Color index

In astronomy, the color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. The smaller the color index, the more blue (or hotter) the object is. Conversely, the larger the color index, the more red (or cooler) the object is. This is a consequence of the logarithmic magnitude scale, in which brighter objects have smaller (more negative) magnitudes than dimmer ones. For comparison, the yellowish Sun has a B–V index of 0.656 ± 0.005, whereas the bluish Rigel has a B–V of –0.03 (its B magnitude is 0.09 and its V magnitude is 0.12, B–V = –0.03).

To measure the index, one observes the magnitude of an object successively through two different filters, such as U and B, or B and V, where U is sensitive to ultraviolet rays, B is sensitive to blue light, and V is sensitive to visible (green-yellow) light (see also: UBV system). The set of passbands or filters is called a photometric system. The difference in magnitudes found with these filters is called the U-B or B–V color index, respectively.

BV

BV, B.V., Bv, bV, or bv may refer to:

Voiced labiodental affricate

A voiced labiodental affricate ([b̪͡v] in IPA) is a rare affricate consonant that is initiated as a voiced labiodental stop [b̪] and released as a voiced labiodental fricative [v].

Features

Features of the voiced labiodental affricate:

B. V. Rao

Banda Vasudev Rao was an Indian agriculturalist and poultry farmer, considered by many as the father of poultry farming in India. He was the founder chairman of the National Egg Coordination Committee (NECC) and was a 2004 inductee of the International Poultry Hall of Fame of the World Poultry Science Association. The Government of India awarded him the fourth highest civilian award of Padma Shri in 1990.

Biography

B. V. Rao was born in 1935, at Chanchalguda, in Hyderabad, in the undivided south Indian state of Andhra Pradesh (presently in Telangana). After working in many capacities such as a telephone operator, Railway police staff and as a personal secretary to a state minister, he joined Acharya N. G. Ranga Agricultural University, Rajendranagar, to successfully complete a training programme in dairy and poultry farming where he had the opportunity to learn under an American teacher, Moore. His first business venture was with 500 birds entrusted by Moore for tending and, soon, Rao started his own venture in a 7 acre plot, for which the funds were raised by selling the jewelry of his wife. The business, started in 1970, grew over the years to the present V H Group, a US$1 billion conglomerate with interests in Poultry, Meat, Pharmaceuticals, Cattle feed and Sports and has presence in India, Bangladesh, UK, Singapore, Vietnam and Brazil. They hold a 99.9 percent stake in the English Premier League team, Blackburn Rovers F.C., since 2010.