Galaxies
... • The first formation was about 13 billion years ago. • Gravity pulled small gas clouds together—with enough density, stars form. • These first galaxies were elliptical shapes. ...
... • The first formation was about 13 billion years ago. • Gravity pulled small gas clouds together—with enough density, stars form. • These first galaxies were elliptical shapes. ...
PowerPoint
... High-mass star forming regions are much more distant (in average) than those of low-mass stars (high-mass: 3-7kpc vs. low-mass: 0.1-0.3 kpc) OB stars - form preferentially in the centre of dense star clusters - seem to live pref. in (tight) binary and higher order systems ...
... High-mass star forming regions are much more distant (in average) than those of low-mass stars (high-mass: 3-7kpc vs. low-mass: 0.1-0.3 kpc) OB stars - form preferentially in the centre of dense star clusters - seem to live pref. in (tight) binary and higher order systems ...
Name: Hour:______ Directions for website use: This web activity is
... Click “Next”: 12. Hot stars put out their peak radiation at_____________? 13. What is the color of a star that has a temperature of 30,000 degrees? ______________ 14. Why does a star appear blue when it also emits green and red light? The star appears blue because its peak wavelength is in the porti ...
... Click “Next”: 12. Hot stars put out their peak radiation at_____________? 13. What is the color of a star that has a temperature of 30,000 degrees? ______________ 14. Why does a star appear blue when it also emits green and red light? The star appears blue because its peak wavelength is in the porti ...
Stellar Spectra Classification
... Introduction: Classifying stars based on brightness is somewhat problematic. A star’s apparent brightness can be affected by its distance from the observer, its size, or by the presence of interstellar dust. Instead, astronomers classify stars based on the major components of their spectra. Much lik ...
... Introduction: Classifying stars based on brightness is somewhat problematic. A star’s apparent brightness can be affected by its distance from the observer, its size, or by the presence of interstellar dust. Instead, astronomers classify stars based on the major components of their spectra. Much lik ...
b) Formation of Heavy Elements
... Elements heavier than Iron get created during Supernova Explosions. Since there are two types of supernovae (SN I and SN II — the end stage of a low mass binary and the end stage of a high mass single star), the details are a little different, but the general process is the same. Prior to the explos ...
... Elements heavier than Iron get created during Supernova Explosions. Since there are two types of supernovae (SN I and SN II — the end stage of a low mass binary and the end stage of a high mass single star), the details are a little different, but the general process is the same. Prior to the explos ...
Chemical Evolution of the Galaxy and its satellites
... • The SFR is the star formation rate (how many solar masses go into stars per unit time) • The IMF is the initial stellar mass function describing the distribution of stars as a function of stellar mass ...
... • The SFR is the star formation rate (how many solar masses go into stars per unit time) • The IMF is the initial stellar mass function describing the distribution of stars as a function of stellar mass ...
How to Detect Black Holes
... according to Schödel in his paper, after applying the appropriate Plummer distribution to each of the three models, they would all collapse to a single black hole after only 100,000 years. This is much too short a time to be feasible, so those three theories are safely eliminated. There were two oth ...
... according to Schödel in his paper, after applying the appropriate Plummer distribution to each of the three models, they would all collapse to a single black hole after only 100,000 years. This is much too short a time to be feasible, so those three theories are safely eliminated. There were two oth ...
Head-On Collision of Neutron Stars As A Thought Experiment
... endpoint configuration and cease all further contraction. If its rest mass exceeds the critical value it must ultimately undergo catastrophic collapse to a Schwarzschild ...
... endpoint configuration and cease all further contraction. If its rest mass exceeds the critical value it must ultimately undergo catastrophic collapse to a Schwarzschild ...
Solar System
... objective of focal length 1200 mm using two different eyepieces with focal lengths of: (a) 25 mm (b) 10 mm (a) Magnification = 1200/25 = 48x (b) Magnification = 1200/10 = 120x ...
... objective of focal length 1200 mm using two different eyepieces with focal lengths of: (a) 25 mm (b) 10 mm (a) Magnification = 1200/25 = 48x (b) Magnification = 1200/10 = 120x ...
2.1 Hubble Space Telescope
... The galaxy I Zwicky 18 appears to look older the more astronomers study it. The galaxy’s youthful appearance was identified some 40 years ago through observations at the Palomar Observatory. Those studies showed that the galaxy erupted with star formation billions of years after its galactic neighbo ...
... The galaxy I Zwicky 18 appears to look older the more astronomers study it. The galaxy’s youthful appearance was identified some 40 years ago through observations at the Palomar Observatory. Those studies showed that the galaxy erupted with star formation billions of years after its galactic neighbo ...
Unique observations of a newborn star provide information on the
... the discovery of a new star is an extremely rare event, having occurred only twice in the last century. What made this star even more special was the fact that it appears to be an extremely young star – far less than a million years old – about the same mass as the sun. Astronomers know of fewer Dav ...
... the discovery of a new star is an extremely rare event, having occurred only twice in the last century. What made this star even more special was the fact that it appears to be an extremely young star – far less than a million years old – about the same mass as the sun. Astronomers know of fewer Dav ...
Information Worksheet The Life of a Star
... into a huge globule of gas and dust which contracts under its own gravity. Stage 2 - A region of condensing matter will begin to heat up and start to glow forming Protostars. If a protostar contains enough matter, the central temperature reaches 15 million degrees centigrade. Stage 3 - At this tempe ...
... into a huge globule of gas and dust which contracts under its own gravity. Stage 2 - A region of condensing matter will begin to heat up and start to glow forming Protostars. If a protostar contains enough matter, the central temperature reaches 15 million degrees centigrade. Stage 3 - At this tempe ...
Diapositiva 1 - Dipartimento di Fisica
... of the 113 stars examined so far. For most of these stars the temperatures can be found in the GAUDI archive: searching for some correlation between differential rotation and temperature, we spotted an excess of anti-solar differential rotation in stars with T ≥ 7900°K, i.e. without outer convective ...
... of the 113 stars examined so far. For most of these stars the temperatures can be found in the GAUDI archive: searching for some correlation between differential rotation and temperature, we spotted an excess of anti-solar differential rotation in stars with T ≥ 7900°K, i.e. without outer convective ...
PH607 – Galaxies 1
... regions, or is produced by energetic electrons moving in magnetic fields Near Infrared: Most of the emission at these wavelengths is from relatively cool giant K stars in the disk and bulge X-rays: extended soft X-ray emission is detected from hot, shocked gas. At the lower energies especially, the ...
... regions, or is produced by energetic electrons moving in magnetic fields Near Infrared: Most of the emission at these wavelengths is from relatively cool giant K stars in the disk and bulge X-rays: extended soft X-ray emission is detected from hot, shocked gas. At the lower energies especially, the ...
Transcript of this week`s podcast
... evenly distributed. As these atoms gravitated to each other, they formed denser clouds of gas that then became compact. As they compacted, the pressure at the centres of these masses caused temperature increases as high as 10 million degrees centigrade. At this temperature, hydrogen atoms were no lo ...
... evenly distributed. As these atoms gravitated to each other, they formed denser clouds of gas that then became compact. As they compacted, the pressure at the centres of these masses caused temperature increases as high as 10 million degrees centigrade. At this temperature, hydrogen atoms were no lo ...
Hubblecast Episode 64: It All Ends with a Bang! — The incineration of
... study distant supernovae to better understand the expansion of the cosmos. And Hubble plays a big part in this game. It just recently hit another milestone when it spotted the most distant supernova ...
... study distant supernovae to better understand the expansion of the cosmos. And Hubble plays a big part in this game. It just recently hit another milestone when it spotted the most distant supernova ...
the formation of the earth
... in the core increased, causing a nuclear fusion reaction: hydrogen atoms collided so violently that they fused together to form helium. The star glowed with a bright yellow light. It had become our sun. The rotation of the nebular cloud forming the sun caused it to assume a flattened disk shape. Wit ...
... in the core increased, causing a nuclear fusion reaction: hydrogen atoms collided so violently that they fused together to form helium. The star glowed with a bright yellow light. It had become our sun. The rotation of the nebular cloud forming the sun caused it to assume a flattened disk shape. Wit ...
NGC 3370 Spiral Galaxy - University of Kentucky
... F = Gm1m2/r2 where m1 and m2 are the masses of two objects and r is the distance between them. Here is a little thought experiment. What if the Sun were to collapse and form a black hole right now? Let’s suppose that all of the mass of the Sun falls into the black hole. So the mass doesn’t change at ...
... F = Gm1m2/r2 where m1 and m2 are the masses of two objects and r is the distance between them. Here is a little thought experiment. What if the Sun were to collapse and form a black hole right now? Let’s suppose that all of the mass of the Sun falls into the black hole. So the mass doesn’t change at ...
Römer and the speed of light
... Pogson (1856): A 1st magnitude star is 100 times brighter than a 6th magnitude star! The Eye is a negative logarithmic detector. ...
... Pogson (1856): A 1st magnitude star is 100 times brighter than a 6th magnitude star! The Eye is a negative logarithmic detector. ...
Cosmology - RHIG - Wayne State University
... total mass by the mass of a typical star (e.g., 1 solar mass). The result is about 200 billion stars! The actual number of stars could be several tens of billions less or more than this approximate value. ...
... total mass by the mass of a typical star (e.g., 1 solar mass). The result is about 200 billion stars! The actual number of stars could be several tens of billions less or more than this approximate value. ...
Animated Planets PowerPoint Presentation
... LT: Understand comet make-up, properties, Vocab.: 1. comet nucleus 2. Halley’s comet 3. “dirty snowball” Agenda: Comet Notes ...
... LT: Understand comet make-up, properties, Vocab.: 1. comet nucleus 2. Halley’s comet 3. “dirty snowball” Agenda: Comet Notes ...
Anna Frebel nucleosynthesis, stars + chemical evolution
... Halo Metallicity distribution function (MDF) ...
... Halo Metallicity distribution function (MDF) ...
Main sequence
In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell. Stars on this band are known as main-sequence stars or ""dwarf"" stars.After a star has formed, it generates thermal energy in the dense core region through the nuclear fusion of hydrogen atoms into helium. During this stage of the star's lifetime, it is located along the main sequence at a position determined primarily by its mass, but also based upon its chemical composition and other factors. All main-sequence stars are in hydrostatic equilibrium, where outward thermal pressure from the hot core is balanced by the inward pressure of gravitational collapse from the overlying layers. The strong dependence of the rate of energy generation in the core on the temperature and pressure helps to sustain this balance. Energy generated at the core makes its way to the surface and is radiated away at the photosphere. The energy is carried by either radiation or convection, with the latter occurring in regions with steeper temperature gradients, higher opacity or both.The main sequence is sometimes divided into upper and lower parts, based on the dominant process that a star uses to generate energy. Stars below about 1.5 times the mass of the Sun (or 1.5 solar masses (M☉)) primarily fuse hydrogen atoms together in a series of stages to form helium, a sequence called the proton–proton chain. Above this mass, in the upper main sequence, the nuclear fusion process mainly uses atoms of carbon, nitrogen and oxygen as intermediaries in the CNO cycle that produces helium from hydrogen atoms. Main-sequence stars with more than two solar masses undergo convection in their core regions, which acts to stir up the newly created helium and maintain the proportion of fuel needed for fusion to occur. Below this mass, stars have cores that are entirely radiative with convective zones near the surface. With decreasing stellar mass, the proportion of the star forming a convective envelope steadily increases, whereas main-sequence stars below 0.4 M☉ undergo convection throughout their mass. When core convection does not occur, a helium-rich core develops surrounded by an outer layer of hydrogen.In general, the more massive a star is, the shorter its lifespan on the main sequence. After the hydrogen fuel at the core has been consumed, the star evolves away from the main sequence on the HR diagram. The behavior of a star now depends on its mass, with stars below 0.23 M☉ becoming white dwarfs directly, whereas stars with up to ten solar masses pass through a red giant stage. More massive stars can explode as a supernova, or collapse directly into a black hole.