 times brighter than the Sun. It is considered a subgiant, meaning it has just finished fusing its hydrogen into helium and begun to expand. It is expected that the Sun will also go through this process when it begins to die.

In late June of 2004, Canada's orbital MOST satellite telescope completed a 32-day survey of Procyon A. The continuous optical monitoring was intended to confirm oscillations in its brightness observed from Earth. During the entire two month period however, no fluctuation in intensity whatever was observed. These findings have caused astrophysicists to question the accepted tenets of helioseismology, and theories of star formation.

Procyon B

Procyon B is a faint white dwarf star, with an average separation from Procyon A of about 16 times the Earth's distance from the Sun or roughly the distance between Uranus and the Sun.

Astrology

Astrologically, Procyon portends wealth, fame, and good fortune. Medieval astrologers considered it one of fifteen Behenian stars, associated with agate and water crowfoot. According to Cornelius Agrippa, its kabbalistic symbol is Image:Agrippa1531 Canisminor.png.

Procyon in fiction

• In Star Trek: Enterprise, Procyon was the scene of a formidable Federation victory during a war against an alien species known as the Sphere Builders. The USS Enterprise-J took part in this battle. In 2153, Captain Jonathan Archer was brought 400 years forward in time to witness part of the battle.

• The human colony world of We Made It (which is mentioned in Larry Niven's stories and books of the Known Space) orbits Procyon. Pierson's Puppeteers are said to have evolved in a solar system with a star similar to Procyon (which later became a red giant).

• In Star Trek, Procyon is said to be the primary star system for Andoria. The homeworld of the Andorians is the moon of a gas giant orbiting Procyon.

See also

• List of nearest stars

External links

• Sol Station — Procyon