A Note on the Prehistory of Superheavy Elements
... suggest that it is “easy to conceive the existence of an upper limit to our existing system.” For x tending towards infinity, the result becomes 240, which is indeed in close agreement with the experimental value A = 239.70 known at the time. “Hence 240 can hardly fail to be a critical number in, an ...
... suggest that it is “easy to conceive the existence of an upper limit to our existing system.” For x tending towards infinity, the result becomes 240, which is indeed in close agreement with the experimental value A = 239.70 known at the time. “Hence 240 can hardly fail to be a critical number in, an ...
AST 207 Final Exam, Answers 15 December 2010
... P2=R3/M P=1year/(3e6)1/2 =0.58e-4year=5hour. 5. You are transported back in time to when the universe was 13 million years old and the expansion parameter was 1/100. a. (3 pts.) What was the temperature of the radiation from the Big Bang? (You must show your work.) What has a comparable temperature? ...
... P2=R3/M P=1year/(3e6)1/2 =0.58e-4year=5hour. 5. You are transported back in time to when the universe was 13 million years old and the expansion parameter was 1/100. a. (3 pts.) What was the temperature of the radiation from the Big Bang? (You must show your work.) What has a comparable temperature? ...
Elements Start Up Activities
... elements in the periodic table, the term "alkaline metal" refers only to Group 1 elements from lithium onwards. Period number: 1 Block: s-block ...
... elements in the periodic table, the term "alkaline metal" refers only to Group 1 elements from lithium onwards. Period number: 1 Block: s-block ...
Neutron Stars and Black Holes
... b)! Betelgeuse will not blow for >50 years. c)! Sirius is not going to supernova. d)! There are no supernova-candidates near enough to harm the Earth. e)! There is actually a chance since it has been 400 years since the last visible supernova. ...
... b)! Betelgeuse will not blow for >50 years. c)! Sirius is not going to supernova. d)! There are no supernova-candidates near enough to harm the Earth. e)! There is actually a chance since it has been 400 years since the last visible supernova. ...
THE NAMING OF STARS AND THE STUDY OF PROTOSTARS D. R.
... It is considered that stars are formed from protostars which are large clouds of material which mainly under gravity, coalesce to give 1, or 2 or 3 or more centres. Some of these centres are sufficiently large that they give stars. The result is that about 65% of stars are in binary systems and less ...
... It is considered that stars are formed from protostars which are large clouds of material which mainly under gravity, coalesce to give 1, or 2 or 3 or more centres. Some of these centres are sufficiently large that they give stars. The result is that about 65% of stars are in binary systems and less ...
File - Science Website
... Describe, in as much detail as you can, what forces allow a stable star to exist and how the star may eventually form a black hole. To gain full marks in this question you should write your ideas in good English. Put them into a sensible order and use the correct scientific words. ...
... Describe, in as much detail as you can, what forces allow a stable star to exist and how the star may eventually form a black hole. To gain full marks in this question you should write your ideas in good English. Put them into a sensible order and use the correct scientific words. ...
AY5 Homework for Quiz 4: Spring 2015
... 8. Which of the following are thought to be properties of or true of Dark Matter? __X__ it is “cold” (i.e. moves slowly compared to the speed of light) __X__ it does not readily interact directly ...
... 8. Which of the following are thought to be properties of or true of Dark Matter? __X__ it is “cold” (i.e. moves slowly compared to the speed of light) __X__ it does not readily interact directly ...
S E D
... additional constraints; chemical composition and hence mean molecular weight. The results we got out of the models showed that two parameters were very sensitive; the coulomb interaction in the EOS and the opacity. By adjusting these two parameters we have got the right fits, see fig. 11.10. As seen ...
... additional constraints; chemical composition and hence mean molecular weight. The results we got out of the models showed that two parameters were very sensitive; the coulomb interaction in the EOS and the opacity. By adjusting these two parameters we have got the right fits, see fig. 11.10. As seen ...
Lokal fulltext - Chalmers Publication Library
... the use of heterodyne spectrometers with resolving power, R =ν/∆ν, of up to 107 , corresponding to a velocity resolution (∆v = c ∆ν/ν) of 0.03 km s−1 . Hence, molecular lines allow us to study gas kinematics in high detail, and the line excitation probes the physical conditions of the gas. Observing ...
... the use of heterodyne spectrometers with resolving power, R =ν/∆ν, of up to 107 , corresponding to a velocity resolution (∆v = c ∆ν/ν) of 0.03 km s−1 . Hence, molecular lines allow us to study gas kinematics in high detail, and the line excitation probes the physical conditions of the gas. Observing ...
Fill in the blanks of each frame using the list of missing words given
... The diagrams are in the right order, but the descriptions to go with each one aren’t. Cut out each diagram and caption, and match the correct description to each diagram, and finish off each description. ...
... The diagrams are in the right order, but the descriptions to go with each one aren’t. Cut out each diagram and caption, and match the correct description to each diagram, and finish off each description. ...
laboratory analysis of presolar silicate stardust from a
... & Fegley 1995). Potential 30 Si-rich silicates must be produced before the third dredge-up raises C/O above unity. Only the M = 5 M star model with Z = 0.004 from the MONASH code yields a significant 30 Si excess (δ 30 Si = 854‰) at C/O = 1 (Zinner et al. 2006). Stars with M > 4 M are likely to ex ...
... & Fegley 1995). Potential 30 Si-rich silicates must be produced before the third dredge-up raises C/O above unity. Only the M = 5 M star model with Z = 0.004 from the MONASH code yields a significant 30 Si excess (δ 30 Si = 854‰) at C/O = 1 (Zinner et al. 2006). Stars with M > 4 M are likely to ex ...
Periodic Table - Fort Bend ISD
... We use visual and radio telescopes to observe objects in space. Visual Telescopes are called refracting and reflecting. Reflecting telescopes use mirrors and refracting telescopes use lenses to view objects far away. Radio telescopes detect the different wavelengths of objects in space. When looked ...
... We use visual and radio telescopes to observe objects in space. Visual Telescopes are called refracting and reflecting. Reflecting telescopes use mirrors and refracting telescopes use lenses to view objects far away. Radio telescopes detect the different wavelengths of objects in space. When looked ...
The First Stars in the Universe
... sources such as quasars. Future observations of distant objects may help determine when the universe’s helium was ionized. If the first stars were indeed very massive, they would also have had relatively short lifetimes—only a few million years. Some of the stars would have exploded as supernovae at ...
... sources such as quasars. Future observations of distant objects may help determine when the universe’s helium was ionized. If the first stars were indeed very massive, they would also have had relatively short lifetimes—only a few million years. Some of the stars would have exploded as supernovae at ...
What is a galaxy?
... Stellar populations: Old and new stars Stars formed at the time the Galaxy formed are called Population II stars. They are almost entirely hydrogen and helium with few heavier elements, because the matter in them had not previously been in another star. They lie in all parts of the galaxy, the halo ...
... Stellar populations: Old and new stars Stars formed at the time the Galaxy formed are called Population II stars. They are almost entirely hydrogen and helium with few heavier elements, because the matter in them had not previously been in another star. They lie in all parts of the galaxy, the halo ...
Stellar Winds and Supernova Remnants: Interaction with the ISM
... (left: composite NUV+FUV, right: FUV) showing wind - ISM interaction (field of view 62'x 62') Sahai & Chronopoulos (2010) ...
... (left: composite NUV+FUV, right: FUV) showing wind - ISM interaction (field of view 62'x 62') Sahai & Chronopoulos (2010) ...
Slide 1
... Very young clusters still contain very massive, very hot O and B stars, dominating the luminosity of the association and ionizing large regions of gas around them. ...
... Very young clusters still contain very massive, very hot O and B stars, dominating the luminosity of the association and ionizing large regions of gas around them. ...
an aluminum/calcium-rich, iron-poor, white dwarf star
... line by matching the measured and model EW (Table 2). Note that all [Z/H] given in Table 2 refer to the total abundance by number of a given element and not to the abundance of the listed neutral or ionic stage; the element abundances come from a weighted average of the abundances derived from indiv ...
... line by matching the measured and model EW (Table 2). Note that all [Z/H] given in Table 2 refer to the total abundance by number of a given element and not to the abundance of the listed neutral or ionic stage; the element abundances come from a weighted average of the abundances derived from indiv ...
Cosmological Structure Formation
... Note that from the ratio Nn/Np~ 1/6 we can already infer that if all neutrons would get incorporated into 4He nuclei, around 25% of the baryon mass would involve Helium ! Not far from the actual number ... ...
... Note that from the ratio Nn/Np~ 1/6 we can already infer that if all neutrons would get incorporated into 4He nuclei, around 25% of the baryon mass would involve Helium ! Not far from the actual number ... ...
Announcements Homework. Final Exam. Isotropy of the CMB
... brown dwarfs Î new low-mass stars (10 to 100 in existence per galaxy at any given time). • Occasional collisions of degenerate stars Î supernova. ...
... brown dwarfs Î new low-mass stars (10 to 100 in existence per galaxy at any given time). • Occasional collisions of degenerate stars Î supernova. ...
Beatrice Muriel Hill Tinsley
... numbers : its total mass, the fraction of gas turned into stars in each generation, the mix of mass formed and the age of the galaxy. And the output could be given as the time-history of the luminosity, colour, chemical composition, and residual gas mass of the model. The first happy result was that ...
... numbers : its total mass, the fraction of gas turned into stars in each generation, the mix of mass formed and the age of the galaxy. And the output could be given as the time-history of the luminosity, colour, chemical composition, and residual gas mass of the model. The first happy result was that ...
Stellar Evolu1on Stars spend most of their lives on the main
... Shell helium fusion increases the star’s luminosity -‐> causing stellar envelope to expand and cool again –> the star goes through a second red giant phase when it ascends the asympto,c giant ...
... Shell helium fusion increases the star’s luminosity -‐> causing stellar envelope to expand and cool again –> the star goes through a second red giant phase when it ascends the asympto,c giant ...
Unit 9E.1 The Life Cycle of Stars17213
... understand what they observe in space. Phoenix can make so many stars because its core is so cold. Astronomers say that the cluster’s center probably hides a super massive black hole, about as heavy as 10 billion suns smooshed together. Though it may be giant, that black hole is pretty quiet. But a ...
... understand what they observe in space. Phoenix can make so many stars because its core is so cold. Astronomers say that the cluster’s center probably hides a super massive black hole, about as heavy as 10 billion suns smooshed together. Though it may be giant, that black hole is pretty quiet. But a ...
Star G has an apparent magnitude of +5.0 and an absolute
... • O3 V star surrounded by a hydrogen cloud with a low free electron density • G2 V star surrounded a hydrogen cloud with a low free electron density • G2 V star surrounded a hydrogen cloud with a high free electron density • O3 V star surrounded by a hydrogen cloud with a high free electron density ...
... • O3 V star surrounded by a hydrogen cloud with a low free electron density • G2 V star surrounded a hydrogen cloud with a low free electron density • G2 V star surrounded a hydrogen cloud with a high free electron density • O3 V star surrounded by a hydrogen cloud with a high free electron density ...
evolution of low
... • H/He burning do not occur simultaneous, giant envelope but alternate → (convective) (R= 100 - 1000 RO. ) thermal pulsations ...
... • H/He burning do not occur simultaneous, giant envelope but alternate → (convective) (R= 100 - 1000 RO. ) thermal pulsations ...
Nucleosynthesis
Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons, primarily protons and neutrons. The first nuclei were formed about three minutes after the Big Bang, through the process called Big Bang nucleosynthesis. It was then that hydrogen and helium formed to become the content of the first stars, and this primeval process is responsible for the present hydrogen/helium ratio of the cosmos.With the formation of stars, heavier nuclei were created from hydrogen and helium by stellar nucleosynthesis, a process that continues today. Some of these elements, particularly those lighter than iron, continue to be delivered to the interstellar medium when low mass stars eject their outer envelope before they collapse to form white dwarfs. The remains of their ejected mass form the planetary nebulae observable throughout our galaxy.Supernova nucleosynthesis within exploding stars by fusing carbon and oxygen is responsible for the abundances of elements between magnesium (atomic number 12) and nickel (atomic number 28). Supernova nucleosynthesis is also thought to be responsible for the creation of rarer elements heavier than iron and nickel, in the last few seconds of a type II supernova event. The synthesis of these heavier elements absorbs energy (endothermic) as they are created, from the energy produced during the supernova explosion. Some of those elements are created from the absorption of multiple neutrons (the R process) in the period of a few seconds during the explosion. The elements formed in supernovas include the heaviest elements known, such as the long-lived elements uranium and thorium.Cosmic ray spallation, caused when cosmic rays impact the interstellar medium and fragment larger atomic species, is a significant source of the lighter nuclei, particularly 3He, 9Be and 10,11B, that are not created by stellar nucleosynthesis.In addition to the fusion processes responsible for the growing abundances of elements in the universe, a few minor natural processes continue to produce very small numbers of new nuclides on Earth. These nuclides contribute little to their abundances, but may account for the presence of specific new nuclei. These nuclides are produced via radiogenesis (decay) of long-lived, heavy, primordial radionuclides such as uranium and thorium. Cosmic ray bombardment of elements on Earth also contribute to the presence of rare, short-lived atomic species called cosmogenic nuclides.