Dictionary
a star that ejects some of its material in the form of a cloud and become more luminous in the process
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Wikipedia
cleanup-date August 2005 alternateuses A nova is a cataclysmic nuclear explosion caused by the accretion of hydrogen onto the surface of a white dwarf star.When a white dwarf has a close companion star, the companion will often begin to have its outer atmosphere drawn away from it by the white dwarf's gravity as the companion star ages and expands into a red giant. The captured gases consist primarily of hydrogen and helium, the two principal constituents of matter in the universe. The gases are compacted on the white dwarf's surface by its intense gravity, compressed and heated to very high temperatures as additional material is drawn in. Eventually, the pressures and temperatures within the hydrogen layer becomes great enough to trigger a nuclear fusion reaction that rapidly converts a large amount of the hydrogen into helium and other heavier Chemical elementelements.The enormous amount of energy liberated by this process blows the remaining gases away from the white dwarf's surface and produces an extremely bright but brief-lived outburst of light. The ancients refused to believe that the "fixed stars" could show any changes, and considered these occurrences to be objects close to the earth. The astronomer Tycho Brahe observed the supernova SN 1572 in the constellation Cassiopeia, and described it in his book ''de stella nova'' (Latin for "concerning the new star"), giving rise to the name ''nova''. In this work he argued that a nearby object should be seen to move relative to the fixed stars, and that the nova had to be very far away.A white dwarf can potentially generate multiple novae over time as additional hydrogen continues to accrete onto its surface from its companion star. An example is RS Ophiuchi, which is known to have flared five times (in 1898, 1933, 1958, 1967, and 1985). Eventually, however, either the companion star will run out of material, or the white dwarf will undergo a nova so powerful that it is completely destroyed in the process. This is somewhat similar to a type Ia supernova. Supernovae in general, however, involve different processes as well as much higher energies, and should not be confused with ordinary novae.Occasionally a nova is bright enough and close enough to be conspicuous to the unaided eye. The most recent example was V1500 CygniNova Cygni 1975. This nova appeared on August 29, 1975 in the constellation Cygnus about five degrees north of Deneb and reached Apparent magnitudemagnitude 2.0 (nearly as bright as Deneb).
Bright novae since 1900 - Note:- Please add all Novae brighter than 6 mag ( !http://www.tsm.toyama.toyama.j p/curators/aroom/var/nova/1600 .htm? )
Recurrent novae - RS Ophiuchi T Coronae Borealis T Pyxidis
Notes - Under the Morgan-Keenan spectral classification scheme, novae are classified as ''Type-Q''.
See also - Cataclysmic variable Hypernova Nova remnant Supernova
External links - sai.msu.su - GVCSCategory:Novae Category:Astronomical !eventsCategory:AstrophysicsCat egory:Stellar? phenomenaca:Novade:Nova !(Stern)es:Novafi:Novafr:Novait :Novanl:Novaja:新星 ;pl:Nowaro:NovÄsv:Novazh: 032;星
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Websites
Mariner Cruises Whale & Seabird Tours
Mariner Cruises has been offering Nova Scotia whale watching and birding tours of the Bay of Fundy for nearly a decade. We invite you to join us for an exciting sea adventure from Brier Island, the Whale Watching Capital of Nova Scotia!
http://www.whalewatchingtours.info/
Nova Recordings
Mailorder, Distribution, Booking
http://www.novarecordings.de/
Atlantic Canada Cycling
Cycling information site for the Atlantic Provinces of Canada - Nova Scotia, Prince Edward Island, Newfoundland and Labrador, and New Brunswick
http://www.atlanticcanadacycling.com/
Pas Designs
Graphic design, fine art, airbrush art and more.
http://www.pas-designs.com/
KhushDC.org
KhushDC is a social, support and political group that provides a safe and supportive environment, promotes awareness and acceptance, and fosters positive cultural and sexual identity for lesbian, gay, bisexual, transgender, questioning (LGBTQ) and additional gender or sexual minority South Asians in the Washington, D.C. metropolitan area.
http://www.KhushDC.org/
Muscle Car Shirts
T-shirts with cool muscle car cartoon artwork by Vince Crain
http://www.vincecrain.com/ordershirt.html
NOVA-design
NOVA-design is professional Web design company that supplies services of web design and development, web application development, professional e-commerce systems (shopping cart, payment processing integration), Flash multimedia and graphics design.
http://www.nova-design.net/
PBS Online
This Web site from the Public Broadcasting Service (PBS) features companion Web sites for nearly 250 PBS programs and specials, as well as seven online neighborhoods that aggregate content by genre and interest.
http://www.pbs.org
National Organization for Victim Assistance
NOVA provides victim and witness assistance programs for practitioners, criminal justice agencies, professionals, former victims and survivors.
http://www.try-nova.org
Australian Academy of Science
Modeled after the Royal Society of London, the objects of the Academy are to promote Australian science through a range of activities.
http://www.science.org.au/
NOVA Chemicals
A petrochemicals company that focuses on commodity chemicals, producing olefins/polyolefins and styrenics at 18 facilities in the US, Canada, France and the UK.
http://www.novachem.com
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