If a main-sequence star is not too massive ( less than approximately 8 solar masses ), it will eventually shed enough mass to form a white dwarf having mass below the Chandrasekhar limit, which will consist of the former core of the star.

For more massive stars, electron degeneracy pressure will not keep the iron core from collapsing to very great density, leading to formation of a neutron star, black hole, or, speculatively, a quark star.

Since the Hubble sequence is entirely based upon visual morphological type, it may miss certain important characteristics of galaxies such as star formation rate ( in starburst galaxies ) and activity in the core ( in active galaxies ).

After a star has formed, it creates energy at the hot, dense core region through the nuclear fusion of hydrogen atoms into helium.

After the hydrogen fuel at the core has been consumed, the star evolves away from the main sequence on the HR diagram.

A star remains near its initial position on the main sequence until a significant amount of hydrogen in the core has been consumed, then begins to evolve into a more luminous star.

When nuclear fusion in the core of the star stops, the star collapses.

The gas falling inward either rebounds or gets so strongly heated that it expands outwards from the core, thus causing the star to explode.

When neutron star core material is presumed to consist mostly of free neutrons, it is typically referred to as neutron-degenerate matter in scientific literature.

In contrast, all proposed forms of neutron star core material are fluids and are extremely unstable at pressures lower than that found in stellar cores.

* In Larry Niven's Known Space fictional universe ( 1964 ), neutronium is actual neutron star core material.

As the core of a massive star is compressed during a supernova, and collapses into a neutron star, it retains most of its angular momentum.

As only 30 to 40 per cent of the gas in the cloud core forms stars, the process of residual gas expulsion is highly damaging to the star formation process.

In the Sun, deuterium-producing events are so rare ( diprotons, the much more common result of nuclear reactions within the star, immediately decay back into two protons ) that a complete conversion of the star's hydrogen would take more than ( ten billion ) years at the prevailing conditions of its core.

For at least a portion of its life, a star shines due to thermonuclear fusion of hydrogen into helium in its core, releasing energy that traverses the star's interior and then radiates into outer space.

Once the hydrogen fuel at the core is exhausted, a star with at least 0. 4 times the mass of the Sun expands to become a red giant, in some cases fusing heavier elements at the core or in shells around the core.

Meanwhile, the core becomes a stellar remnant: a white dwarf, a neutron star, or ( if it is sufficiently massive ) a black hole.

George Meredith has said that fervor is the core of style.

The burden of these reflections is that a broader unity among the free nations is at the core of our needs.

It is hypothesized that fertility is a function of the social system when the population as a whole is considered and a function of the subsystems when the two-fold division of core families and marginal families is considered.

but this is deceptive, for the core of membership is concentrated in a single social and economic stratum.

The congregation perishes when it is no longer possible to replenish that core from the neighborhood ; ;

moreover, residential mobility is so high in metropolitan areas that churches have to recruit constantly in their core stratum in order to survive ; ;

But where the core of NATO is concerned, the Secretary of State has not only reiterated the United States' profound attachment to the alliance, `` cornerstone '' of its foreign policy, but has announced that five nuclear submarines will eventually be at NATO's disposal in European waters.

That is, when Mr. Milstein thrust straight to the core of the music, sparks flying, bow shredding, violin singing, glittering and sometimes spitting, Mr. Hendl could go along.

It is a traditional virtue in many cultures, and a core aspect of various religious traditions, though the concept of ' others ' toward whom concern should be directed can vary among cultures and religions.

The general consensus amongst scholars is that Luwian was spoken — to a greater or lesser degree — across a large area of western Anatolia, including ( possibly ) Wilusa (= Troy ), the Seha River Land ( to be identified with the Hermos and / or Kaikos valley ), and the kingdom of Mira-Kuwaliya with its core territory of the Maeander valley.

The churches of the Anglican Communion have traditionally held that ordination in the historic episcopate is a core element in the validity of clerical ordinations.

* 1945 – Physicist Harry K. Daghlian, Jr. is fatally irradiated in a criticality accident during an experiment with the Demon core at Los Alamos National Laboratory.

Admission to any of the public universities in Arizona is ensured to residents in the top 25 % of their high-school class with a GPA of 3. 0 in core competencies.

Its purpose is to initialize the Amiga hardware and core components of AmigaOS and then attempt to boot from a bootable volume, such as a floppy disk or hard disk drive.

Along with tarot divination, astrology is one of the core studies of Western esotericism, and as such has influenced systems of magical belief not only among Western esotericists and Hermeticists, but also belief systems such as Wicca that have borrowed from or been influenced by the Western esoteric tradition.

The adrenal medulla is the core of the adrenal gland, and is surrounded by the adrenal cortex.

Bufotenin, an alkaloid from some toads, contains an indole core and is produced in living organisms from the amino acid tryptophan.

When a core electron is removed, leaving a vacancy, an electron from a higher energy level may fall into the vacancy, resulting in a release of energy.

ATM is a core protocol used over the SONET / SDH backbone of the public switched telephone network ( PSTN ) and Integrated Services Digital Network ( ISDN ), but its use is declining in favour of All IP.

As architectural forms evolved and centuries passed, the houses kept several core traits.

In 2008, the U. S. Supreme Court overturned a Washington, D. C. law that required handguns to be locked or otherwise kept inoperative within the home, saying that this " makes it impossible for citizens to use them for the core lawful purpose of self-defense.

In other instances where core data must or should be kept separate, the application designer typically carves up reserved storage areas into a number of sections equal to the number of I-streams.

When the ski was rotated on-edge, the aluminum sheets prevented the wooden core from twisting longitudinally, and kept much more of the ski's edge firmly pressed into the snow.

The incoming Democratic president Bill Clinton reappointed Alan Greenspan, and kept him as a core member of his economic team.

It would also activate a small neutron source kept at the center of the core, which would assure that the chain reaction began in earnest.

RiscPC augmented the ROM-based core OS with a disk-based directory structure containing configuration information, and some applications which had previously been kept in ROM.

This relatively small but high quality collection was kept in storage until 1965, when it again became public, as the core of the National Palace Museum in Taipei.

The contents of electronic memory were lost when power was disconnected, but core memory was non-volatile and kept its contents.

There sometimes exists two Books of Shadows kept by some traditional Wiccans, one being a book of core rituals and practises which remains unchanged and from which new initiates copy, and the second being a coven book, intended for ritual use, which differs from group to group and may contain much added material ( such as astrology, herbal lore, and information regarding divination ), and such material is often traded between covens.

In a depressurization fault, a gas-cooled reactor loses gas pressure within the core, reducing heat transfer efficiency and posing a challenge to the cooling of fuel ; however, as long as at least one gas circulator is available, the fuel will be kept cool.

Ironically, Bhutto was deliberately kept unaware about the progress of the nuclear complexes when country passed the milestone of manufacturing fissile core decades ago.

While most of the core of the team was kept intact, the Gunners brought in Dick Thornton and Mack Gladden from the University of Missouri.

It is also worth noting that most South Sudanese kept the core of their culture even while in exile and diaspora.

Aware of the ever-present danger of enemy raiders and the possibility of hit-and-run attacks, he kept the column in tight formation with a core of twelve mounted regiments, each with a hundred knights.

The CMOS 80c88 CPU has a static core, which means that it can be stopped simply by stopping the system clock oscillator that is driving it, and it will hold its state indefinitely and resume processing at the point it was stopped when the clock signal is restarted, as long as it is kept powered.

This plaster core has proved the greatest problem with long-term survival of Blue Amberol Records, as the plaster often tends to expand over the decades, especially if exposed to moisture or kept in humid conditions.

Although his critics claimed that many of the films that he had produced under the name of Rank were not exactly in keeping with his original intention of producing " family-friendly " movies to combat crass American commercial interests, he nevertheless kept to his core beliefs.

It is also worth noting that most South Sudanese kept the core of their culture even while in exile and diaspora.

After these opening concerts and until October 1999, Phil kept the same " core " of himself and Kimock, and generally Molo as well, while regularly rotating in new musicians on guitar and keys ( and sometimes additional instruments ).

Three of the safeguard control rods however were not inserted into the core and the fourth took abnormally long time, about 90 seconds, to slide back, while the power kept rising.

The remainder of the works formed the core of the Private Case which were kept hidden from readers in the British Library for many years ; they including a work by William Simpson Potter.

The items which were kept now form the core of the University of Dundee's D ' Arcy Thompson Zoology Museum, which can be found in the basement of the University's Carnelley Building and is open to the public on Friday afternoons in the summer, or by appointment.

Subsequent market developments like widespread adoption of 100 Gigabit Ethernet kept both competitors upping the ante in the core but did little to shift their relative shares.