The Radial Velocity, that is the speed at which the star is moving away/towards the Sun is -2.70000 km/s with an error of about 1.01 km/s . This Hexagon or Winter Circle – is formed by Procyon, Sirius, Pollux, Capella, Auriga, Aldebaran, and Rigel – some of them being in different constellations. He compared his astrometric measurements to those given in Ptolemy’s Almagest – 2nd Century C.E – and thus concluded that the stars were not in fact “fixed.”. Procyon, an aw designatit Alpha Canis Minoris (α Canis Minoris, abbreviatit Alpha CMi, α CMi), is the brichtest starn in the constellation o Canis Minor. Procyon estimated radius has been calculated as being 2.09 times bigger than the Sun. [citation needed]. Were the Sun to be observed from this star system, it would appear to be a magnitude 2.55 star in the constellation Aquila with the exact opposite coordinates at right ascension 19h 39m 18.11950s, declination −05° 13′ 29.9552″. The name Procyon comes from the Ancient Greek Προκύων (Prokyon), meaning "before the dog", since it precedes the "Dog Star" Sirius as it travels across the sky due to Earth's rotation. avalaunch33 Vapoteur diplomé Messages : 11691 Enregistré le : sam. However, it is actually a binary star system, consisting of a white main sequence star (spectral type F5 IV-V) named Procyon A, and a faint white dwarf companion (spectral type DA) named Procyon B. Procyon is bright not because of its intrinsic luminosity but because of its close proximity to the Sun; at a distance of 11.46 light years (3.51 parsecs), it is one of our near neighbours. Proper Motion details the movements of these stars and are measured in milliarcseconds. The image above shows the uncropped view of Procyon (North is up) through the Takahashi E-180 Astrograph. It has a mass of 1.4 solar masses and a diameter 2 times the Sun. Like Sirius B, Procyon's companion is a white dwarf that was inferred from astrometric data long before it was observed. [18], The primary has a stellar classification of F5IV–V, indicating that it is a late-stage F-type main-sequence star. Its low mass is unusual for a white dwarf for reasons that are yet unclear. The description above is based on the Procyon entry in Wikipedia. Procyon A is bright for its spectral class, suggesting that it is a subgiant that has nearly fused its core hydrogen into helium. window.twttr = (function(d, s, id) { To the ancient Egyptians, Procyon represented Nangar, an aspect of the god Marduk known as the Carpenter. Its existence had been postulated by German astronomer Friedrich Bessel as early as 1844, and, although its orbital elements had been calculated by his countryman Arthur Auwers in 1862 as part of his thesis,[28] Procyon B was not visually confirmed until 1896 when John Martin Schaeberle observed it at the predicted position using the 36-inch refractor at Lick Observatory. The continuous optical monitoring was intended to confirm solar-like oscillations in its brightness observed from Earth and to permit asteroseismology.