Exotic Stars By Jason Fiola

Introduction Deciding on the Topic Searched Strange matter stars and Stranglings Heard about them from Dr. Antonio Padilla (University of Nottingham. Found out Strange Stars were part of a larger category Exotic Stars

Let’s Define an Exotic Star Some Definitions would include Neutron Stars and Pulsars. I’m going with the more strict definition, An Exotic Star is a compact Star composed of something other than electons, protons, and neutrons; and is balaced against gravitational collapse by degeneracy pressure and or other quantum properties.

Background Information For some background I’m going to cover 4 main types of exotic stars, Quark and Strange Stars Electroweak Stars Preon Stars Boson Stars (Ones I won’t cover but you might want to look up; Dark Stars and Glueballs. I LOVE some of these names.)

Strange and Quark Stars Quark stars, neutron stars and Black Holes all brought into existence in the same manner. Neutron stars Fight gravity with Degeneracy pressure If the star is too massive the Quarks that make up the neutrons (Two “up” one “down”) break apart. Giving free up and down Quarks. Soon these Quarks convert into strange Quarks Thus the name Strange Star or Strangling. Quark Stars fight gravity with Quark Degeneracy pressure. (Source: http://news.discovery.com/space/why-are-quark-stars-so-strange.htm)

Strange and Quark Stars Conventional thinking would lead us to believe Quark stars should be smaller than neutron stars Seems reasonable, Squish matter in tighter, of course it’s smaller. However new calculations suggest quarks stars actually might be bigger. Results suggest a 2.5 solar mass quark star would swell larger than a 2 solar mass neutron star. This can be used to try and find quark stars. (Source: http://news.discovery.com/space/why-are-quark-stars-so-strange.htm)

Strange and Quark Stars Pulsars RX J1856.5-3754 and 3C58 are possible Quark Stars Based on Observations released by the Chandra X-Ray Observatory April 10th 2002. These stars were previously thought to be Neutron Stars I have to assume these stars are probably in the 2.5 solar mass range. (Source: http://news.discovery.com/space/why-are-quark-stars-so-strange.htm)

Electroweak Stars We know that after large supernovae we can get, Neutron Star A Quark Star Black Hole Turns out there’s yet ANOTHER step in-between, THE ELECTROWEAK STAR (between a quark star and black hole) (Source:http://news.discovery.com/space/exotic-electroweak-star-predicted.htm)

Electroweak Stars An Electroweak star is so massive that it actually stars to act a little more like a conventional star. It actually starts to burn matter again This time It’s Quarks! Quarks are burnt/converted into Leptons Generating MASSIVE energy Shooting out tons of Neutrinos. (Source:http://news.discovery.com/space/exotic-electroweak-star-predicted.htm)

Electroweak Stars The outward pressure is just enough to keep the star from collapsing into a black hole. They’re called Electroweak Stars because, At such extreme conditions the Electromagnetic and weak forces become one. Just like shortly after the Big Bang. (Source:http://news.discovery.com/space/exotic-electroweak-star-predicted.htm)

Electroweak Stars The fact that the majority of radiation will be neutrinos means, Electroweak emit very few photons. Making them almost impossible to observe. Make these stars a decent candidate to account for some Dark Matter. (Source:http://news.discovery.com/space/exotic-electroweak-star-predicted.htm)

Preon Stars Preon Stars are really cool.. But also SUPER complicated.. Theoretical type of star Made of Preons Again a theoretical subatomic particle. Go from Atom > Proton > Quark > Preon.. Maybe.. They are an alternative to Strings. (Source: http://www.dailygalaxy.com/my_weblog/2009/08/preons-splitting-the-quark-because-subatomic-physics-wasnt-complicated-enough.html )

Preon Stars Expected to have MASSIVE densities Exceeding 1023Kg/M3 Greater density than a Quark Star. Yet Smaller and lighter than a White Dwarf and Neutron Stars. Expected to originate from supernovae or the big bang. (Source: http://en.wikipedia.org/wiki/Exotic_star)

Preon Stars These objects in principle could be detected through gravitational lensing of Gamma Rays. Preon stars are once again another candidate for Dark Matter. However there is much doubt in the existence of preons in the first place. (Source: http://en.wikipedia.org/wiki/Exotic_star)

Preon Stars For a Preon star to exist and NOT become a Black Hole, The Radius: <40m Mass: <0.013 Solar Masses (Source: http://en.wikipedia.org/wiki/Exotic_star)

Boson Stars Another Hypothetical or Theoretical Star Formed of Bosons Conventional stars are formed of Fermions. Bosons are particles with integer spins (0, 1, 2…) All Force carrier particles are Bosons Mesons are too. Fermions Leptons & Quarks (Source: http://www.particleadventure.org/fermibos.html)

Boson Stars To exist, There must exist a stable type of boson Must also possess a small mass No current evidence of such a star However in the coming years it is possible to dectect such a star By gravitational radiation emitted by a pair of orbiting Boson Stars. (Source: http://en.wikipedia.org/wiki/Exotic_star )

Boson Stars Are thought to only be created during the primordial stages of the Big Bang Theory Once again a candidate for Dark Matter Objects In theory a Super Massive Boson Star could exist in a galactic core May explain many observed properties of active galactic cores. (Source: http://en.wikipedia.org/wiki/Exotic_star )

Boson Star and Dark Matter (Paper 1) Solves Einstein-Klein-Gordon Equations Figure out many different possible bosonic configurations Did it Geometrically Motivation Obtain an exact solution Show how they can account for missing Dark Matter (Sharma, R.)

Electroweak Stars: How Nature May Capitalize on the Standard Model’s Ultimate Fuel. (Paper 2) Studied the possible existence of an electroweak star Found solution to Tolman-Oppenheimer-Volkoff equations describing such an object. Their model suggest lifetime of quasi-equilibrium (Quark Burning vs. Gravity) More than 10,000,000 years. (De-Chang Dail.)

Chandra X-Ray Observatory, Cosmic X-Rays Reveal Evidence For New Form of Matter (Press release.) This press release was about the two stars I mentioned earlier, RX J1856.5-3754 (refer to as RX from now on.) 3C58 RX was found to radiate at 700,000*C with a diameter of 11.3Km Too hot and too small to be a neutron star. (Contradicts earlier point… must be variable I’m unaware of) Thought to be a Quark Star. (Source: http://chandra.harvard.edu/press/02_releases/press_041002.html )

Chandra X-Ray Observatory, Cosmic X-Rays Reveal Evidence For New Form of Matter (Press release.) 3C58 interestingly enough was the supernova observed by Chinese and Japanese Astronomers in 1181. This star was previously thought to be a neutron star Now thought to possibly be a quark star as-well. (Source: http://chandra.harvard.edu/press/02_releases/press_041002.html )

Sources Dr. Antonio Padilla, University of Nottingham, (Source: http://www.nottingham.ac.uk/~ppzphy7/webpages/people/antonio_padilla/) Source: http://en.wikipedia.org/wiki/Exotic_star Source: http://news.discovery.com/space/why-are-quark-stars-so-strange.htm Source: http://news.discovery.com/space/exotic-electroweak-star-predicted.htm Source: http://www.dailygalaxy.com/my_weblog/2009/08/preons-splitting-the-quark-because-subatomic-physics- wasnt-complicated-enough.html Source: http://www.particleadventure.org/fermibos.html Source: http://chandra.harvard.edu/press/02_releases/press_041002.html De-Chang Dai et al., (2009) "Electroweak stars: how nature may capitalize on the standard model's ultimate fuel"". arXiv:0912.0520 Sharma, R.; Karmakar, S.; Mukherjee, S. (2009) "Boson star and dark matter". arXiv.