![Galaxies and the Universe](http://s1.studyres.com/store/data/014353600_1-fda003f73248c6b01ebf14e0bc30dfed-300x300.png)
Galaxies and the Universe
... • You can get the distance to something if you know how much light we receive at Earth (the flux), and how much light it actually gives off (the luminosity). • Standard candles are objects where some observed property allows one to infer the luminosity. • Two examples: – Variable stars: stars that h ...
... • You can get the distance to something if you know how much light we receive at Earth (the flux), and how much light it actually gives off (the luminosity). • Standard candles are objects where some observed property allows one to infer the luminosity. • Two examples: – Variable stars: stars that h ...
luminosity1
... • Spectral typing can be used to find the surface temperature of a star. (Along with color and Wien’s Law) • Spectral typing can also be used to find out how much of a given element is in a star. • HD 161817 has much less of all the elements, other than Hydrogen and Helium, than the Sun. • In fact, ...
... • Spectral typing can be used to find the surface temperature of a star. (Along with color and Wien’s Law) • Spectral typing can also be used to find out how much of a given element is in a star. • HD 161817 has much less of all the elements, other than Hydrogen and Helium, than the Sun. • In fact, ...
A little bit more to do. Stefan
... • Spectral typing can be used to find the surface temperature of a star. (Along with color and Wien’s Law) • Spectral typing can also be used to find out how much of a given element is in a star. • HD 161817 has much less of all the elements, other than Hydrogen and Helium, than the Sun. • In fact, ...
... • Spectral typing can be used to find the surface temperature of a star. (Along with color and Wien’s Law) • Spectral typing can also be used to find out how much of a given element is in a star. • HD 161817 has much less of all the elements, other than Hydrogen and Helium, than the Sun. • In fact, ...
Characterizing Stars - Department of Physics and Astronomy
... • Parallax measurements made from orbit, above the blurring effects of the atmosphere, are much more accurate than those made with Earth-based telescopes • Stellar parallaxes can only be measured for stars within a few hundred parsecs ...
... • Parallax measurements made from orbit, above the blurring effects of the atmosphere, are much more accurate than those made with Earth-based telescopes • Stellar parallaxes can only be measured for stars within a few hundred parsecs ...
Here
... • Here is the “Big Dipper”, which is not an “official” constellation but part of a larger one. • Again, the stars are usually not physically associated with each other. ...
... • Here is the “Big Dipper”, which is not an “official” constellation but part of a larger one. • Again, the stars are usually not physically associated with each other. ...
Tour the sky`s reddest stars
... of stars by their spectral types, was so impressed with Y CVn that he called it “La Superba.” Scientists study a star’s spectrum by measuring the intensity of its light at different wavelengths. The standard spectral classes assign letters to stars based on their temperatures. From hottest to cooles ...
... of stars by their spectral types, was so impressed with Y CVn that he called it “La Superba.” Scientists study a star’s spectrum by measuring the intensity of its light at different wavelengths. The standard spectral classes assign letters to stars based on their temperatures. From hottest to cooles ...
Candles in the Dark
... and is in fact iuseless for measuring distances of more than about 1600 light years. How then can we tell, for example, that M31, the galaxy in Andromeda, is 2.2 million light years away? It would be straight-forward to tell how far away a star was if it was exactly the same brightness as our own Su ...
... and is in fact iuseless for measuring distances of more than about 1600 light years. How then can we tell, for example, that M31, the galaxy in Andromeda, is 2.2 million light years away? It would be straight-forward to tell how far away a star was if it was exactly the same brightness as our own Su ...
Life in the Universe - University of Georgia
... Angle, distance, and Powers of Ten Lecture 2 by Inseok Song ...
... Angle, distance, and Powers of Ten Lecture 2 by Inseok Song ...
Movements of Objects in Space
... 2. The Moon is orbiting around the Earth [one orbit every 27.3 days]. ...
... 2. The Moon is orbiting around the Earth [one orbit every 27.3 days]. ...
Sizing Up The Universe
... distant galaxies, the angular size of the galaxy. Hubble then measured the radial velocities of these galaxies using the redshifts he found in their spectral lines. Galaxies showing a redshift are moving away from us. On average, Hubble found, the larger their distance, the larger their redshift. So ...
... distant galaxies, the angular size of the galaxy. Hubble then measured the radial velocities of these galaxies using the redshifts he found in their spectral lines. Galaxies showing a redshift are moving away from us. On average, Hubble found, the larger their distance, the larger their redshift. So ...
galaxy.
... • van Maanen’s observations showed that one spiral nebula, M 101, could be observed to rotate. It it were outside our galaxy, it would have to be turning faster than the speed of light. • Spiral nebulae were never seen in the Milky Way: the “zone of avoidance.” Therefore, their distribution acknowle ...
... • van Maanen’s observations showed that one spiral nebula, M 101, could be observed to rotate. It it were outside our galaxy, it would have to be turning faster than the speed of light. • Spiral nebulae were never seen in the Milky Way: the “zone of avoidance.” Therefore, their distribution acknowle ...
h-r_diagram_online_lab
... The original H-R diagram plotted the star’s luminosity versus its spectral type. It only included stars within 100 pc of the Sun as that was the limit for determining distances using the heliocentric parallax method, the only known method at the time. ...
... The original H-R diagram plotted the star’s luminosity versus its spectral type. It only included stars within 100 pc of the Sun as that was the limit for determining distances using the heliocentric parallax method, the only known method at the time. ...
The HR Diagram (PowerPoint version)
... The stars do not differ significantly in composition! They are ~ 2/3 H, ~ 1/3 He, with just a few percent of everything else (at least in the outer parts, which is what the spectrum tells us about) Incidentally, helium was first detected in the solar spectrum (hence its name, from the Greek ‘helios’ ...
... The stars do not differ significantly in composition! They are ~ 2/3 H, ~ 1/3 He, with just a few percent of everything else (at least in the outer parts, which is what the spectrum tells us about) Incidentally, helium was first detected in the solar spectrum (hence its name, from the Greek ‘helios’ ...
Stellar Spectral Classes
... Using these data, describe and explain one similarity and one difference in the appearance of the two stars as seen with the unaided eye by an observer on the Earth. similarity................................................................................................. ...
... Using these data, describe and explain one similarity and one difference in the appearance of the two stars as seen with the unaided eye by an observer on the Earth. similarity................................................................................................. ...
Cluster and Association Members
... 2005). Extensive grids of stellar tracks covering the most important evolutionary phases and a large metallicity range are available. This method is based on the knowledge of all members of the cluster making it statistically significant. Recently, Paunzen & Netopil (2006) have summarized our current ...
... 2005). Extensive grids of stellar tracks covering the most important evolutionary phases and a large metallicity range are available. This method is based on the knowledge of all members of the cluster making it statistically significant. Recently, Paunzen & Netopil (2006) have summarized our current ...
Study Guide Ch10,11 and 12
... 8. Be able to identify a galaxy by its shape, according to the Hubble sequence. 9. Compare and contrast elliptical galaxies and spiral galaxies. 10. Describe the different types of active galaxies, and the mechanisms proposed to explain their energy output and other characteristics. 11. Briefly rela ...
... 8. Be able to identify a galaxy by its shape, according to the Hubble sequence. 9. Compare and contrast elliptical galaxies and spiral galaxies. 10. Describe the different types of active galaxies, and the mechanisms proposed to explain their energy output and other characteristics. 11. Briefly rela ...
Characteristics of Stars (Ph)
... Characteristics of Stars Imagine you could travel to the stars at the speed of light. To travel from Earth to the sun would take about 8 minutes, not very long for such a long trip! Yet the next nearest star, Proxima Centauri, is much farther away—a trip to Proxima Centauri would take 4.2 years! ...
... Characteristics of Stars Imagine you could travel to the stars at the speed of light. To travel from Earth to the sun would take about 8 minutes, not very long for such a long trip! Yet the next nearest star, Proxima Centauri, is much farther away—a trip to Proxima Centauri would take 4.2 years! ...
What`s a Parsec? - The Sky This Week
... The speed of light in terms you may be more familiar with is 186,282.4 miles per second, or a whopping 671 million miles per hour. Even so, the nearest known star beyond our solar system, Proxima Centauri, is 4.23 ± 0.01 ly away. In a year, then, light travels 9.5 trillion kilometers, which is 5.9 t ...
... The speed of light in terms you may be more familiar with is 186,282.4 miles per second, or a whopping 671 million miles per hour. Even so, the nearest known star beyond our solar system, Proxima Centauri, is 4.23 ± 0.01 ly away. In a year, then, light travels 9.5 trillion kilometers, which is 5.9 t ...
The Sun - Center for Astrophysics and Space Astronomy
... • How many times more energy is there in an x-ray photon at 100A than the infrared light photons emitted by every living human? (Assuming 10,000nm wavelength of infrared light). • A. Ten times as powerful. • B. A hundred times more powerful. • C. A thousand times more powerful. • D. 1x1012 (a trilli ...
... • How many times more energy is there in an x-ray photon at 100A than the infrared light photons emitted by every living human? (Assuming 10,000nm wavelength of infrared light). • A. Ten times as powerful. • B. A hundred times more powerful. • C. A thousand times more powerful. • D. 1x1012 (a trilli ...
14.5 Yellow Giants and Pulsating Stars Variable Stars Not all stars
... radius star has a weaker surface gravity than a smallradius star. Hence, gravity pulls more feebly inward for a largeradius star than for a smallradius one, so its pulsation takes longer. As a result, big (and therefore bright) stars pulsate more slowly than small (and therefore dim) stars. The p ...
... radius star has a weaker surface gravity than a smallradius star. Hence, gravity pulls more feebly inward for a largeradius star than for a smallradius one, so its pulsation takes longer. As a result, big (and therefore bright) stars pulsate more slowly than small (and therefore dim) stars. The p ...
Chapter 8 - TeacherWeb
... Stars can be classified by their size, mass, brightness, color, temperature, spectrum, and age. Can also be classified as main-sequence stars, giants, supergiants, and white dwarfs. Can be reclassified later in its life. http://didyouknow.org/the-size-of-the-sun-in-comparison/ ...
... Stars can be classified by their size, mass, brightness, color, temperature, spectrum, and age. Can also be classified as main-sequence stars, giants, supergiants, and white dwarfs. Can be reclassified later in its life. http://didyouknow.org/the-size-of-the-sun-in-comparison/ ...
Star`s ReadingStar`s Reading(es)
... Apparent Magnitude A star’s apparent magnitude is its brightness as seen from Earth. Astronomers can measure apparent magnitude fairly easily using electronic devices. Astronomers cannot tell how much light a star gives off just from the star’s apparent magnitude. Just as a flashlight looks brighte ...
... Apparent Magnitude A star’s apparent magnitude is its brightness as seen from Earth. Astronomers can measure apparent magnitude fairly easily using electronic devices. Astronomers cannot tell how much light a star gives off just from the star’s apparent magnitude. Just as a flashlight looks brighte ...
Sample Exam 3
... 24) The Hubble Space Telescope has been used to observe supernova type Ia in distant galaxies, to measure the distance using the brightness law—independent of the velocity redshift distance. The last supernova Ia in the Milky Way happened about 400 years ago, but many type Ia’s have been observed by ...
... 24) The Hubble Space Telescope has been used to observe supernova type Ia in distant galaxies, to measure the distance using the brightness law—independent of the velocity redshift distance. The last supernova Ia in the Milky Way happened about 400 years ago, but many type Ia’s have been observed by ...
Malmquist bias
The Malmquist bias is an effect in observational astronomy which leads to the preferential detection of intrinsically bright objects. It was first described in 1922 by Swedish astronomer Gunnar Malmquist (1893–1982), who then greatly elaborated upon this work in 1925. In statistics, this bias is referred to as a selection bias and affects the survey results in a brightness limited survey, where stars below a certain apparent brightness are not included. Since observed stars and galaxies appear dimmer when farther away, the brightness that is measured will fall off with distance until their brightness falls below the observational threshold. Objects which are more luminous, or intrinsically brighter, can be observed at a greater distance, creating a false trend of increasing intrinsic brightness, and other related quantities, with distance. This effect has led to many spurious claims in the field of astronomy. Properly correcting for these effects has become an area of great focus.