Lecture 14
... be too small to measure accurately. The smallest parallax measurable from the ground is about 0.01 arcsec • Measure distances out to ~100 pc • But, only a few hundred stars are this close to the Sun ASTR111 Lecture 14 ...
... be too small to measure accurately. The smallest parallax measurable from the ground is about 0.01 arcsec • Measure distances out to ~100 pc • But, only a few hundred stars are this close to the Sun ASTR111 Lecture 14 ...
Stellar Masses
... stably. Objects with masses slightly below this limit are called brown dwarfs, and are ‘star like’ in the sense that nuclear burning of deuterium occurs in their core. Below a mass of 0.015M⊙ (roughly 16 times the mass of Jupiter) not even deuterium burning can occur, and these objects are perhaps b ...
... stably. Objects with masses slightly below this limit are called brown dwarfs, and are ‘star like’ in the sense that nuclear burning of deuterium occurs in their core. Below a mass of 0.015M⊙ (roughly 16 times the mass of Jupiter) not even deuterium burning can occur, and these objects are perhaps b ...
Red supergiants and the past of Cygnus OB2
... Methods. Near-infrared star counts in the Cygnus region reveal moderate evidence for a peak in the areal density of bright, reddened stars approximately coincident with Cygnus OB2. A total of 11 sources are found within a circle of 1◦ radius centered on the association, of which 4 are non-supergiant ...
... Methods. Near-infrared star counts in the Cygnus region reveal moderate evidence for a peak in the areal density of bright, reddened stars approximately coincident with Cygnus OB2. A total of 11 sources are found within a circle of 1◦ radius centered on the association, of which 4 are non-supergiant ...
AST1100 Lecture Notes
... we do have several methods available which are based on different and independent assumptions. Using cross-checks between these different methods we can often obtain more exact distance measurements. Why do we want to measure distances to distant objects in the universe? In order to understand the p ...
... we do have several methods available which are based on different and independent assumptions. Using cross-checks between these different methods we can often obtain more exact distance measurements. Why do we want to measure distances to distant objects in the universe? In order to understand the p ...
Neutron Stars
... Periods shorter than this do not exist (such as in the previous calculation) because the object would have to rotate so fast it would overcome gravity and fly apart. ...
... Periods shorter than this do not exist (such as in the previous calculation) because the object would have to rotate so fast it would overcome gravity and fly apart. ...
How Many Stars in the Sky?
... age. Stars vary in brightness, color, mass, temperature, and age. Stars are classified by colors as related to their surface temperature. The coolest stars are orange, then red, yellow, green, blue and finally blue-white. The size of a star on a photograph tells us about its brightness. Large star ...
... age. Stars vary in brightness, color, mass, temperature, and age. Stars are classified by colors as related to their surface temperature. The coolest stars are orange, then red, yellow, green, blue and finally blue-white. The size of a star on a photograph tells us about its brightness. Large star ...
... the finite speed of light to measure distances. However, stars are so far away and such poor reflectors that this approach is impractical (though it is used to determine distances to planets in our solar system). The question of measuring star distances has occupied astronomers at least since the ti ...
Slide
... • Distances to several thousand stars are known this way. • The Hipparcos satellite extends the distance to ~200 pc, so distances to nearly one million stars can be measured with parallax. ...
... • Distances to several thousand stars are known this way. • The Hipparcos satellite extends the distance to ~200 pc, so distances to nearly one million stars can be measured with parallax. ...
AST1100 Lecture Notes
... Several stars show periodic changes in their apparent magnitudes. This was first thought to be caused by dark spots on a rotating star’s surface: When the dark spots were turned towards us, the star appeared fainter, when the spots were turned away from us, the star appeared brighter. Today we know ...
... Several stars show periodic changes in their apparent magnitudes. This was first thought to be caused by dark spots on a rotating star’s surface: When the dark spots were turned towards us, the star appeared fainter, when the spots were turned away from us, the star appeared brighter. Today we know ...
Stellar Properties
... • a star could be very bright because is was very close to us; not because it was truly bright • two stars in the same constellation might not be close to each other; one could be much farther away ...
... • a star could be very bright because is was very close to us; not because it was truly bright • two stars in the same constellation might not be close to each other; one could be much farther away ...
Lecture8_v2 - Lick Observatory
... 2. After gas disk cleared away, several giant planets in outer parts of solar system were left – Three-body gravitational interactions between them – One giant planet got slung outwards, a second was slung inwards and got “captured” by the star in a close orbit ...
... 2. After gas disk cleared away, several giant planets in outer parts of solar system were left – Three-body gravitational interactions between them – One giant planet got slung outwards, a second was slung inwards and got “captured” by the star in a close orbit ...
White Dwarf Stars - Stellar Physics Department
... And finally to complete the classification, a temperature index can follow their spectral classification. This index is defined as θ = 50400/Teff . Therefore, a white dwarf showing Balmer lines with an effective temperature of 20 000 K will be classified DA2.5. The temperature index is not always pr ...
... And finally to complete the classification, a temperature index can follow their spectral classification. This index is defined as θ = 50400/Teff . Therefore, a white dwarf showing Balmer lines with an effective temperature of 20 000 K will be classified DA2.5. The temperature index is not always pr ...
1 Introduction - High Point University
... Table 6: Fill in the empty fields above. 3. Check show luminosity classes and show isoradius lines (if they are not already checked). The green region (Dwarfs (V)) is known as the main sequence and contains all stars that are fusing hydrogen into helium as their primary energy source. Over 90% of al ...
... Table 6: Fill in the empty fields above. 3. Check show luminosity classes and show isoradius lines (if they are not already checked). The green region (Dwarfs (V)) is known as the main sequence and contains all stars that are fusing hydrogen into helium as their primary energy source. Over 90% of al ...
Part1
... (broad), and narrow features (lines) … o other shape at very long (synchrotron, thin free free) … o mm and radio emission is a footnote (useful as a tracer of conditions). ...
... (broad), and narrow features (lines) … o other shape at very long (synchrotron, thin free free) … o mm and radio emission is a footnote (useful as a tracer of conditions). ...
Title: Binary interaction dominates the evolution of massive stars
... evolution. Because star cluster dynamics and stellar evolution could have affected the multiplicity properties of only very few of the young O stars in our sample (see supporting online material §A.2), our derived distributions are a good representation of the binary properties at birth. Thus it is ...
... evolution. Because star cluster dynamics and stellar evolution could have affected the multiplicity properties of only very few of the young O stars in our sample (see supporting online material §A.2), our derived distributions are a good representation of the binary properties at birth. Thus it is ...
EX PLANET E - Institute of Physics
... percentage of brightness on the y-axis and the time on the x-axis. An idealised light curve for a Jupiter-like planet crossing the disc of a Sun-like star is shown in figure 1a. On their worksheet, students are provided with a light curve and asked to sketch curves for a faster and a bigger planet. ...
... percentage of brightness on the y-axis and the time on the x-axis. An idealised light curve for a Jupiter-like planet crossing the disc of a Sun-like star is shown in figure 1a. On their worksheet, students are provided with a light curve and asked to sketch curves for a faster and a bigger planet. ...
Table of Contents - Shawnee State University
... - Winds between the Big and Little Dippers. - Generally takes up all of the remaining bright stars between those two constellations. - Draco’s head hangs down near Cepheus. - Draco is probably the toughest circumpolar constellation to find, - If you can find it, you could tell the ‘dragon heaven’ st ...
... - Winds between the Big and Little Dippers. - Generally takes up all of the remaining bright stars between those two constellations. - Draco’s head hangs down near Cepheus. - Draco is probably the toughest circumpolar constellation to find, - If you can find it, you could tell the ‘dragon heaven’ st ...
26.2 Stars - Clinton Public Schools
... Most stars are found along a diagonal band running from the bright hot stars on the upper left to the dim cool stars on the lower right. Astronomers call this diagonal band on the H-R diagram the main sequence. About 90% of all stars are found on the main sequence. The sun lies near the middle of th ...
... Most stars are found along a diagonal band running from the bright hot stars on the upper left to the dim cool stars on the lower right. Astronomers call this diagonal band on the H-R diagram the main sequence. About 90% of all stars are found on the main sequence. The sun lies near the middle of th ...
Lyra
Lyra (/ˈlaɪərə/; Latin for lyre, from Greek λύρα) is a small constellation. It is one of 48 listed by the 2nd century astronomer Ptolemy, and is one of the 88 constellations recognized by the International Astronomical Union. Lyra was often represented on star maps as a vulture or an eagle carrying a lyre, and hence sometimes referred to as Aquila Cadens or Vultur Cadens. Beginning at the north, Lyra is bordered by Draco, Hercules, Vulpecula, and Cygnus. Lyra is visible from the northern hemisphere from spring through autumn, and nearly overhead, in temperate latitudes, during the summer months. From the southern hemisphere, it is visible low in the northern sky during the winter months.The lucida or brightest star—and one of the brightest stars in the sky—is the white main sequence star Vega, a corner of the Summer Triangle. Beta Lyrae is the prototype of a class of stars known as Beta Lyrae variables, binary stars so close to each other that they become egg-shaped and material flows from one to the other. Epsilon Lyrae, known informally as the Double Double, is a complex multiple star system. Lyra also hosts the Ring Nebula, the second-discovered and best-known planetary nebula.