Startalk
... A big glowing ball of gas! Contains mainly H and He They have a core that is dense and super hot! Nuclear fusion is the source of their energy! ...
... A big glowing ball of gas! Contains mainly H and He They have a core that is dense and super hot! Nuclear fusion is the source of their energy! ...
White Dwarf Stars Near The Earth
... the “ages” of the white dwarfs on this page, I mean how long they have been white dwarfs, not how long they were main-sequence stars before that.) 40 Eridani B is a member of a triple star system and was once the brightest and most massive of the three, since the other two are relatively cool K-clas ...
... the “ages” of the white dwarfs on this page, I mean how long they have been white dwarfs, not how long they were main-sequence stars before that.) 40 Eridani B is a member of a triple star system and was once the brightest and most massive of the three, since the other two are relatively cool K-clas ...
The HR Diagram Interpreted: Properties of Stars
... Is the Sun an ‘Average’ Star? It is (roughly) in the middle of the range, so it is certainly not unusual. But is it average? Analogy: is a human being an average-sized living creature? We are in the ‘mid-range’, between blue whales and bacteria, giraffes and mice,… But there are many more bacteria ...
... Is the Sun an ‘Average’ Star? It is (roughly) in the middle of the range, so it is certainly not unusual. But is it average? Analogy: is a human being an average-sized living creature? We are in the ‘mid-range’, between blue whales and bacteria, giraffes and mice,… But there are many more bacteria ...
The HR Diagram Interpreted (PowerPoint version)
... Is the Sun an ‘Average’ Star? It is (roughly) in the middle of the range, so it is certainly not unusual. But is it average? Analogy: is a human being an average-sized living creature? We are in the ‘mid-range’, between blue whales and bacteria, giraffes and mice,… But there are many more bacteria ...
... Is the Sun an ‘Average’ Star? It is (roughly) in the middle of the range, so it is certainly not unusual. But is it average? Analogy: is a human being an average-sized living creature? We are in the ‘mid-range’, between blue whales and bacteria, giraffes and mice,… But there are many more bacteria ...
PISGAH Dr. Bob Hayward ASTRONOMICAL Astronomer/Educator
... Go back to the belt of Orion and draw a line to the east. Rising in the southeast is a bright white star. This is Sirius the Dog Star. While Sirius appears to be the brightest star in the nighttime sky, it is not intrinsically the brightest nor is it the closest to us. But it is a combination of bot ...
... Go back to the belt of Orion and draw a line to the east. Rising in the southeast is a bright white star. This is Sirius the Dog Star. While Sirius appears to be the brightest star in the nighttime sky, it is not intrinsically the brightest nor is it the closest to us. But it is a combination of bot ...
White Dwarfs - Astronomy - The University of Texas at Austin
... White Dwarfs (Section 5.1) Essentially every white dwarf formed since beginning of Galaxy is still here 10-100 billion of them (~ 100 billion stars total) Most are dim, undiscovered, see only those nearby, none naked eye Sirius, brightest star in the sky, has a white dwarf companion. Can’t see the ...
... White Dwarfs (Section 5.1) Essentially every white dwarf formed since beginning of Galaxy is still here 10-100 billion of them (~ 100 billion stars total) Most are dim, undiscovered, see only those nearby, none naked eye Sirius, brightest star in the sky, has a white dwarf companion. Can’t see the ...
Sky Notes - February 2012 - North Devon Astronomical Society
... surface temperature of around 10,000 degrees Celcius - about twice as hot as our Sun. In fact, it’s name is derived from the Greek ‘Seirios’ meaning ‘glowing’ or ‘scorcher’ - very appropriate. In addition, the star is somewhat larger than the Sun, more than twice as massive and around 25 times as lu ...
... surface temperature of around 10,000 degrees Celcius - about twice as hot as our Sun. In fact, it’s name is derived from the Greek ‘Seirios’ meaning ‘glowing’ or ‘scorcher’ - very appropriate. In addition, the star is somewhat larger than the Sun, more than twice as massive and around 25 times as lu ...
Thursday October 1 - Montana State University
... What if all stars had the same luminosity? • Luminosity means total power output as light. • Determining their distance from us would be easy if they all were the same luminosity! ...
... What if all stars had the same luminosity? • Luminosity means total power output as light. • Determining their distance from us would be easy if they all were the same luminosity! ...
Astronomy 20 Homework # 2
... a 1-hour exposure? From the foreground sky? If a blank piece of sky is measured at the same time in order to subtract the sky spectrum from the total, what is the signal-to-noise ratio per resolution element in the final, sky-subtracted galaxy spectrum? (Neglect the detector noise, and assume a pure ...
... a 1-hour exposure? From the foreground sky? If a blank piece of sky is measured at the same time in order to subtract the sky spectrum from the total, what is the signal-to-noise ratio per resolution element in the final, sky-subtracted galaxy spectrum? (Neglect the detector noise, and assume a pure ...
Winter constellations
... December evenings are a great time to see the wonderful winter constellation of Orion, Taurus, Sirius and the Pleiades. Orion, the Hunter (to the medieval Arab astronomers, the Giant), with the triplets of stars of his belt and sword, and to the upper left the bright red star Betelgeuse. The name me ...
... December evenings are a great time to see the wonderful winter constellation of Orion, Taurus, Sirius and the Pleiades. Orion, the Hunter (to the medieval Arab astronomers, the Giant), with the triplets of stars of his belt and sword, and to the upper left the bright red star Betelgeuse. The name me ...
December 2014 - Coconino Astronomical Society
... of wonder and veneration to most ancient peoples throughout human history. To the ancient Egyptians, Sirius was revered as the Nile Star, or the Soul of Isis. Its annual appearance just before dawn at the summer solstice heralded the rising of the Nile waters upon which Egyptian agriculture depended ...
... of wonder and veneration to most ancient peoples throughout human history. To the ancient Egyptians, Sirius was revered as the Nile Star, or the Soul of Isis. Its annual appearance just before dawn at the summer solstice heralded the rising of the Nile waters upon which Egyptian agriculture depended ...
Star and Sun Properties
... gas and that emits light; the sun is a typical star • The Sun, our closest star, is 93 million miles from Earth. • The next closest star is 4.3 lighter years away. • By mass, the Sun is 71 % Hydrogen, 27% helium and the rest heavier element. This is similar to the composition of the universe. • The ...
... gas and that emits light; the sun is a typical star • The Sun, our closest star, is 93 million miles from Earth. • The next closest star is 4.3 lighter years away. • By mass, the Sun is 71 % Hydrogen, 27% helium and the rest heavier element. This is similar to the composition of the universe. • The ...
Mountain Skies February 8 2016 - Pisgah Astronomical Research
... each fifty years. Because Sirius A is so much brighter, it is hard to spot Sirius B when they are close together. However, their mutual orbits are very elliptical and they were at their closest point in 1994. Thus, we have entered a period of time when they are appearing progressively farther apart; ...
... each fifty years. Because Sirius A is so much brighter, it is hard to spot Sirius B when they are close together. However, their mutual orbits are very elliptical and they were at their closest point in 1994. Thus, we have entered a period of time when they are appearing progressively farther apart; ...
The Hot-plate Model of a Star Model of Stars— 3 Oct
... • Definition of apparent magnitude – The magnitude of Vega is 0. – For every factor of 10 fainter, the magnitude is 2.5 greater. ...
... • Definition of apparent magnitude – The magnitude of Vega is 0. – For every factor of 10 fainter, the magnitude is 2.5 greater. ...
a. Recognize the physical attributes of stars in the night sky such as
... How are all stars alike? a. They are the same age. b. They are the same size. c. They are the same color. d. They are all balls of hot gases. Answer: d Stars appear as small points of light in the sky because ________________. a. they are so much dimmer than the sun b. they are so much smaller than ...
... How are all stars alike? a. They are the same age. b. They are the same size. c. They are the same color. d. They are all balls of hot gases. Answer: d Stars appear as small points of light in the sky because ________________. a. they are so much dimmer than the sun b. they are so much smaller than ...
Sirius
Sirius (/ˈsɪriəs/) is the brightest star (in fact, a star system) in the Earth's night sky. With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star. The name ""Sirius"" is derived from the Ancient Greek Σείριος (Seirios), meaning ""glowing"" or ""scorcher"". The system has the Bayer designation Alpha Canis Majoris (α CMa). What the naked eye perceives as a single star is actually a binary star system, consisting of a white main-sequence star of spectral type A1V, termed Sirius A, and a faint white dwarf companion of spectral type DA2, called Sirius B. The distance separating Sirius A from its companion varies between 8.2 and 31.5 AU.Sirius appears bright because of both its intrinsic luminosity and its proximity to Earth. At a distance of 2.6 parsecs (8.6 ly), as determined by the Hipparcos astrometry satellite, the Sirius system is one of Earth's near neighbors. Sirius is gradually moving closer to the Solar System, so it will slightly increase in brightness over the next 60,000 years. After that time its distance will begin to increase, but it will continue to be the brightest star in the Earth's sky for the next 210,000 years.Sirius A is about twice as massive as the Sun (M☉) and has an absolute visual magnitude of 1.42. It is 25 times more luminous than the Sun but has a significantly lower luminosity than other bright stars such as Canopus or Rigel. The system is between 200 and 300 million years old. It was originally composed of two bright bluish stars. The more massive of these, Sirius B, consumed its resources and became a red giant before shedding its outer layers and collapsing into its current state as a white dwarf around 120 million years ago.Sirius is also known colloquially as the ""Dog Star"", reflecting its prominence in its constellation, Canis Major (Greater Dog). The heliacal rising of Sirius marked the flooding of the Nile in Ancient Egypt and the ""dog days"" of summer for the ancient Greeks, while to the Polynesians in the Southern Hemisphere the star marked winter and was an important reference for their navigation around the Pacific Ocean.