AN INTRODUCTION TO ASTRONOMY Dr. Uri Griv Department of Physics, Ben-Gurion University
... • The responce of the human eye works on the basis of a geometric progression rather than an arithmetic progression • The modern magnitude classification: a difference of 5 magnitudes to equal exactly a factor of 100 in apparent brightness • If m1 and m2 are the apparent magnitudes with apparent bri ...
... • The responce of the human eye works on the basis of a geometric progression rather than an arithmetic progression • The modern magnitude classification: a difference of 5 magnitudes to equal exactly a factor of 100 in apparent brightness • If m1 and m2 are the apparent magnitudes with apparent bri ...
The life cycle of a star
... When extremely large stars die, the resulting core is called a neutron star An extremely dense star made of neutrons ...
... When extremely large stars die, the resulting core is called a neutron star An extremely dense star made of neutrons ...
PHYSICS 113 Assignment #9 SOLUTIONS Chapter 17 13. Starting
... 14. Why do we know less about the formation of galaxies than about the formation of stars? Stars can be seen forming nearby, and we can make detailed observations of what goes on when stars form. Most, if not all, galaxies formed when the universe was young. In order to study how they form, we must ...
... 14. Why do we know less about the formation of galaxies than about the formation of stars? Stars can be seen forming nearby, and we can make detailed observations of what goes on when stars form. Most, if not all, galaxies formed when the universe was young. In order to study how they form, we must ...
Review 2
... Parts of Chapters 13-14-15: Main features of Uranus and Neptune and of the Galilean moons of Jupiter. Structure of a comet. The asteroid belt and the Oort cloud. Why do we have meteor showers during specific days of a year? Chapter 16: How do we use the atomic emission and absorption spectra to find ...
... Parts of Chapters 13-14-15: Main features of Uranus and Neptune and of the Galilean moons of Jupiter. Structure of a comet. The asteroid belt and the Oort cloud. Why do we have meteor showers during specific days of a year? Chapter 16: How do we use the atomic emission and absorption spectra to find ...
1 Ay 124 Winter 2014 – HOMEWORK #2 Problem 1
... than 1M , whose lifetimes are shorter than the age of the galaxy. a) Find the slope x such that an observer in a homogeneous, isotropic region counts, at every apparent bolmetric magnitude, equal numbers of stars in each octave of luminosity. What type of star dominates the counts if x is flatter t ...
... than 1M , whose lifetimes are shorter than the age of the galaxy. a) Find the slope x such that an observer in a homogeneous, isotropic region counts, at every apparent bolmetric magnitude, equal numbers of stars in each octave of luminosity. What type of star dominates the counts if x is flatter t ...
Review Game
... 38) An object compacted to such a small size that light cannot escape from its gravitational field is called a: 39) The spherical surface of space which defines the "surface" of a black hole is the: 40) White dwarfs, like Sirius B, would be found to the ________ on the H-R diagram. 41) A red supergi ...
... 38) An object compacted to such a small size that light cannot escape from its gravitational field is called a: 39) The spherical surface of space which defines the "surface" of a black hole is the: 40) White dwarfs, like Sirius B, would be found to the ________ on the H-R diagram. 41) A red supergi ...
The Life Cycle of Stars Webquest
... 1. In this webquest, you will learn how to identify stars by their magnitude, color, temperature, and spectral class. 2. You will investigate the process of nuclear fusion explained by Einstein's famous equation E = MC2 and learn how mass in the form of hydrogen atoms is converted to helium and caus ...
... 1. In this webquest, you will learn how to identify stars by their magnitude, color, temperature, and spectral class. 2. You will investigate the process of nuclear fusion explained by Einstein's famous equation E = MC2 and learn how mass in the form of hydrogen atoms is converted to helium and caus ...
The Life Cycle of Stars Webquest
... 1. In this webquest, you will learn how to identify stars by their magnitude, color, temperature, and spectral class. 2. You will investigate the process of nuclear fusion explained by Einstein's famous equation E = MC2 and learn how mass in the form of hydrogen atoms is converted to helium and caus ...
... 1. In this webquest, you will learn how to identify stars by their magnitude, color, temperature, and spectral class. 2. You will investigate the process of nuclear fusion explained by Einstein's famous equation E = MC2 and learn how mass in the form of hydrogen atoms is converted to helium and caus ...
Document
... • If you know how luminous a star REALLY is and how bright it looks from Earth, you can determine how far away it must be to look that faint. • For any star in the sky, we KNOW: ...
... • If you know how luminous a star REALLY is and how bright it looks from Earth, you can determine how far away it must be to look that faint. • For any star in the sky, we KNOW: ...
Question C:
... The hard way is to first get the temperature of a B0 star from Figure 13-6 (25,000K), and calculate B−V=−0.52 using Equation 11-11a (although it is not meant for such hot stars). c. (5 pt): In a certain star, hydrogen absorption lines are easily observed, but calcium and iron lines are also obvious. ...
... The hard way is to first get the temperature of a B0 star from Figure 13-6 (25,000K), and calculate B−V=−0.52 using Equation 11-11a (although it is not meant for such hot stars). c. (5 pt): In a certain star, hydrogen absorption lines are easily observed, but calcium and iron lines are also obvious. ...
Test 3 Version 3 1. Milky Way halo stars follow: (a) differential
... 19. The observed temperature of the microwave background is nearly: (a) 3 K, (b) 10 K, (c) 30 K, (d) 100 K, (e) 1000 K. 20. The age of the universe is estimated by astronomers to be about: (a) 50,000 years, (b) 4.6 billion years, (c) 14 billion years, (d) 24 billion years, (e) 1 trillion years. 21. ...
... 19. The observed temperature of the microwave background is nearly: (a) 3 K, (b) 10 K, (c) 30 K, (d) 100 K, (e) 1000 K. 20. The age of the universe is estimated by astronomers to be about: (a) 50,000 years, (b) 4.6 billion years, (c) 14 billion years, (d) 24 billion years, (e) 1 trillion years. 21. ...
Measuring large distances
... So based on the color of a star, and how bright it is, it’s possible to make a guess about how far away the star is. ...
... So based on the color of a star, and how bright it is, it’s possible to make a guess about how far away the star is. ...
PSC100 Transparant Replacement for Chapter 8 Measurement of
... Stellar Parallax * Measure angle to star at two different times. * Use largest base line possible, the diameter of Earth’s orbit around the Sun * This means data readings must be taken 6 months apart. * Calculate distance using triangulation. Spectroscopic Parallax * Once a star is plotted on an H-R ...
... Stellar Parallax * Measure angle to star at two different times. * Use largest base line possible, the diameter of Earth’s orbit around the Sun * This means data readings must be taken 6 months apart. * Calculate distance using triangulation. Spectroscopic Parallax * Once a star is plotted on an H-R ...
Stellar evolution
... - First occurs in a runaway process: "the helium flash". Energy from fusion goes into re-expanding and cooling the core. This slows fusion, so star gets dimmer again. - Then stable He -> C burning. Still have H -> He shell burning surrounding it. ...
... - First occurs in a runaway process: "the helium flash". Energy from fusion goes into re-expanding and cooling the core. This slows fusion, so star gets dimmer again. - Then stable He -> C burning. Still have H -> He shell burning surrounding it. ...
Study Guide 4 Part A Outline
... o Hard to tell where Sun is located, due to absorption by dust. Star counts gave wrong answer. Pulsating variable stars in globular clusters finally showed that Sun is far from the center. o This all culminated in the Curtis-Shapley debate (1920). The issues were: The position of the Sun withi ...
... o Hard to tell where Sun is located, due to absorption by dust. Star counts gave wrong answer. Pulsating variable stars in globular clusters finally showed that Sun is far from the center. o This all culminated in the Curtis-Shapley debate (1920). The issues were: The position of the Sun withi ...
Chapter 28 – Stars and Galaxies
... 3. If the same size, hotter one would be brighter 4. Types of magnitude a. Absolute – as if all stars were same distance from earth b. Apparent – as they appear in the nighttime sky H. Variable Stars 1. Some stars show regular variation of brightness over cycles that last from days to years 2. Cephe ...
... 3. If the same size, hotter one would be brighter 4. Types of magnitude a. Absolute – as if all stars were same distance from earth b. Apparent – as they appear in the nighttime sky H. Variable Stars 1. Some stars show regular variation of brightness over cycles that last from days to years 2. Cephe ...
HR-diagram - Bakersfield College
... Magnitude is measured using (-) and (+) numbers the more (-) the number, the brighter the more (+), the dimmer the star ...
... Magnitude is measured using (-) and (+) numbers the more (-) the number, the brighter the more (+), the dimmer the star ...
Stars and Galaxies – Notes
... Many stars are found in multiple-star systems. Alpha Centauri is in a multiple star system. It is made up of three stars called a triple star system. Over half of the stars in the sky have at least one companion star. Most of these stars are doublestar systems in which two stars revolve around each ...
... Many stars are found in multiple-star systems. Alpha Centauri is in a multiple star system. It is made up of three stars called a triple star system. Over half of the stars in the sky have at least one companion star. Most of these stars are doublestar systems in which two stars revolve around each ...
Sep 2017 - What`s Out Tonight?
... cury, Venus, Mars, Jupiter and Saturn. Venus is extremely bright Open clusters reside in our Milky Way Galaxy. Our Sun is no and hugs close to the Sun, so you see it for a short time in the longer in its group. west after sunset or in the east before sunrise. Jupiter can be out Globular Clusters loo ...
... cury, Venus, Mars, Jupiter and Saturn. Venus is extremely bright Open clusters reside in our Milky Way Galaxy. Our Sun is no and hugs close to the Sun, so you see it for a short time in the longer in its group. west after sunset or in the east before sunrise. Jupiter can be out Globular Clusters loo ...
Eagle Nebula - Amazing Space
... radiation heats the surrounding gas, making it glow. This intense radiation is responsible for sculpting the columns; it erodes more tenuous gas in the columns through a process called photoevaporation. The erosion reveals denser gas globules surrounding newly formed stars (see close-up, right). Sci ...
... radiation heats the surrounding gas, making it glow. This intense radiation is responsible for sculpting the columns; it erodes more tenuous gas in the columns through a process called photoevaporation. The erosion reveals denser gas globules surrounding newly formed stars (see close-up, right). Sci ...
supernova!
... We cannot tell, from its outward appearance, that a particular star is on the verge of using up its last bit of fuel in the core and is about to explode! There is no obvious “fuse” we can watch, gradually counting down the seconds. ...
... We cannot tell, from its outward appearance, that a particular star is on the verge of using up its last bit of fuel in the core and is about to explode! There is no obvious “fuse” we can watch, gradually counting down the seconds. ...
Serpens
Serpens (""the Serpent"", Greek Ὄφις) is a constellation of the northern hemisphere. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations defined by the International Astronomical Union. It is unique among the modern constellations in being split into two non-contiguous parts, Serpens Caput (Serpent's Head) to the west and Serpens Cauda (Serpent's Tail) to the east. Between these two halves lies the constellation of Ophiuchus, the ""Serpent-Bearer"". In figurative representations, the body of the serpent is represented as passing behind Ophiuchus between Mu Serpentis in Serpens Caput and Nu Serpentis in Serpens Cauda.The brightest star in Serpens is the red giant star Alpha Serpentis, or Unukalhai, in Serpens Caput, with an apparent magnitude of 2.63. Also located in Serpens Caput are the naked-eye globular cluster Messier 5 and the naked-eye variables R Serpentis and Tau4 Serpentis. Notable extragalactic objects include Seyfert's Sextet, one of the densest galaxy clusters known; Arp 220, the prototypical ultraluminous infrared galaxy; and Hoag's Object, the most famous of the very rare class of galaxies known as ring galaxies.Part of the Milky Way's galactic plane passes through Serpens Cauda, which is therefore rich in galactic deep-sky objects, such as the Eagle Nebula (IC 4703) and its associated star cluster Messier 16. The nebula measures 70 light-years by 50 light-years and contains the Pillars of Creation, three dust clouds that became famous for the image taken by the Hubble Space Telescope. Other striking objects include the Red Square Nebula, one of the few objects in astronomy to take on a square shape; and Westerhout 40, a massive nearby star-forming region consisting of a molecular cloud and an H II region.