betelgeuse and the red supergiants
... it will end as a core-collapse supernova leaving a neutron star or black hole. But do we know that it is? If Betelgeuse were to be a lower-mass super-Asymptotic Giant Branch (super-AGB) star it would end up as an electron-capture supernova or die a less spectacular death leaving behind an oxygen-neo ...
... it will end as a core-collapse supernova leaving a neutron star or black hole. But do we know that it is? If Betelgeuse were to be a lower-mass super-Asymptotic Giant Branch (super-AGB) star it would end up as an electron-capture supernova or die a less spectacular death leaving behind an oxygen-neo ...
Can Extra Mixing in RGB and AGB Stars Be Attributed to Magnetic
... (Eddington 1925; Sweet 1950). Meridional circulation in a radiatively stratified star implies a transport of angular momentum that drives a state of differential rotation. According to studies performed by Spruit (1999, 2002) on the basis of previous work by Tayler (1973), such a differential rotati ...
... (Eddington 1925; Sweet 1950). Meridional circulation in a radiatively stratified star implies a transport of angular momentum that drives a state of differential rotation. According to studies performed by Spruit (1999, 2002) on the basis of previous work by Tayler (1973), such a differential rotati ...
A Walk through the Southern Sky: A Guide to Stars and
... and street lamps may prevent you from seeing as many stars as you could if your surroundings were in total darkness. Remember, magnitude is a measure of ...
... and street lamps may prevent you from seeing as many stars as you could if your surroundings were in total darkness. Remember, magnitude is a measure of ...
Circumstellar Material in Young Stellar Objects
... which collapse under the influence of their own gravity. However, after more than two centuries of research many important questions regarding the star formation process, and the fundamentals of planet formation, still remain unanswered. Nonetheless, the rapid progress in our knowledge of star forma ...
... which collapse under the influence of their own gravity. However, after more than two centuries of research many important questions regarding the star formation process, and the fundamentals of planet formation, still remain unanswered. Nonetheless, the rapid progress in our knowledge of star forma ...
Determination of the distance to the Andromeda Galaxy using variable stars U
... up similarities and differences between solar and stellar flares is to continuously broaden the ensemble of analyzed flares (solar and stellar as well), thus making an observational base of different types of flaring activities available for theoretical purposes. This is how solar flare observations c ...
... up similarities and differences between solar and stellar flares is to continuously broaden the ensemble of analyzed flares (solar and stellar as well), thus making an observational base of different types of flaring activities available for theoretical purposes. This is how solar flare observations c ...
Circumstellar dust emission from nearby Solar
... flux increases which clears its surroundings from most of the gas and dust, and only planets of different sizes and rings of planetesimals remain. These rings of planetesimals are important for the circumstellar dust that are discussed in this thesis. Gravitational influences from surrounding planet ...
... flux increases which clears its surroundings from most of the gas and dust, and only planets of different sizes and rings of planetesimals remain. These rings of planetesimals are important for the circumstellar dust that are discussed in this thesis. Gravitational influences from surrounding planet ...
Non-conservative mass transfers in Algols
... (2001). In this study, 18 of these Algols, showing only parabolic O−C diagrams, were selected in order to investigate their orbital period changes and apply the revised model of non-conservative mass transfer. The SD parameter in Table 1 is a crude probability indicator for binaries having an SD nat ...
... (2001). In this study, 18 of these Algols, showing only parabolic O−C diagrams, were selected in order to investigate their orbital period changes and apply the revised model of non-conservative mass transfer. The SD parameter in Table 1 is a crude probability indicator for binaries having an SD nat ...
Challenges in Planet Formation
... star1 . A disk that is solely heated by the star is called a passive disk (Chiang and Goldreich, 1997; Dullemond et al., 2001, 2002). A passive disk is very cold throughout its evolutionary stages, until it becomes transparent to the stellar irradiation. Chiang and Youdin (2010) estimated that ...
... star1 . A disk that is solely heated by the star is called a passive disk (Chiang and Goldreich, 1997; Dullemond et al., 2001, 2002). A passive disk is very cold throughout its evolutionary stages, until it becomes transparent to the stellar irradiation. Chiang and Youdin (2010) estimated that ...
the bible and the pleiades
... view of a basic Bible truth, he carried it too far. As for me, I am not prepared to write a treatise on the stars as found in the Holy Bible. Still, we will see many of these stellar elements in the facts and lore of the Pleiades. But first, a bit about that lovely jewel in the sky. The Pleiades as ...
... view of a basic Bible truth, he carried it too far. As for me, I am not prepared to write a treatise on the stars as found in the Holy Bible. Still, we will see many of these stellar elements in the facts and lore of the Pleiades. But first, a bit about that lovely jewel in the sky. The Pleiades as ...
Using time to measure distance - AS-A2
... 11. In the 1920s. Vesto Slipher and Edwin Hubble gathered data that showed that distant galaxies are all moving away from us and that the speed at which they are moving away is directly proportional to their distance. How do cosmologists account for these observations? ...
... 11. In the 1920s. Vesto Slipher and Edwin Hubble gathered data that showed that distant galaxies are all moving away from us and that the speed at which they are moving away is directly proportional to their distance. How do cosmologists account for these observations? ...
Cold versus Warm Dark Matter Simulations of a Galaxy Group
... large-scale clustering of galaxies observed in sky surveys (such as the SDSS or 2DF). These measurements probe the power spectrum on scales much greater than those scales where the nature of the dark matter can be probed. A number of suggestions as to the mass of DM particles have recently been prop ...
... large-scale clustering of galaxies observed in sky surveys (such as the SDSS or 2DF). These measurements probe the power spectrum on scales much greater than those scales where the nature of the dark matter can be probed. A number of suggestions as to the mass of DM particles have recently been prop ...
Chapter 5 The Evolutionary Paths Of Nearby Galaxies
... misclassified or peculiar objects and their properties will be investigated later. To investigate whether the quenching is due to AGN feedback or environmental effects, I divide the sample according to nuclear activity and Hi content (Figure 5.1, top row, central and right panel, respectively), as d ...
... misclassified or peculiar objects and their properties will be investigated later. To investigate whether the quenching is due to AGN feedback or environmental effects, I divide the sample according to nuclear activity and Hi content (Figure 5.1, top row, central and right panel, respectively), as d ...
Beyond simple depletion: phase behaviour of colloid–star polymer
... of increasing functionality (number of arms). To simplify the terminology, we will refer to the model system and the more complex systems just introduced as the colloid–polymer mixture and the colloid–star mixture, respectively. Moreover, when ‘polymer’ is used without qualification, it refers to a l ...
... of increasing functionality (number of arms). To simplify the terminology, we will refer to the model system and the more complex systems just introduced as the colloid–polymer mixture and the colloid–star mixture, respectively. Moreover, when ‘polymer’ is used without qualification, it refers to a l ...
The AG Carinae nebula: abundant evidence for a red supergiant
... High-resolution spectroscopy of the AG Car nebula shows that it is a hollow expanding shell with an expansion velocity of 70 km s-1 (Smith 1991; Nota et al. 1992) and a dynamical age of 8500 yr. Nota et al. (1992) derive an ionized nebular mass of 4.2M0 from the intregrated Ha flux. These parameters ...
... High-resolution spectroscopy of the AG Car nebula shows that it is a hollow expanding shell with an expansion velocity of 70 km s-1 (Smith 1991; Nota et al. 1992) and a dynamical age of 8500 yr. Nota et al. (1992) derive an ionized nebular mass of 4.2M0 from the intregrated Ha flux. These parameters ...
Accreting magnetars: a new type of high-mass X-ray binaries? P. Reig,
... 3 T H E S P I N - P E R I O D E VO L U T I O N Prior to the determination of the spin period, we converted the arrival times to the Solar system barycentre. Then we generate a light curve in the 0.2–12 keV energy range with a bin size of 10 s. The last ∼2300 s of the light curve were affected by hig ...
... 3 T H E S P I N - P E R I O D E VO L U T I O N Prior to the determination of the spin period, we converted the arrival times to the Solar system barycentre. Then we generate a light curve in the 0.2–12 keV energy range with a bin size of 10 s. The last ∼2300 s of the light curve were affected by hig ...
Migrating Dust Particles
... size they drifted towards the Sun. This material was later accreted to planetesimals which are held together by self-gravity. As the planetesimals extend their gravitational range they have a run-away growth towards becoming planets. In this step the planetesimals grow more the larger they get. This ...
... size they drifted towards the Sun. This material was later accreted to planetesimals which are held together by self-gravity. As the planetesimals extend their gravitational range they have a run-away growth towards becoming planets. In this step the planetesimals grow more the larger they get. This ...
Student copy of notes - User Web Areas at the University of York
... Eventually a neutron star is formed if the core is less than three solar masses. Neutron stars are incredibly dense - similar to the density of an atomic nucleus. They are typically 20 km across but more massive than the Sun. Because they contain so much mass within such a small volume, the gravitat ...
... Eventually a neutron star is formed if the core is less than three solar masses. Neutron stars are incredibly dense - similar to the density of an atomic nucleus. They are typically 20 km across but more massive than the Sun. Because they contain so much mass within such a small volume, the gravitat ...
The hot-Jupiter Kepler-17b: discovery, obliquity from stroboscopic
... The IMF prior changes the final answer by less than half a σ for all parameters. We then incorporate this likelihood by discarding members of the chain according to their weight, where the weight is equal to the likelihood of remaining sampling; about 40% of the original chain remains intact after t ...
... The IMF prior changes the final answer by less than half a σ for all parameters. We then incorporate this likelihood by discarding members of the chain according to their weight, where the weight is equal to the likelihood of remaining sampling; about 40% of the original chain remains intact after t ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.