The measure of Cosmological distances
... 1917: Shapley & Hertzsprung measured the distance to a Cepheid allow the use of Cepheids as “Standard candles” 1918: Harlow Shapely measures the milky way ...
... 1917: Shapley & Hertzsprung measured the distance to a Cepheid allow the use of Cepheids as “Standard candles” 1918: Harlow Shapely measures the milky way ...
Document
... These parameters can be measured directly using: • nearby/bright stars, (spectrum = composition) • binary stars, (binary orbit/separation = mass) • variable stars, (variation time + velocity = size) • clusters of stars. (i.e., at the same distance = coeval age) In general, the distance introduces th ...
... These parameters can be measured directly using: • nearby/bright stars, (spectrum = composition) • binary stars, (binary orbit/separation = mass) • variable stars, (variation time + velocity = size) • clusters of stars. (i.e., at the same distance = coeval age) In general, the distance introduces th ...
Exploring Space
... Star Birth When the core of the Protostar reaches 10 million K, pressure is so great that nuclear fusion occurs- a star is born Heat from fusion of hydrogen is released When balance is maintained from inward pressure (gravity) and outward pressure (heat) the Main-Sequence stage is ...
... Star Birth When the core of the Protostar reaches 10 million K, pressure is so great that nuclear fusion occurs- a star is born Heat from fusion of hydrogen is released When balance is maintained from inward pressure (gravity) and outward pressure (heat) the Main-Sequence stage is ...
lecture25
... We find mostly hot, massive stars in the spiral arms of galaxies because 1) hot, massive stars are preferentially produced in the spiral arms 2) less massive stars live long enough to rotate out of the spiral arms 3) supernovae destroy the less massive stars in the spiral arms 4) there is too high a ...
... We find mostly hot, massive stars in the spiral arms of galaxies because 1) hot, massive stars are preferentially produced in the spiral arms 2) less massive stars live long enough to rotate out of the spiral arms 3) supernovae destroy the less massive stars in the spiral arms 4) there is too high a ...
October 2013
... unremarkable to the eye, but one component of this 'double star' is a massive object which ejects material so vigorously that it has blasted out a 'bubble' more than three hundred light years across in the surrounding interstellar material. Part of the 'Coalsack', a remarkable dark cloud of dust blo ...
... unremarkable to the eye, but one component of this 'double star' is a massive object which ejects material so vigorously that it has blasted out a 'bubble' more than three hundred light years across in the surrounding interstellar material. Part of the 'Coalsack', a remarkable dark cloud of dust blo ...
REVIEW: STAR`S TEST
... What looks like a potato, orbits the sun between Mars and Jupiter, and is made of rock ? ______asteroid_______________ A rock that hits the Earth’s surface is called a ______meteorite______. A rock that is flying through space is called a _________meteoroid________. A rock that burns up in our atmos ...
... What looks like a potato, orbits the sun between Mars and Jupiter, and is made of rock ? ______asteroid_______________ A rock that hits the Earth’s surface is called a ______meteorite______. A rock that is flying through space is called a _________meteoroid________. A rock that burns up in our atmos ...
PH109 Exploring the Uiverse, Test #4, Spring, 1999
... a) young star clusters, b) O and B stars, c) globular clusters, d) emission nebulae 33. How long does it takes the Sun to travel around the center of the Galaxy a) one billion years, b) 250 million years, c) one million years, d) 5 billion years 34. Galaxies which show no flat structural feature, bu ...
... a) young star clusters, b) O and B stars, c) globular clusters, d) emission nebulae 33. How long does it takes the Sun to travel around the center of the Galaxy a) one billion years, b) 250 million years, c) one million years, d) 5 billion years 34. Galaxies which show no flat structural feature, bu ...
Stars
... Life span of a star depends on its size and mass. – Very large, massive stars burn their fuel much faster than smaller stars – Their main sequence may last only a few hundred thousand years – Smaller stars will live on for billions of years because they burn their fuel much more slowly ...
... Life span of a star depends on its size and mass. – Very large, massive stars burn their fuel much faster than smaller stars – Their main sequence may last only a few hundred thousand years – Smaller stars will live on for billions of years because they burn their fuel much more slowly ...
File - Etna FFA Agriculture
... A meteor is a bright streak of light that appears briefly in the sky. Observers often call meteors shooting stars or falling stars because they look like stars falling from the sky. A meteor appears when a particle or chunk of metallic or stony matter called a meteoroid enters the earth's atmosphere ...
... A meteor is a bright streak of light that appears briefly in the sky. Observers often call meteors shooting stars or falling stars because they look like stars falling from the sky. A meteor appears when a particle or chunk of metallic or stony matter called a meteoroid enters the earth's atmosphere ...
chapter 17 measuring the stars
... Luminosity is an intrinsic property of a star – it does not depend in any way on the location or motion of the observer – it is sometimes referred to as the star’s absolute brightness. Absolute Brightness: How bright a star would appear if it were placed at a standard distance of 10 parsecs from E ...
... Luminosity is an intrinsic property of a star – it does not depend in any way on the location or motion of the observer – it is sometimes referred to as the star’s absolute brightness. Absolute Brightness: How bright a star would appear if it were placed at a standard distance of 10 parsecs from E ...
chapter-30-pp
... slightly toward blue. This is called a “blue shift”. This is caused by shorter light waves as it moves toward Earth. ...
... slightly toward blue. This is called a “blue shift”. This is caused by shorter light waves as it moves toward Earth. ...
Astronomy - SchoolNotes
... of moving objects. Laid groundwork for the study of gravity by demonstrating the weight of an object does not affect its rate of fall. Discovered four moons of Jupiter Observed and recorded the phases of Venus ...
... of moving objects. Laid groundwork for the study of gravity by demonstrating the weight of an object does not affect its rate of fall. Discovered four moons of Jupiter Observed and recorded the phases of Venus ...
MilkyWay
... •Tried to estimate scattering due to ISM gas but determined it to be insignificant (most obscuration is due to dust absorption which has a smaller wavelength dependence) •Shapley (1919) observed that globular clusters are distributed asymmetrically in the sky and that if one assumes they are distrib ...
... •Tried to estimate scattering due to ISM gas but determined it to be insignificant (most obscuration is due to dust absorption which has a smaller wavelength dependence) •Shapley (1919) observed that globular clusters are distributed asymmetrically in the sky and that if one assumes they are distrib ...
ASTR 300 Stars and Stellar Systems Spring 2011
... 2. The parallax of the bright star Vega is 0.129 seconds of arc. What is the distance of Vega in parsecs ? In light-years ? We have the relation d(pc) = 1/p(arcsec) so the distance to Vega is d = 1/0.129 = 7.752 parsecs. One parsec = 3.26 light-years, so d = 3.26 × 7.753 = 25.3 ly. By how much, duri ...
... 2. The parallax of the bright star Vega is 0.129 seconds of arc. What is the distance of Vega in parsecs ? In light-years ? We have the relation d(pc) = 1/p(arcsec) so the distance to Vega is d = 1/0.129 = 7.752 parsecs. One parsec = 3.26 light-years, so d = 3.26 × 7.753 = 25.3 ly. By how much, duri ...
ASTR2050 Spring 2005 •
... • Composite spectrum binary: Two stellar spectra • Eclipsing binary: Information from “light curves” • Astrometric binary: Watch a “single” star wobble • Spectrographic binary: Doppler shifted spectrum ...
... • Composite spectrum binary: Two stellar spectra • Eclipsing binary: Information from “light curves” • Astrometric binary: Watch a “single” star wobble • Spectrographic binary: Doppler shifted spectrum ...
ASTRONOMY 313
... hydrogen at 1215 Å (corresponding to a transition between the first and second energy levels of neutral hydrogen atoms) is observed in the optical spectrum of HS1946+7658 to be in emission at a wavelength of 4884.3 Å, in the blue-green region. a. ...
... hydrogen at 1215 Å (corresponding to a transition between the first and second energy levels of neutral hydrogen atoms) is observed in the optical spectrum of HS1946+7658 to be in emission at a wavelength of 4884.3 Å, in the blue-green region. a. ...
Stellar kinematics
Stellar kinematics is the study of the movement of stars without needing to understand how they acquired their motion. This differs from stellar dynamics, which takes into account gravitational effects. The motion of a star relative to the Sun can provide useful information about the origin and age of a star, as well as the structure and evolution of the surrounding part of the Milky Way.In astronomy, it is widely accepted that most stars are born within molecular clouds known as stellar nurseries. The stars formed within such a cloud compose open clusters containing dozens to thousands of members. These clusters dissociate over time. Stars that separate themselves from the cluster's core are designated as members of the cluster's stellar association. If the remnant later drifts through the Milky Way as a coherent assemblage, then it is termed a moving group.