Lecture 9: Stellar Spectra
... Most of the H is ionized, so only very weak H lines in visible A Stars (7500-11,000K) Ideal excitation conditions, strongest H lines in visible. G stars (5200-5900 K) Too cool, little excited H, so only weak H lines in the visible Line strengths diagram shown in Figure 19-12 ...
... Most of the H is ionized, so only very weak H lines in visible A Stars (7500-11,000K) Ideal excitation conditions, strongest H lines in visible. G stars (5200-5900 K) Too cool, little excited H, so only weak H lines in the visible Line strengths diagram shown in Figure 19-12 ...
Today in Astronomy 142: observations of stars
... ! RA (right ascension) tells you when your object is up. • 12 hours is up highest Mar 21 • 0 hours is up highest Sept 21 ! DEC (declination) tells you how far away from the north pole. Polaris is at +90. Anything below 0 degrees is hard to observe from the northern hemisphere. ! Spectral types and ...
... ! RA (right ascension) tells you when your object is up. • 12 hours is up highest Mar 21 • 0 hours is up highest Sept 21 ! DEC (declination) tells you how far away from the north pole. Polaris is at +90. Anything below 0 degrees is hard to observe from the northern hemisphere. ! Spectral types and ...
magnitude handout
... How do we use this table? The magnitude difference between two stars along with Table 2 gives us the brightness ratio, how many times brighter the star is. We can also work the other way. Thus if star A is 40 times brighter than star B, the table tells us that A is 4 magnitudes brighter. It is prett ...
... How do we use this table? The magnitude difference between two stars along with Table 2 gives us the brightness ratio, how many times brighter the star is. We can also work the other way. Thus if star A is 40 times brighter than star B, the table tells us that A is 4 magnitudes brighter. It is prett ...
Nebulae - Innovative Teachers BG
... are stellar clusters. The Galactic Stellar Clusters have a relatively small number (a few hundreds) of bright hot stars. These astronomical objects are observed in the spirals of the galactic plane and are realtively young – hundred millions years. Oposite to them are Globular Clusters found as a ru ...
... are stellar clusters. The Galactic Stellar Clusters have a relatively small number (a few hundreds) of bright hot stars. These astronomical objects are observed in the spirals of the galactic plane and are realtively young – hundred millions years. Oposite to them are Globular Clusters found as a ru ...
Star Formation: Interstellar Gas and Dust
... Example: The Orion Nebula • 1500 LY away from us • The central “star” in Orion’s sword. Ionizing O star ...
... Example: The Orion Nebula • 1500 LY away from us • The central “star” in Orion’s sword. Ionizing O star ...
Nebular theory
... The Nebular Theory – How did our Solar System form? Our theory about how the solar system formed is called the nebular theory. This activity will help you understand how we think the solar system formed. 1. Write your observations from the video that shows how the planets orbit the sun. Write at lea ...
... The Nebular Theory – How did our Solar System form? Our theory about how the solar system formed is called the nebular theory. This activity will help you understand how we think the solar system formed. 1. Write your observations from the video that shows how the planets orbit the sun. Write at lea ...
Milky Way - Wayne Hu`s Tutorials
... • Extinction also depends on direction, e.g. through the disk, through a giant molecular cloud, etc. Typical value at visible wavelengths and in the disk is 1 mag/kpc • Dust emits or reradiates starlight in the infrared - maps from these frequencies [IRAS, DIRBE] can be used to calibrate extinction ...
... • Extinction also depends on direction, e.g. through the disk, through a giant molecular cloud, etc. Typical value at visible wavelengths and in the disk is 1 mag/kpc • Dust emits or reradiates starlight in the infrared - maps from these frequencies [IRAS, DIRBE] can be used to calibrate extinction ...
Measuring the Distances to the Stars: Parallax What sets the parallax limit?
... Hipparcos (1989-1993): 100-200 parsecs (1σ =1 milliarcsec = 1kpc) ...
... Hipparcos (1989-1993): 100-200 parsecs (1σ =1 milliarcsec = 1kpc) ...
Introduction to the HR Diagram
... in the lower right corner called red dwarfs. The more massive the star, the faster the rate of fusion, and the less time is remains on the main sequence. The amount of time that a star spends on the main sequence is also a function of its mass and luminosity and is defined as: T(years) = 1010M. L Th ...
... in the lower right corner called red dwarfs. The more massive the star, the faster the rate of fusion, and the less time is remains on the main sequence. The amount of time that a star spends on the main sequence is also a function of its mass and luminosity and is defined as: T(years) = 1010M. L Th ...
Star Formation
... • Models show that Sun required about 30 million years to go from protostar to main sequence • Higher-mass stars form faster • Lower-mass stars form more slowly ...
... • Models show that Sun required about 30 million years to go from protostar to main sequence • Higher-mass stars form faster • Lower-mass stars form more slowly ...
Other Galaxies, their Distances, and the Expansion of the Universe
... Some galaxies even show evidence for very violent ejection of material into the intergalactic space ...
... Some galaxies even show evidence for very violent ejection of material into the intergalactic space ...
H-R Diagram
... (2) 3.Using a circled dot , graph each of the brightest stars as seen from Earth (listed in Figure 21.2) on the diagram. Show stars that appear on both tables using a circled plus sign ...
... (2) 3.Using a circled dot , graph each of the brightest stars as seen from Earth (listed in Figure 21.2) on the diagram. Show stars that appear on both tables using a circled plus sign ...
Photoelectric Photometry of the Pleiades Student Manual
... The computer program you will use is a realistic simulation of a UBV photometer attached to a moderate sized research telescope. The telescope is controlled by a computer that allows you to move from star to star and make measurements. Different filters can be selected for each observation, and the ...
... The computer program you will use is a realistic simulation of a UBV photometer attached to a moderate sized research telescope. The telescope is controlled by a computer that allows you to move from star to star and make measurements. Different filters can be selected for each observation, and the ...
The Hertzsprung-Russell Diagram
... 9. Label the following steps on your H-R diagram to show the series of changes that our sun has undergone since its formation 4.6 billion years ago. a. Originally, a big cloud of gas and dust called a nebula condensed to form a young, cool star called a red dwarf. In this first stage of life, our s ...
... 9. Label the following steps on your H-R diagram to show the series of changes that our sun has undergone since its formation 4.6 billion years ago. a. Originally, a big cloud of gas and dust called a nebula condensed to form a young, cool star called a red dwarf. In this first stage of life, our s ...
The Birth of Stars Guiding Questions • Because stars shine by
... are glowing, ionized clouds of gas – Emission nebulae are powered by ultraviolet light that they absorb from nearby hot stars ...
... are glowing, ionized clouds of gas – Emission nebulae are powered by ultraviolet light that they absorb from nearby hot stars ...
The Birth of Stars
... are glowing, ionized clouds of gas – Emission nebulae are powered by ultraviolet light that they absorb from nearby hot stars ...
... are glowing, ionized clouds of gas – Emission nebulae are powered by ultraviolet light that they absorb from nearby hot stars ...
Student Worksheet - Indiana University Astronomy
... energy is needed to describe the brightness of astronomical sources because, being at very large distances, the stars appear to be extremely faint. The graph labeled "Flux Densities for IC 4665" displays the expected brightness of stars of different temperatures at a distance of 352 parsecs, the dis ...
... energy is needed to describe the brightness of astronomical sources because, being at very large distances, the stars appear to be extremely faint. The graph labeled "Flux Densities for IC 4665" displays the expected brightness of stars of different temperatures at a distance of 352 parsecs, the dis ...
Be Stars
... Finally, there are Be stars that show a prominent emission spectrum of hydrogen this is because they have a rapid rate of rotation, with an equatorial rotation velocity of about 200km/s, which in relation to the suns rotation of about 2 km/s is very fast ...
... Finally, there are Be stars that show a prominent emission spectrum of hydrogen this is because they have a rapid rate of rotation, with an equatorial rotation velocity of about 200km/s, which in relation to the suns rotation of about 2 km/s is very fast ...
Lecture 5: Stars
... We find that stars range in mass from about 10-2M to about 102M. (Technically ‘stars’ less than about 0.1M are ‘brown dwarfs’ not stars as they do not burn H.) About 90% of stars lie on the main sequence (as we’ll see this is where they spend most of their lives burning H in their cores). The ‘’ ...
... We find that stars range in mass from about 10-2M to about 102M. (Technically ‘stars’ less than about 0.1M are ‘brown dwarfs’ not stars as they do not burn H.) About 90% of stars lie on the main sequence (as we’ll see this is where they spend most of their lives burning H in their cores). The ‘’ ...
Astronomy – The Milky Way Galaxy
... – This is called cosmological _______________. – Proven by observing a faint glow of __________________ that is a remnant of _________ from the Big Bang. – Early Universe = __________ and ____________ – Today’s Universe = __________ and ________ ___________ because of ...
... – This is called cosmological _______________. – Proven by observing a faint glow of __________________ that is a remnant of _________ from the Big Bang. – Early Universe = __________ and ____________ – Today’s Universe = __________ and ________ ___________ because of ...
Lecture17
... How can this be? They emit less light per square meter than a blue main sequence star, but, they are much, much bigger (more square meters)! ...
... How can this be? They emit less light per square meter than a blue main sequence star, but, they are much, much bigger (more square meters)! ...
Cluster and Association Members
... are physically related groups of stars held together by mutual gravitational attraction. Therefore, they populate a limited region of space, which is typically much smaller than their distance from the Sun, so that the members are all approximately at the same distance. They are believed to originat ...
... are physically related groups of stars held together by mutual gravitational attraction. Therefore, they populate a limited region of space, which is typically much smaller than their distance from the Sun, so that the members are all approximately at the same distance. They are believed to originat ...
Corona Australis
Corona Australis /kɵˈroʊnə ɒˈstreɪlɨs/ or Corona Austrina /kɵˈroʊnə ɒˈstraɪnə/ is a constellation in the Southern Celestial Hemisphere. Its Latin name means ""southern crown"", and it is the southern counterpart of Corona Borealis, the northern crown. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations. The Ancient Greeks saw Corona Australis as a wreath rather than a crown and associated it with Sagittarius or Centaurus. Other cultures have likened the pattern to a turtle, ostrich nest, a tent, or even a hut belonging to a rock hyrax.Although fainter than its namesake, the oval- or horseshoe-shaped pattern of its brighter stars renders it distinctive. Alpha and Beta Coronae Australis are the two brightest stars with an apparent magnitude of around 4.1. Epsilon Coronae Australis is the brightest example of a W Ursae Majoris variable in the southern sky. Lying alongside the Milky Way, Corona Australis contains one of the closest star-forming regions to our Solar System—a dusty dark nebula known as the Corona Australis Molecular Cloud, lying about 430 light years away. Within it are stars at the earliest stages of their lifespan. The variable stars R and TY Coronae Australis light up parts of the nebula, which varies in brightness accordingly.