Astronomy Activity: The Life-Line of the Stars
... Just like a fire flame (like a burning match) has different colors, so do the stars. This is because stars have different temperatures. Really hot stars are blue or white-hot. Cool stars are red or redish-orange in color. Astronomers classify stars based on what they are made of (in addition to hydr ...
... Just like a fire flame (like a burning match) has different colors, so do the stars. This is because stars have different temperatures. Really hot stars are blue or white-hot. Cool stars are red or redish-orange in color. Astronomers classify stars based on what they are made of (in addition to hydr ...
Chapter 14
... As the planets orbit around the pulsar, they cause it to wobble around, resulting in slight changes of the observed pulsar period. ...
... As the planets orbit around the pulsar, they cause it to wobble around, resulting in slight changes of the observed pulsar period. ...
document
... Frequency: the number of wave cycles per unit of time that are registered at a given point in space. (referred to by Greek letter n [nu]) n is inversely proportional to wavelength ...
... Frequency: the number of wave cycles per unit of time that are registered at a given point in space. (referred to by Greek letter n [nu]) n is inversely proportional to wavelength ...
PowerPoint Presentation - Neutron stars, pulsars and black holes
... • The discovery of pulsars that were spinning more than 100 times per second (the first was spinning 640 times per second) threw the field for a loop. When some millisecond pulsars were discovered in old star clusters it was even more confusing. • Eventually it was determined that all millisecond pu ...
... • The discovery of pulsars that were spinning more than 100 times per second (the first was spinning 640 times per second) threw the field for a loop. When some millisecond pulsars were discovered in old star clusters it was even more confusing. • Eventually it was determined that all millisecond pu ...
“Missing” Local Group Satellites
... Star Formation in Extreme Dwarfs • Leo T: a unique (?) laboratory – a very low mass, relatively isolated system with gas and recent star formation • Hα (Gemini) and UV (pointed GALEX + Swift/UVOT) observations to study recent star formation: no detected H II regions no ongoing SF… or no O st ...
... Star Formation in Extreme Dwarfs • Leo T: a unique (?) laboratory – a very low mass, relatively isolated system with gas and recent star formation • Hα (Gemini) and UV (pointed GALEX + Swift/UVOT) observations to study recent star formation: no detected H II regions no ongoing SF… or no O st ...
The Sun and the Stars
... When we looks at young clusters and globular clusters their colour-magnitude diagrams appear very different Globular clusters consist of ~half a million stars gravitationally bound, and located above the plane of the galaxy. They are old metal poor stars. Show extensive red-giant,AGB and horizontal ...
... When we looks at young clusters and globular clusters their colour-magnitude diagrams appear very different Globular clusters consist of ~half a million stars gravitationally bound, and located above the plane of the galaxy. They are old metal poor stars. Show extensive red-giant,AGB and horizontal ...
Stellar Physics - Craigie High School
... Now consider what happens when a photon is emitted from the surface of a star of radius r and mass M. The energy of the photon, hf, decreases as it travels to positions of greater gravitational potential energy but the velocity of the photon remains the same. Observers at different heights will obse ...
... Now consider what happens when a photon is emitted from the surface of a star of radius r and mass M. The energy of the photon, hf, decreases as it travels to positions of greater gravitational potential energy but the velocity of the photon remains the same. Observers at different heights will obse ...
stellar spectra instructor notes
... in the hot, gaseous atmospheres that constitute the outermost thin layers of all stars. Visible light penetrates not very deeply into stellar atmospheres, but goes deep enough to pass through the cool surface layers at the top of the atmospheres into deeper regions where the local temperatures are u ...
... in the hot, gaseous atmospheres that constitute the outermost thin layers of all stars. Visible light penetrates not very deeply into stellar atmospheres, but goes deep enough to pass through the cool surface layers at the top of the atmospheres into deeper regions where the local temperatures are u ...
Can you write numbers in scientific notation
... Can you convert measurements in the metric system to other units within the metric system? How about converting between the metric and British systems? Matter/Light Properties Can you describe the structure of an atom? Do you know what makes one element different from another? What is an isotope? Wh ...
... Can you convert measurements in the metric system to other units within the metric system? How about converting between the metric and British systems? Matter/Light Properties Can you describe the structure of an atom? Do you know what makes one element different from another? What is an isotope? Wh ...
ppt
... depth of about t l = 2/3 as measured straight back along the line of sight Photon’s at a distance of less than 1 mean free path from the surface are likely to escape Star’s photosphere is defined to be the layer from which visible light originates Formation of spectral lines (absorption) occur becau ...
... depth of about t l = 2/3 as measured straight back along the line of sight Photon’s at a distance of less than 1 mean free path from the surface are likely to escape Star’s photosphere is defined to be the layer from which visible light originates Formation of spectral lines (absorption) occur becau ...
AN INTRODUCTION TO ASTRONOMY Dr. Uri Griv •
... Explanation: How could a galaxy become shaped like a ring? The rim of the blue galaxy pictured on the right is an immense ring-like structure 150,000 light years in diameter composed of newly formed, extremely bright, massive stars. That galaxy, AM 0644-741, is known as a ring galaxy and was caused ...
... Explanation: How could a galaxy become shaped like a ring? The rim of the blue galaxy pictured on the right is an immense ring-like structure 150,000 light years in diameter composed of newly formed, extremely bright, massive stars. That galaxy, AM 0644-741, is known as a ring galaxy and was caused ...
Properties of Supernovae
... is thought to be a Population II white dwarf in a binary system with a red giant companion. Mass from the red giant accretes onto the white dwarf until the dwarf's mass passes the Chandresekhar limit of 1.4 solar masses. The dwarf then collapses violently and becomes a Type I supernova. The progenit ...
... is thought to be a Population II white dwarf in a binary system with a red giant companion. Mass from the red giant accretes onto the white dwarf until the dwarf's mass passes the Chandresekhar limit of 1.4 solar masses. The dwarf then collapses violently and becomes a Type I supernova. The progenit ...
30.4 Gravitational collapse & early protostellar evolution I (HB)
... not given anymore. - Convection begins because deuterium fusion produces too much energy to be transported radiatively through opaque interior. Since ∂s/∂Mr < 0 parcels are underdense ((rint)1 < (rext)1) and hot. After transfering excess heat to surrounding medium, denser/cooler parcels travel downw ...
... not given anymore. - Convection begins because deuterium fusion produces too much energy to be transported radiatively through opaque interior. Since ∂s/∂Mr < 0 parcels are underdense ((rint)1 < (rext)1) and hot. After transfering excess heat to surrounding medium, denser/cooler parcels travel downw ...
Dynamic
... This conclusion is valid for all unstable equations of state, namely, for adiabatic with γ < 4/3. In reality a presence of dissipation leads to damping of these oscillations, and to final collapse of nonrotating model, when total energy of the body is negative. ...
... This conclusion is valid for all unstable equations of state, namely, for adiabatic with γ < 4/3. In reality a presence of dissipation leads to damping of these oscillations, and to final collapse of nonrotating model, when total energy of the body is negative. ...
Surveying the Stars
... • What is the significance of the main sequence? — Normal stars that fuse H to He in their cores fall on the main sequence of an H-R diagram. — A star’s mass determines its position along the main sequence (high mass: luminous and blue; low mass: faint and red). ...
... • What is the significance of the main sequence? — Normal stars that fuse H to He in their cores fall on the main sequence of an H-R diagram. — A star’s mass determines its position along the main sequence (high mass: luminous and blue; low mass: faint and red). ...
A prevalence of dynamo-generated magnetic fields in the
... for magnetic buoyancy mixing26 is similar to the field strength required for dipole mode suppression8. After some time, intermediate-mass red giants also start burning helium in their cores. Suppressed dipolar modes in those so-called red clump stars will reveal whether the fields survive until heli ...
... for magnetic buoyancy mixing26 is similar to the field strength required for dipole mode suppression8. After some time, intermediate-mass red giants also start burning helium in their cores. Suppressed dipolar modes in those so-called red clump stars will reveal whether the fields survive until heli ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.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.