![]() "On the night of July 16–17, 1850, Whipple and Bond made the first daguerreotype of a star (Vega)"Īstrophotography, the photography of celestial objects, began in 1840 when John William Draper took an image of the Moon using the daguerreotype process. The Summer Triangle is recognizable in the northern skies for there are few other bright stars in its vicinity. This formation is the approximate shape of a right triangle, with Vega located at its right angle. This star lies at a vertex of a widely spaced asterism called the Summer Triangle, which consists of Vega plus the two first-magnitude stars Altair, in Aquila, and Deneb in Cygnus. In 210,000 years, Vega will become the brightest star in the night sky, and will peak in brightness in 290,000 years with an apparent magnitude of –0.81. ![]() Vega is the brightest of the successive northern pole stars. Through precession, the pole will again pass near Vega around 14,000 CE. At present the pole star is Polaris, but around 12,000 BCE the pole was pointed only five degrees away from Vega. A complete precession cycle requires 25,770 years, during which time the pole of the Earth's rotation follows a circular path across the celestial sphere that passes near several prominent stars. The direction of the Earth's axis of rotation gradually changes over time in a process known as the precession of the equinoxes. However, when a star is located along the Earth's axis of rotation, it will remain in the same position and thus is called a pole star. Vega is the bright star near the bottomĮach night the positions of the stars appear to change as the Earth rotates. The path of the north celestial pole among the stars due to the precession. In 2021, a candidate ultra-hot Neptune on a 2.43-day orbit around Vega was discovered with the radial velocity method, additionally, another possible Saturn-mass signal with a period of about 200 days. Stars that display an infrared excess due to dust emission are termed Vega-like stars. This dust is likely to be the result of collisions between objects in an orbiting debris disk, which is analogous to the Kuiper belt in the Solar System. īased on an observed excess emission of infrared radiation, Vega appears to have a circumstellar disk of dust. ![]() From Earth, Vega is observed from the direction of one of these poles. This causes the equator to bulge outward due to centrifugal effects, and, as a result, there is a variation of temperature across the star's photosphere that reaches a maximum at the poles. It is rotating rapidly with a velocity of 236 km/s at the equator. Vega is also a variable star that varies slightly in brightness. Compared with the Sun, Vega has a lower abundance of elements heavier than helium. Vega is only about a tenth of the age of the Sun, but since it is 2.1 times as massive, its expected lifetime is also one tenth of that of the Sun both stars are at present approaching the midpoint of their main sequence lifetimes. Vega has functioned as the baseline for calibrating the photometric brightness scale and was one of the stars used to define the zero point for the UBV photometric system. It was one of the first stars whose distance was estimated through parallax measurements. Vega was the first star other than the Sun to have its image and spectrum photographed. Vega was the northern pole star around 12,000 BCE and will be so again around the year 13,727, when its declination will be +86° 14′. Vega has been extensively studied by astronomers, leading it to be termed "arguably the next most important star in the sky after the Sun". It is the fifth-brightest star in the night sky, and the second-brightest star in the northern celestial hemisphere, after Arcturus. This star is relatively close at only 25 light-years (7.7 parsecs) from the Sun, and one of the most luminous stars in the Sun's neighborhood. It has the Bayer designation α Lyrae, which is Latinised to Alpha Lyrae and abbreviated Alpha Lyr or α Lyr. Vega is the brightest star in the northern constellation of Lyra.
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