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
List of Barbie's friends and family
The list of friends for the popular Barbie line of dolls that began in 1959. Since character continuity has not been consistent over time, there is no real "canon" lineup. At different times, different groups of dolls were offered, and the naming and apparent age relationships of the characters has varied considerably.
Barbie family and other principal characters
Summer (given name)
Summer is an English feminine given name of recent coinage derived from the word for the season of summer, the warmest season of the year and a time people generally associate with carefree and fun activities. It's been in common use as a name since at least 1970 in English-speaking countries. Summer, along with other seasonal and nature names, came into fashion as part of the 1960s and 70s counterculture.
The name was the 30th most common name given to girls born in England and Wales in 2011, was the 36th most popular name given to girls born in Scotland in 2011 and the 82nd most popular name for girls born in Northern Ireland in 2011. It was among the 10 most popular names given to baby girls born in 2008 in the Isle of Man. It also ranked as the 40th most popular name for baby girls born in New South Wales, Australia in 2011 and the 51st most popular name for girls born in British Columbia, Canada in 2011. It was the 173rd most popular name for girls born in the United States in 2011. It has ranked among the top 300 names for girls in the United States since 1970 and was the 648th most common name for girls and women in the United States in the 1990 census.
Summer (Tohoshinki EP)
"Summer: Summer Dream / Song for You / Love in the Ice" is Tohoshinki's 12th Japanese single. It was released on August 1, 2007 and debuted at #1 on the Oricon Daily Charts, ending as #2 overall for the week. It was TVXQ's first single in Japan to reach this position on the daily charts and was considered a milestone for the Korean boyband's rising popularity in Japan. With the success of the single, TVXQ won the Gold Artist Award in Best Hits 2007 Japan on November 26.
Live performances
Tracklisting
CD
DVD
Music video
The music video of "Summer Dream" features the members dancing in front of a pond, also their dancing with back up dancers, as the video goes on it shows scenes where Yuchun is driving a car and collecting the members, In the end the members are seen on beach when it comes to sunset.
Weekend (EP)
Weekend is the second studio EP of the New Zealand band Young Lyre, released on 25 November 2015.
Background
In the 2011, the band released their first EP, title Night Swimming. After a long period of tour and festivals, the band started to produce their second EP. On 24 May 2014, the band started their crowd funding campaign to help funding their second EP. The campaign of $2,000 meet its goal on 21 February 2015 with the total of $2,135. The EP was officially released on 27 November 2015.
Singles
The first single from the album, was "We Go Faster" released on 10 May 2015. The music video to the video was crowdfunded alongside the album production. Also they received the help to fund the video and the album by a New Zealand project called NZ On Air.
Track listing
All songs written and composed by Young Lyre.
Personal
Podcasts:
