VEGA BECOMES THE FIRST STAR TO BE PHOTOGRAPHED

Today, The Grandma has received the wonderful visit of Joseph de Ca'th Lon, one of her closest friends. 

Joseph loves Astronomy and thay have been talking about Vega, the first star, other than the Sun, to be photographed on a day like today in 1850.

Vega is the brightest star in the northern constellation of Lyra. It has the Bayer designation α Lyrae, which is Latinised to Alpha Lyrae and abbreviated Alpha Lyr or α Lyr. 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 is the fifth-brightest star in the night sky, and the second-brightest star in the northern celestial hemisphere, after Arcturus.

Vega has been extensively studied by astronomers, leading it to be termed arguably the next most important star in the sky after the Sun.

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 was the first star other than the Sun to have its image and spectrum photographed. It was one of the first stars whose distance was estimated through parallax measurements. 

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.

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. Compared with the Sun, Vega has a lower abundance of elements heavier than helium.

Vega is also a variable star -that is, a star whose brightness fluctuates. It is rotating rapidly with a speed of 236 km/s at the equator. 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. From Earth, Vega is observed from the direction of one of these poles.

Based on observations of more infrared radiation than expected, Vega appears to have a circumstellar disk of dust. 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. Stars that display an infrared excess due to dust emission are termed Vega-like stars.

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.

α Lyrae (Latinised to Alpha Lyrae) is the star's Bayer designation. The traditional name Vega (earlier Wega) comes from a loose transliteration of the Arabic word wāqi', in Arabic واقع, meaning falling or landing, via the phrase an-nasr al-wāqi', in Arabic النّسر الْواقع, the falling eagle.

In 2016, the International Astronomical Union (IAU) organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included Vega for this star. It is now so entered in the IAU Catalog of Star Names.

Vega can often be seen near the zenith in the mid-northern latitudes during the evening in the Northern Hemisphere summer. From mid-southern latitudes, it can be seen low above the northern horizon during the Southern Hemisphere winter.

Astrophotography, the photography of celestial objects, began in 1840 when John William Draper took an image of the Moon using the daguerreotype process.

On 17 July 1850, Vega became the first star (other than the Sun) to be photographed, when it was imaged by William Bond and John Adams Whipple at the Harvard College Observatory, also with a daguerreotype.

In August 1872, Henry Draper took a photograph of Vega's spectrum, the first photograph of a star's spectrum showing absorption lines. Similar lines had already been identified in the spectrum of the Sun.

In 1879, William Huggins used photographs of the spectra of Vega and similar stars to identify a set of twelve very strong lines that were common to this stellar category. These were later identified as lines from the Hydrogen Balmer series.

Vega has a rotation period of 16.3 hours, much faster than the Sun's rotational period but similar to, and slightly slower than, those of Jupiter and Saturn. Because of that, Vega is significantly oblate like those two planets. y which other stars are classified.

More information: Space

 Aim for the moon. If you miss, you may hit a star.

W. Clement Stone.