Lecture 15 Star Formation and Evolution 3/7
... • if Mass(WD) > 1.4 M(Sun) degenerate electrons can not resist gravity called Chandrasekhar limit and no WD has a mass greater than this • If WD can acquire mass from companion star and goes over this limit Supernova and (usually) a Neutron Star ...
... • if Mass(WD) > 1.4 M(Sun) degenerate electrons can not resist gravity called Chandrasekhar limit and no WD has a mass greater than this • If WD can acquire mass from companion star and goes over this limit Supernova and (usually) a Neutron Star ...
The Physical Properties of Normal A Stars
... Binary star studies can lead to masses and also for eclipsing systems radii as well. The following values based on modern binary data from Harmanec (1988). ...
... Binary star studies can lead to masses and also for eclipsing systems radii as well. The following values based on modern binary data from Harmanec (1988). ...
MESSIER - EarthLink
... 1758, whilst observing the comet of that year. This nebula had such a resemblance to a comet in its form and brightness that I endeavored to find others, so that astronomers would no more confuse these same nebulae with comets just beginning to appear. I observed further with suitable refractors for ...
... 1758, whilst observing the comet of that year. This nebula had such a resemblance to a comet in its form and brightness that I endeavored to find others, so that astronomers would no more confuse these same nebulae with comets just beginning to appear. I observed further with suitable refractors for ...
Abundances of RGB stars in NGC 6752 Grundahl
... result of a process other than mixing, i.e., that the present abundance variations are of “primordial” origin. The primordial scenario, and variations on it, has been proposed and discussed several times before in the literature (see for example Cottrell & Da Costa 1981, and Cannon et al. 1998). The ...
... result of a process other than mixing, i.e., that the present abundance variations are of “primordial” origin. The primordial scenario, and variations on it, has been proposed and discussed several times before in the literature (see for example Cottrell & Da Costa 1981, and Cannon et al. 1998). The ...
3P15.pdf
... The excess emission is the surface flux obtained by subtracting the contribution of the photosphere to the total surface flux emitted by the star. Fig. 4a to 7a show, for all the stars of the sample, the mean value of the excess emission of the Hα line vs. the mean value of the excess emission of ot ...
... The excess emission is the surface flux obtained by subtracting the contribution of the photosphere to the total surface flux emitted by the star. Fig. 4a to 7a show, for all the stars of the sample, the mean value of the excess emission of the Hα line vs. the mean value of the excess emission of ot ...
First firm spectral classification of an early-B PMS star
... 6 F IRST FIRM SPECTRAL CLASSIFICATION OF AN EARLY-B PMS STAR : B275 IN M17 from the strong UV flux of the young massive star. On the other hand, to produce 1st overtone emission, CO must be excited, requiring a temperature in the range between 1500 and 4500 K (Bik & Thi 2004). This temperature migh ...
... 6 F IRST FIRM SPECTRAL CLASSIFICATION OF AN EARLY-B PMS STAR : B275 IN M17 from the strong UV flux of the young massive star. On the other hand, to produce 1st overtone emission, CO must be excited, requiring a temperature in the range between 1500 and 4500 K (Bik & Thi 2004). This temperature migh ...
Cepheid
... In Shapley’s day, the LMC and SMC were considered as two isolated offshoots of the Milky Way, different from the spiral nebulae. We now realize that they are ‘dwarf’ galaxies in their own right (but not spirals). ...
... In Shapley’s day, the LMC and SMC were considered as two isolated offshoots of the Milky Way, different from the spiral nebulae. We now realize that they are ‘dwarf’ galaxies in their own right (but not spirals). ...
5 Understanding stars and star ClUsters
... This compression action on the gas and dust causes pools and eddies to form, which are known as nebulae, and among these swirling collections of gas, stars begin to form. Some nebulae can condense and create dozens, some even thousands, of stars. These stars are still bound together gravitationally ...
... This compression action on the gas and dust causes pools and eddies to form, which are known as nebulae, and among these swirling collections of gas, stars begin to form. Some nebulae can condense and create dozens, some even thousands, of stars. These stars are still bound together gravitationally ...
The Sun and Stars 4.1 Energy formation and layers of the Sun 4.2
... An increase in the amount of sunspots (at sunspot maximums) generally means an increase in Solar Prominences and Solar Flares. It is important for us to follow the Sunspot cycle to know when there is going to be an increase in Sunspots, because they cause Solar Flares and Prominences. Although the ...
... An increase in the amount of sunspots (at sunspot maximums) generally means an increase in Solar Prominences and Solar Flares. It is important for us to follow the Sunspot cycle to know when there is going to be an increase in Sunspots, because they cause Solar Flares and Prominences. Although the ...
1.2.43The stellar populations of the Milky Way
... Unlike disc stars, Pop. II stars do not follow circular orbits, nor are they confined to the plane of the Galaxy. They move in eccentric orbits (see Figure 1.12), although still attracted to the Galactic centre, and may travel many kiloparsecs from the Galactic plane. This is of course consistent wi ...
... Unlike disc stars, Pop. II stars do not follow circular orbits, nor are they confined to the plane of the Galaxy. They move in eccentric orbits (see Figure 1.12), although still attracted to the Galactic centre, and may travel many kiloparsecs from the Galactic plane. This is of course consistent wi ...
The masses of stars
... If you ever dip a toe into the world of amateur astronomy, you rapidly run into the archaic measure we use for the brightness of stars, known as their magnitude. This measurement scale was originally devised by Hipparchus, a 2nd Century BC Greek astronomer who introduced it as a system to compare th ...
... If you ever dip a toe into the world of amateur astronomy, you rapidly run into the archaic measure we use for the brightness of stars, known as their magnitude. This measurement scale was originally devised by Hipparchus, a 2nd Century BC Greek astronomer who introduced it as a system to compare th ...
Galaxies (and stars) in the far infrared: results from the AKARI All
... Supply of metals to the interstellar space II: final life stages of stars The death of light stars : planetary nebulae (PNe) Stars with masses similar to the Sun run out the hydrogen in the core, change their equilibrium structure and expand, and become cool huge stars (red giant branch stars: RGBs ...
... Supply of metals to the interstellar space II: final life stages of stars The death of light stars : planetary nebulae (PNe) Stars with masses similar to the Sun run out the hydrogen in the core, change their equilibrium structure and expand, and become cool huge stars (red giant branch stars: RGBs ...
Deep Space Mystery Note Form 3
... Type II Type II Binary stars are when there are two stars and they revolve around each other. In these systems supernovas occur also. Stars up to eight times the mass of our sun usually evolve into white dwarfs. A star that is condensed to this size has a very strong gravitational pull. ...
... Type II Type II Binary stars are when there are two stars and they revolve around each other. In these systems supernovas occur also. Stars up to eight times the mass of our sun usually evolve into white dwarfs. A star that is condensed to this size has a very strong gravitational pull. ...
Encyclopedia of Optical Engineering Stellar Evolution
... full lifetime, typically measured in billions of years. Fig. 1 and Table 1 show the evolutionary tracks and time intervals for several solar mass values. As the protostar continues its slow contraction, the inner regions become quite hot (2000 – 3000 K) from the conversion of gravitational energy to ...
... full lifetime, typically measured in billions of years. Fig. 1 and Table 1 show the evolutionary tracks and time intervals for several solar mass values. As the protostar continues its slow contraction, the inner regions become quite hot (2000 – 3000 K) from the conversion of gravitational energy to ...
Stars 3
... collapsed core of the exploded star. The Crab Pulsar is a rapidly rotating neutron star – an object only about six miles across, but containing more mass than our Sun. As it rotates at a rate of 30 times per second the Crab Pulsar's powerful magnetic field sweeps around, accelerating particles, and ...
... collapsed core of the exploded star. The Crab Pulsar is a rapidly rotating neutron star – an object only about six miles across, but containing more mass than our Sun. As it rotates at a rate of 30 times per second the Crab Pulsar's powerful magnetic field sweeps around, accelerating particles, and ...
High-Speed Ballistic Stellar Interlopers
... indicates that the stars are traveling fast with respect to their surroundings—roughly five times faster than typical young stars. The interlopers were most likely ejected from massive star clusters. Assuming their youthful phase lasts only a million years and they are traveling 100,000 miles per ho ...
... indicates that the stars are traveling fast with respect to their surroundings—roughly five times faster than typical young stars. The interlopers were most likely ejected from massive star clusters. Assuming their youthful phase lasts only a million years and they are traveling 100,000 miles per ho ...
Evolution of a Planetary System
... Is Our Sun Unique? __________________________________________________________________ ...
... Is Our Sun Unique? __________________________________________________________________ ...
Corona Australis
Corona Australis /kɵˈroʊnə ɒˈstreɪlɨs/ or Corona Austrina /kɵˈroʊnə ɒˈstraɪnə/ is a constellation in the Southern Celestial Hemisphere. Its Latin name means ""southern crown"", and it is the southern counterpart of Corona Borealis, the northern crown. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations. The Ancient Greeks saw Corona Australis as a wreath rather than a crown and associated it with Sagittarius or Centaurus. Other cultures have likened the pattern to a turtle, ostrich nest, a tent, or even a hut belonging to a rock hyrax.Although fainter than its namesake, the oval- or horseshoe-shaped pattern of its brighter stars renders it distinctive. Alpha and Beta Coronae Australis are the two brightest stars with an apparent magnitude of around 4.1. Epsilon Coronae Australis is the brightest example of a W Ursae Majoris variable in the southern sky. Lying alongside the Milky Way, Corona Australis contains one of the closest star-forming regions to our Solar System—a dusty dark nebula known as the Corona Australis Molecular Cloud, lying about 430 light years away. Within it are stars at the earliest stages of their lifespan. The variable stars R and TY Coronae Australis light up parts of the nebula, which varies in brightness accordingly.