Symbiotic novae star

Symbiotic novae star

" "Symbiotic novae occur in double star systems, where mass lost by a red giant is accumulated by wind accretion onto a wite dwarf. When a critical mass has been reached, a nova-like outburst of long duration sets in, the outbursts lasts many dozons of years. We determine the evolution of luminosity and temperature during the outburst. We find slowly increasing temperatures, up to 200 000 K. Peak luminosities are in the range L = 104.0 ± 0.5 solar luminosity. Symbiotic novae remain at such a level for at least one decade. A significant decline in luminosity is observed in the three oldest objects. The total radiation output of a symbiotic nova is of the order of 1047 erg. This exceeds the energy set free in classical novae. From all eruptive stellar events only supernovae are more energetic than symbiotic novae. For the accreting star the core-mass luminosity relation gives white dwarfs masses in the range 0.6 less than M/solar mass less than 1.2. We also find the the white dwarfs in symbiotic nova systems are unlikely to reach the Chandrasekhar mass limit. We find that the relative slowness in the intitial brightness increase of symbiotic novae need not necessarily be due to a slow thermonuclear event. In the appropriate environment it can just as well be due to the time needed for the expansion and growth of the ionization front. Two of our objects may qualify for that possibility. For deriving the temperature of the ionizing source in a photo-ionized gaseous nebula we suggest a formula of the form T* (1000 K) = chimax (eV), where chimax is the highest observed ionization potential." "

Reference

*

*
* [http://www.maik.ru/abstract/letters/8/letters0474_abstract.pdf Photometric and Spectroscopic Evolution of the Symbiotic Nova ...]

*

*


Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Symbiotic variable star — A Symbiotic Variable star is a variable binary star system in which one star has expanded its outer envelope and is shedding mass quickly, and another hot star (often a white dwarf) is ionizing the gas [… …   Wikipedia

  • Binary star — For the hip hop group, see Binary Star (band). Hubble image of the …   Wikipedia

  • Variable star — A star is classified as variable if its apparent brightness as seen from Earth changes over time, whether the changes are due to variations in the star s actual luminosity, or to variations in the amount of the star s light that is blocked from… …   Wikipedia

  • Compact star — In astronomy, the term compact star (sometimes compact object) is used to refer collectively to white dwarfs, neutron stars, other exotic dense stars, and black holes. These objects are all small for their mass. The term compact star is often… …   Wikipedia

  • Nova — For other uses, see Nova (disambiguation). Artist s conception of a white dwarf star accreting hydrogen from a larger companion A nova (plural novae) is a cataclysmic nuclear explosion in a star caused by the accretion of hydrogen on to the… …   Wikipedia

  • White dwarf — For other uses, see White dwarf (disambiguation). Image of Sirius A and Sirius B taken by the Hubble Space Telescope. Sirius B, which is a white dwarf, can be seen as a faint pinprick of light to the lower left of the much brighter Sirius A …   Wikipedia

  • Dwarf nova — HT Cas seen in outburst (mag 13.4) on 2010 November 2. Li …   Wikipedia

  • Astronomical object — Celestial object and Celestial body redirect here. For other uses, see Celestial (disambiguation). This article is about naturally occurring objects. For artificial objects, see Satellite. Astronomical objects or celestial objects are naturally… …   Wikipedia

  • Röntgendoppelstern — Künstlerische Darstellung eines Röntgendoppelsterns mit Akkretionsscheibe und Jet Ein Röntgendoppelstern ist ein Doppelsternsystem, das Röntgenstrahlung abstrahlt aufgrund der Umwandlung von potentieller Energie in elektromagnetische Strahlung.… …   Deutsch Wikipedia

  • List of astronomy acronyms — This is a compilation of acronyms commonly used in astronomy. Most of the acronyms are drawn from professional astronomy and are used quite frequently in scientific publications. However, a few of these acronyms are frequently used by the general …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”