Tuesday nights warmup or camera cooldown.

Vega or Alpha Lyrae is the brightest star in the constellation Lyra, and the fifth brightest star in the sky. It is a bluish-white star with a magnitude of 0.03. Vega is sometimes called the Harp star since Lyra represents the Harp of Orpheus in Greek mythology. Vega is also the brightest of the three stars in the Summer Triangle (along with Deneb and Altair). Vega and Arcturus dominate the northern summer sky.Vega is a blue-white class A0 V main sequence star only 25.3 light years away, making it one of the closer stars to Earth. Being nearby, Vega has a relatively high proper motion of 0.328"/yr, which results in angular movement of a degree every 11,000 years. Its radial velocity is 13.9 km/s towards the Sun. Vega will become the brightest star in the sky in around 210,000 years, will attain a peak brightness of magnitude 0.81 in about 290,000 years, and will be the brightest star in the sky for about 270,000 years. Based on its space motion, Vega appears to belong to a stellar association called the Castor Moving Group, which contains about 16 stars (including Castor and Fomalhaut as well as Vega). These stars' group membership implies a common origin in an open cluster that has since become gravitationally unbound.Vega has an unusually low abundance of "metals", i.e. elements heavier then helium, making it a weak Lambda Bootis star. It is also a suspected variable star of the Delta Scuti variety, pulsating with an amplitude of 0.03 magnitudes over a period of 0.107 days, but this has not been confirmed.Vega rotates rapidly, with a velocity of 274 km/s at the equator, for a rotation period of about 12.5 hours. This is 93% of the speed that would cause the star to break up from centrifugal effects, and it causes Vega's equator to bulge outward by 23% compared to its polar radius. From the Earth, we view this bulge from within five degrees of Vega's polar axis. This produces the unexpectedly large radius observed by interferometric measurements of Vega's apparent disk - 2.78 solar radii at the equator, but only 2.26 at the poles.Centrifugal effects also cause a temperature variation across Vega's photosphere, from 7600 K at the equator to 10,000 K near the poles. Calculation of Vega's luminosity is therefore much more difficult than for a slowly rotating star. In Vega's case, it comes out to about 37 times the Sun's, which gives a mass of 2.3 suns, and an age of about 400 million years. Vega is a relatively young star, fusing hydrogen to helium in its core. Since massive stars fuse their hydrogen fuel more quickly than smaller ones, Vega's main sequence lifetime is only one billion years - a tenth of our Sun's. After leaving the main sequence, Vega will become a class M red giant, then shed much of its mass, finally becoming a white dwarf. Vega has two faint companions that are not physically related, but merely lie along the same line of sight.Dust Disk and PlanetsExcessive infrared emissions from Vega, first detected by the Infrared Astronomical Satellite (IRAS) in 1983, indicated the presence of dusty disk of particulate matter orbiting the star at a distance of 80 - 120 AU. Vega was the first star to have such a dust disk detected around it, but since then more than 400 others have been discovered. The dust disk was first thought to be protoplanetary material, in the process of collapsing to form a planet. But it is now more likely to be debris, produced by collisions in an outer asteroid population corresponding to the Kuiper Belt around our Sun. Observations in 2006 revealed evidence for an inner dust band around Vega, within 8 AU of the star, that may be caused by an intense bombardment of comets and meteors, and may be evidence of an inner planetary system. Although no planets have been directly observed around Vega, the presence of a planetary system cannot yet be precluded. Clumps observed in the dust disk may be caused by a Jupiter-mass planet in an eccentric orbit, or by a Neptune-mass planet having migrated from 40 to 65 AU. Observations in 2005 constrained the size of a planet orbiting Vega to no more than 5 to 10 times the mass of Jupiter. Alternately, the lumps may indicate a planet still undergoing formation. Determining their nature has not been straightforward.With the discovery of its dust disk as inspiration, Vega played the role of home to an alien civilization in the 1997 science fiction movie, "Contact". 
@information from Sky Safari Pro version 7.