Starship Asterisk*

When a Star reaches the end of its Giant stage, ie when it runs out of availiable Hydrogen, it implodes. If the mass of the Star is over 12 times the mass of the Sun it creates a Supernova with a Black Hole as its center. Below 12X limit it forms a Planetary Nebula. Below 1.4 times the Solar Mass it forms a White Dwarf then with time: a Red, Brown, then a Black Dwarf. Above 1.4X is a Neutron Star formed?

Philosophaie wrote:When a Star reaches the end of its Giant stage, ie when it runs out of available Hydrogen, it implodes. If the mass of the Star is over 12 times the mass of the Sun it creates a Supernova with a Black Hole as its center. Below 12X limit it forms a Planetary Nebula. Below 1.4 times the Solar Mass it forms a White Dwarf then with time: a Red, Brown, then a Black Dwarf. Above 1.4X is a Neutron Star formed?

That's the theory.

http://en.wikipedia.org/wiki/Neutron_star wrote:
<<A typical neutron star has a mass between 1.35 and about 2.0 solar masses.

In general, compact stars of less than 1.44 solar masses – the Chandrasekhar limit – are white dwarfs, and
above 2 to 3 solar masses (the Tolman-Oppenheimer-Volkoff limit), a quark star might be created; however, this is uncertain.

Gravitational collapse will usually occur on any compact star between 10 and 25 solar masses and produce a black hole.>>

neufer wrote:

Philosophaie wrote:When a Star reaches the end of its Giant stage, ie when it runs out of available Hydrogen, it implodes. If the mass of the Star is over 12 times the mass of the Sun it creates a Supernova with a Black Hole as its center. Below 12X limit it forms a Planetary Nebula. Below 1.4 times the Solar Mass it forms a White Dwarf then with time: a Red, Brown, then a Black Dwarf. Above 1.4X is a Neutron Star formed?

That's the theory.

http://en.wikipedia.org/wiki/Neutron_star wrote:
<<A typical neutron star has a mass between 1.35 and about 2.0 solar masses.

In general, compact stars of less than 1.44 solar masses – the Chandrasekhar limit – are white dwarfs, and
above 2 to 3 solar masses (the Tolman-Oppenheimer-Volkoff limit), a quark star might be created; however, this is uncertain.

Gravitational collapse will usually occur on any compact star between 10 and 25 solar masses and produce a black hole.>>

I am missing part of the range of solar masses. What happens between 3 and 10 solar masses besides producing a planetary nebula ? What is left behind ? What happens beyond 25 solar masses since recently discovered massive blue stars are determined to have 100 to 150 solar masses? Correct me if I am wrong, but all imploding stars produce either a supernova remnant, or a planetary nebula after the red giant stage ?

Doug Ettinger
Pittsburgh, PA
01/26/2011

I will answer my own questions after reviewing stellar evolution, planetary nebula, and some other topics. Please correct me
if the following summary is grievously incorrect.

Let M/o = solar mass.

1. Sub-stellar objects are less than 2.5 x 10(28) kg or 0.08 M/o and may be called planets.
2. Brown dwarfs range from 2.5 x 10(28) kg to 1.6 x 10(29) kg or greater than 13 Jupiter masses
3. Low-mass red dwarfs are from 1.6 x 10(29) kg to less than 0.5 M/o.
4. Mid-size yellow dwarfs are from 0.5 to 1.5 M/o.
5. Massive blue-white stars are from 1.5 to 10 M/o.
6. Super-massive stars are from about 10 to 120 M/o where outer layers no longer be retained due to the thermal energy.
7. Unusually super-super massive stars have been observed from 120 to 200 M/o. These stars are short-lived, have huge stellar winds, and continually blow-off their outer layers.

Hence, the summary of stellar remnants follows:

1. White dwarfs come from Main Sequence stars that are from 0.5 to 1.5 M/o and accompanied by red giants.
2. White dwarfs come from mass transfer in binary star systems are less than but not much greater than 1.4 M/o.
3. Neutron stars come from 1.35 to 2.0 M/o.
4. Quark stars come from 2.0 to 3.0 M/o. ( A recently new theory of neutrons breaking down into quarks.)
5. Black holes come any star greater than 3.0 M/o.
6. Planetary nebulae come from about 0.8 to 8.0 M/o.
7. Supernova remnants come from any star greater than 3.0 M/o.

Doug Ettinger, Pittsburgh, PA 02/01/11

Perhaps this is too much to follow for a reasoned response. Let me narrow the focus to items #5, #6, and #7 in the summary of stellar remnants. My review of current, appropriate references is not crystal clear about these topics. Can anybody help me become more sure about these items. Thanks.

Doug Ettinger, Pittsburgh, PA 02/04/11