Two of the most important are Cepheid variable stars and type 1A supernovae. One suggestion put forth is the common envelope ejection in a merger of a WD and an Asymptotic Giant Branch (AGB) star . The energy released in the explosion also causes an extreme increase in luminosity. (Phys.org)—Using gravitational lensing, an international team of astronomers has detected a new Type Ia supernova. Cepheids are what Edwin Hubble used to determine the distances of “nebulae” (ie.

2. Type 1A supernovae

Figure 07 is a Type Ia supernova observed in 1994. Supernovae rival entire galaxies in brightness for weeks. A similar scenario may explain type IIa supernovae, a rare class that have spectra of type Ia at early times but later transition to type IIn (but much less luminous than SN 2006gy).

When enough gas builts up on the surface of the white dwarf it triggers an explosion. same amount of energy, and studies of relatively nearby type Ia supernovae have shown that they reach almost the same peak brightness in every case. 20. For a brief time, the system can shine up to a million times brighter than Therefore it can be used as "standard candles" to determine their true distance. a. light curves and the detection of energetic cosmic rays b. light curves and the detection of neutrons c. light curves and the detection of radio pulses d. spectra and light curves e. spectra and X-ray emission ANS: D DIF: Easy REF: 17.2 MSC: Remembering OBJ: Differentiate Type Ia and Type II supernovae. galaxies) and derive the Hubble law.

They tend to fade over months or years. the fact that type la supernovae are dimmer than predicted is strongest evidence for dark energy T one of the possible explanation for dark energy is called, proposed that the universe is filled with a dearying and casuing the explanion to speed up During the supernova, a tremendous amount of energy is released. [12] Whether or not the supernova remnant remains bound to its companion depends on the amount of mass ejected The typical visual absolute magnitude of Type Ia supernovae is Mv = −19.3 (about 5 billion times brighter than the Sun), with little variation.

It is the bright spot on the lower left at the fringe of the galaxy. A nova is an explosion from the surface of a white-dwarf star in a binary star system. There are several types of 'standard candle' objects for which we can predict the luminosity from some other measurement. Type I and Type II supernovae can be distinguished by what combination of observations? A nova occurs when the white dwarf, which is the dense core of a once-normal star, “steals” gas from its nearby companion star.

Some of that energy is used …

Supernovae are really bright -- about 10 billion times as luminous as the Sun.