Coma (cometary)

The coma is the nebulous envelope around the nucleus of a comet. It is formed when the comet passes close to the Sun on its highly elliptical orbit; as the comet warms, parts of it sublimate. This gives a comet a "fuzzy" appearance when viewed in telescopes and distinguishes it from stars. The word coma comes from the Greek "kome" (κόμη), which means "hair" and is the origin of the word comet itself.

The coma is generally made of ice and comet dust. Water dominates up to 90% of the volatiles that outflow from the nucleus when the comet is within 3-4 AU of the Sun. The H₂O parent molecule is destroyed primarily through photodissociation and to a much smaller extent photoionization. The solar wind plays a minor role in the destruction of water compared to photochemistry. Larger dust particles are left along the comet's orbital path while smaller particles are pushed away from the Sun into the comet's tail by light pressure.

On 11 August 2014, astronomers released studies, using the Atacama Large Millimeter/Submillimeter Array (ALMA) for the first time, that detailed the distribution of HCN, HNC, H₂CO, and dust inside the comae of comets C/2012 F6 (Lemmon) and C/2012 S1 (ISON). On 2 June 2015, NASA reported that the ALICE spectrograph on the Rosetta space probe studying comet 67P/Churyumov–Gerasimenko determined that electrons (within 1 km (0.62 mi) above the comet nucleus) produced from photoionization of water molecules by solar radiation, and not photons from the Sun as thought earlier, are responsible for the degradation of water and carbon dioxide molecules released from the comet nucleus into its coma.

Coma (optics)

In optics (especially telescopes), the coma, or comatic aberration, in an optical system refers to aberration inherent to certain optical designs or due to imperfection in the lens or other components that results in off-axis point sources such as stars appearing distorted, appearing to have a tail (coma) like a comet. Specifically, coma is defined as a variation in magnification over the entrance pupil. In refractive or diffractive optical systems, especially those imaging a wide spectral range, coma can be a function of wavelength, in which case it is a form of chromatic aberration.

Coma is an inherent property of telescopes using parabolic mirrors. Unlike a spherical mirror, a bundle of parallel rays parallel to the optical axis will be perfectly focused to a point (the mirror is free of spherical aberration), no matter where they strike the mirror. However, this is only true if the rays are parallel to the axis of the parabola. When the incoming rays strike the mirror at an angle, individual rays are not reflected to the same point. When looking at a point that is not perfectly aligned with the optical axis, some of the incoming light from that point will strike the mirror at an angle. This results in an image that is not in the center of the field looking wedge-shaped. The further off-axis (or the greater the angle subtended by the point with the optical axis), the worse this effect is. This causes stars to appear to have a cometary coma, hence the name.

Coma (Pendulum song)

"Coma" is the third single by Australian ambient house band Pendulum. The single was released in July 1997 and peaked at #46 on the ARIA Singles Chart spending just 2 weeks on the Chart. It was later included on the album 3 Knocks and Triple J Hottest 100, 1997, where it ranked #32. It was the final single release from the band as they split in early 1998.

References

Revelation (Peter Andre album)

Revelation is the sixth studio album released by Australian singer-songwriter Peter Andre.

Background

Following a further three years away from the music industry, Andre had been quietly writing and recording new material. Andre was offered a recording contract with Conehead Management following the success of his ITV2 fly-on-the-wall documentary, Peter Andre: The Next Chapter. Andre began recording with Conehead in January 2009. On 9 August 2009, "Behind Closed Doors" was revealed as the first single from Andre's upcoming album. The track was co-written by Andre, AC Burrell and Francesca Richard. "Unconditional" was revealed as the second and final single from the album, due for release on 9 November 2009. However, the track had already charted on the UK Singles Chart, following promotion and download sales. Upon the physical release, the track peaked at #50, Andre's second lowest charting single to date. The video for the track premiered on The Box on 16 October 2009. The album itself was released on 19 September 2009, peaking at #3 on the UK Albums Chart, and selling more than 300,000 copies to be certified platinum. The album's tracklisting was confirmed via Play.com on 14 August 2009.

Austin John

HIDDEN ERROR: Usage of "spouse" is not recognized

Austin John Winkler (born October 25, 1981) is an American singer-songwriter best known for being the former lead singer of the American rock band Hinder. Winkler was one of the founding members of Hinder and recorded a total of one EP, four studio albums and released twenty-four singles to radio while with them during his 12-year tenure with the band. Since his departure from Hinder, Winkler has continued his career as a solo artist.

Winkler is set to release his first studio album as a solo artist titled Austin John in late 2015 to early 2016.

Time with Hinder 2001-2013

Before forming Hinder with alongside bandmates Cody Hanson and Joe "Blower" Garvey, Winkler sang in a Oklahoma City cover band up until July 2001. While playing at a college party, Winkler met Hanson and Garvey and shortly thereafter the three formed Hinder. Hinder released their debut EP titled Far From Close in 2003 under the independent label Brickden Records, the EP went on to sale around 5,000 copies.

Metro Station (album)

Metro Station is the eponymously titled debut length album by pop band Metro Station. The album was released on September 18, 2007 under Columbia/Red Ink.

Four singles were released from the album; "Shake It" and "Seventeen Forever" charted on the Billboard Hot 100. The album debuted at #189 on the U.S. Billboard 200, but reached a peak of #39 in June 2008. The single "Shake It" was certified Platinum in 2008. Since its release, Metro Station has sold approximately 400,000 copies in the United States.

The album was released in the UK on March 30, 2009. The version of the album released in the UK contains 2 exclusive bonus tracks including a brand new track, "After the Fall". The first UK single, "Shake It", was released a week before, on March 23, 2009.

Track listing

All songs written and composed by Metro Station, except "True to Me" by Metro Station, Sam Hollander and Dave Katz. 

Release history

Charts

Personnel

Girl

A girl is a female human from birth through childhood and adolescence to attainment of adulthood when she becomes a woman. The term girl may also be used to mean a young woman, and is often used as a synonym for daughter.

Etymology

The English word girl first appeared during the Middle Ages between 1250 and 1300 CE and came from the Anglo-Saxon words gerle (also spelled girle or gurle). The Anglo-Saxon word gerela meaning dress or clothing item also seems to have been used as a metonym in some sense.

Girl has meant any young unmarried woman since about 1530. Its first noted meaning for sweetheart is 1648. The earliest known appearance of girl-friend is in 1892 and girl next door, meant as a teenaged female or young woman with a kind of wholesome appeal, dates only to 1961.

Usage for adults

The word girl is sometimes used to refer to an adult female, usually a younger one. This usage may be considered derogatory or disrespectful in professional or other formal contexts, just as the term boy can be considered disparaging when applied to an adult man. Hence, this usage is often deprecative. It can also be used deprecatively when used to discriminate against children ("you're just a girl").