Is a dwarf star a real star?

[wonky]

With the definition of dwarf planets making them "not real planetsm," I've been wondering--are dwarf stars real stars?

 

[doubletruncation]

does it matter? <div class="Discussion_UserSignature"> </div>

 

[enigma10]

Yes. Often called a failed star.<br /><br />http://zebu.uoregon.edu/~soper/StarLife/browndwarfsS.html <div class="Discussion_UserSignature"> <em>"<font color="#333399">An organism at war with itself is a doomed organism." - Carl Sagan</font></em> </div>

 

[qso1]

One day the IAU may well be wrestling with this question. The question being "At what point is it called a planet or brown dwarf". There may even be some category between planet and brown dwarf. I consider dwarf planets to be planets, just smaller in size. Jupiter and Saturn have always been referred to as giants...or gas giants. The Sun is classified as a yellow dwarf star but its definetely a star.<br /><br />Two criteria will probably be used to define a star. Does it sustain nuclear fusion at its core. And does that fusion cause the star to emit its own light rather than reflect light as planets do? There was a scientist a couple years ago who suggested planets, namely Earth, may have fusion going on deep within their cores. Just not enough to cause the planet to ignite and become a star.<br /><br />It sounded plausible to me and could be the key to bridging planets and stars, but it is just theory at this point. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[alokmohan]

Our own sun is yellow dwarf.M type stars are dwarf stars.Brown dwarfs are in between jupiter and star.IAU has not become mad to sit for naming of dwarf stars

 

[qso1]

Exactly. I don't see that big a deal in dwarf planets for that reason. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[alokmohan]

Too much of pluto.Some dont know difference between dwarf star and dwarf planet.Let them do some home work.

 

[qso1]

I hear you there, LOL. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[silylene old]

<font color="yellow">One day the IAU may well be wrestling with this question. The question being "At what point is it called a planet or brown dwarf". There may even be some category between planet and brown dwarf. I consider dwarf planets to be planets, just smaller in size. Jupiter and Saturn have always been referred to as giants...or gas giants. The Sun is classified as a yellow dwarf star but its definetely a star. <br /><br />Two criteria will probably be used to define a star. Does it sustain nuclear fusion at its core. And does that fusion cause the star to emit its own light rather than reflect light as planets do? There was a scientist a couple years ago who suggested planets, namely Earth, may have fusion going on deep within their cores. Just not enough to cause the planet to ignite and become a star. <br /><br />It sounded plausible to me and could be the key to bridging planets and stars, but it is just theory at this point. </font><br /><br />If you read my definition of a planet (in another thread), I do think it should be limited by:<br />small enough mass to not sustain fusion (about <13 mass of Jupiter)<br /><i>and</i><br />composed primarily of "normal matter" (i.e. not degenerate matter, or a black hole, or neutron matter, or antimatter or anything other exotic substance we may discover in the future).<br /><br />As the mass of a planet increases, but still remains less than 13x Jupiter, some of the matter in the core become degenerate. Interestingly, this actually causes the diameter of the body to decrease. Somewhere about 5x to 10x Jupiter mass, the majority of the body's mass is degenerate matter. Brown dwarfs have a majority of degenerate matter.<br /><br />My definition that planets are composed primarily of "normal matter" would exclude brown dwarfs and other weird objects from being planets. Interestingly, this rather subtle but important issue is ignored by all the people who love to debate the definition of a planet but dwell o <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[vogon13]

If'n it be a fusin' hydrogen, it be's a star!<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[wonky]

Interesting discussion.<br /><br />Dwarf humans are real humans. Dwarf planets should be considered real planets, too. Even keep the definition the same, just don't call them "not real planets." If they aren't, then they should rename the category. Call them "plantinos" or something. LOL

 

[search]

Dwarf is a way to say same but different.<br /><br />http://en.wikipedia.org/wiki/Dwarf_star<br /><br />Dwarf star<br />A star whose state of evolution resembles that of the Sun. The term “dwarf star” derives from the work of Ejnar Hertzsprung and Henry Norris Russell, who distinguished two kinds of stars, large ones called giants (or supergiants) and smaller ones called dwarfs. The term “dwarf” is synonymous with “main sequence star” (luminosity class V) and implies not so much size as evolutionary condition. Dwarfs are stars that, like the Sun, fuse hydrogen into helium in their cores, the thermonuclear reactions providing energy and support. Dwarfs range over the entire spectral sequence. At the cool limit (where spectral class M converts to L), they have effective temperatures around 2000 K (3100°F), absolute visual magnitudes of +20, and bolometric luminosities of about 10?4 times the solar luminosity. At the hot O3 limit, the values are respectively 55,000 K (100,000°F), ?7, and over 106 solar. The Sun, a G2 dwarf, falls in the middle at 5780 K (9950°F) and an absolute visual magnitude of +4.83. These properties are produced by a mass range from 0.08 solar mass for warm L dwarfs, below which full hydrogen fusion cannot be turned on, to over 100 solar masses at class O3. See also Giant star; Hertzsprung-Russell diagram; Magnitude (astronomy); Sun.<br /><br />At the high-mass end, above about 10 solar masses, the dwarf stage lasts 2–20 million years, and O stars turn into supergiants and supernovae. At class G8 and a mass of 0.8 solar, the lifetime equals the age of the Milky Way Galaxy, and dwarfs between this limit and 10 solar masses become white dwarfs. See also Spectral type; Star; Stellar evolution; Stellar rotation; Supergiant star; Supernova; White dwarf star.<br /><br />From:<br />http://www.answers.com/topic/dwarf-star-1