How Marius Was Right and Galileo Was Wrong Even Though
... lights of varying size on a stellar sphere. ...
... lights of varying size on a stellar sphere. ...
Fulltext PDF - Indian Academy of Sciences
... same shape and only change in orientation. In this case, there would be no change in the distance between the Sun and any star. Hence there would be no Doppler shift. However, there would be proper motion since the direction of the Sun-star line would rotate at Ω. This contributes a term independent ...
... same shape and only change in orientation. In this case, there would be no change in the distance between the Sun and any star. Hence there would be no Doppler shift. However, there would be proper motion since the direction of the Sun-star line would rotate at Ω. This contributes a term independent ...
Quasars: Back to the Infant Universe
... to our Galaxy (~ 60 million light years away in the Virgo Cluster) ! M87 has a huge radio jet, about 5000 light-years long ...
... to our Galaxy (~ 60 million light years away in the Virgo Cluster) ! M87 has a huge radio jet, about 5000 light-years long ...
Polaris
... reached a minimum of 1% in the mid 1990s and has remained at a low level. Over the same period, the star has brightened by 15% (on average), and the period has lengthened by about 8 seconds each year. Recent research reported in Science suggests that Polaris is 2.5 times brighter today than when Pt ...
... reached a minimum of 1% in the mid 1990s and has remained at a low level. Over the same period, the star has brightened by 15% (on average), and the period has lengthened by about 8 seconds each year. Recent research reported in Science suggests that Polaris is 2.5 times brighter today than when Pt ...
Mergers of massive main sequence binaries
... data of this analysis to simulate a cluster of a large number of stars with a binary percentage of 50% which formed instantaneously. The result of this simulation is that merger stars of close massive main-sequence binaries are dominant among the most luminous stars in the main-sequence band of the ...
... data of this analysis to simulate a cluster of a large number of stars with a binary percentage of 50% which formed instantaneously. The result of this simulation is that merger stars of close massive main-sequence binaries are dominant among the most luminous stars in the main-sequence band of the ...
Stars in the Sky Stars in the Sky
... that light travels through space in 1 year. Because the speed of light through space is about 300,000 km/s, it travels approximately 9.46 trillion kilometers in 1 year! Figure 6 below illustrates how far away some stars that we see really are. Even after astronomers figured out that stars were far a ...
... that light travels through space in 1 year. Because the speed of light through space is about 300,000 km/s, it travels approximately 9.46 trillion kilometers in 1 year! Figure 6 below illustrates how far away some stars that we see really are. Even after astronomers figured out that stars were far a ...
Constraints on the Production of Ultra–High
... orders of magnitude too low. Observations of pulsar birth velocities (see below) tell us that the kinetic energy of neutron stars could easily account for cosmic rays ; at a median space velocity of 500 km s~1 the energy per neutron star is B4 ] 1048 ergs. To tap that energy the star must be slowed ...
... orders of magnitude too low. Observations of pulsar birth velocities (see below) tell us that the kinetic energy of neutron stars could easily account for cosmic rays ; at a median space velocity of 500 km s~1 the energy per neutron star is B4 ] 1048 ergs. To tap that energy the star must be slowed ...
Where is the best site on Earth? Dome A, B, C and F, and Ridges A
... remarkably similar, at a lebel ～23m/arcmin^2 The optical sky brightness at Dome F is dominated by aurorae, most of the time. ...
... remarkably similar, at a lebel ～23m/arcmin^2 The optical sky brightness at Dome F is dominated by aurorae, most of the time. ...
Lecture 28 Formation of chemical elements
... elements heavier than He. We must look beyond our solar system for the birth of the elements that comprise it. Before we can understand the processes that make the chemical elements, we should look at the processes that formed matter itself. GG325 L28, F2013 ...
... elements heavier than He. We must look beyond our solar system for the birth of the elements that comprise it. Before we can understand the processes that make the chemical elements, we should look at the processes that formed matter itself. GG325 L28, F2013 ...
1. INTRODUCTION - Institut für Theoretische Astrophysik
... explanation of basal heating is that it may be caused by heating due to intrinsically weak magnetic Ðelds generated by the dynamo mechanism working at a very low stellar rotation rate or by convective turbulence of the partly ionized matter. Furthermore, those magnetic Ðelds could also be a leftover ...
... explanation of basal heating is that it may be caused by heating due to intrinsically weak magnetic Ðelds generated by the dynamo mechanism working at a very low stellar rotation rate or by convective turbulence of the partly ionized matter. Furthermore, those magnetic Ðelds could also be a leftover ...
The Final Version of the White Paper is available.
... The discovery almost 20 years ago of the first giant planet outside of the solar system (Mayor & Queloz 1995) spawned a real revolution in astronomy. The completely unexpected characteristics of this first planet captured the imagination and interest of the scientific community and the general publi ...
... The discovery almost 20 years ago of the first giant planet outside of the solar system (Mayor & Queloz 1995) spawned a real revolution in astronomy. The completely unexpected characteristics of this first planet captured the imagination and interest of the scientific community and the general publi ...
Natasha Wood
... Mentors: Marco Ajello & Masaaki Hayashida How will you be doing the comparisons? An active galactic nucleus (AGN) is a relatively small region of space at the center of a galaxy that is very luminous over all or part of the electromagnetic spectrum1. This radiation is theorized to be a product of ma ...
... Mentors: Marco Ajello & Masaaki Hayashida How will you be doing the comparisons? An active galactic nucleus (AGN) is a relatively small region of space at the center of a galaxy that is very luminous over all or part of the electromagnetic spectrum1. This radiation is theorized to be a product of ma ...
Lectures Part 7 - John Boccio Website
... Interferometric detectors are limited at high frequencies by shot noise, which occurs because the lasers produce photons randomly; one analogy is to rainfall - rate of rainfall, like laser intensity, is measurable, but raindrops, like photons, fall at random times, causing fluctuations around averag ...
... Interferometric detectors are limited at high frequencies by shot noise, which occurs because the lasers produce photons randomly; one analogy is to rainfall - rate of rainfall, like laser intensity, is measurable, but raindrops, like photons, fall at random times, causing fluctuations around averag ...
Strong period decrease in the Mira star S Sex: a possible helium
... with the theoretical models of AGB stars in the phases prior to a helium flash process, which predict a very small luminosity increase over several tens of thousand years as a consequence of a stable process of hydrogen-shell burning. When the helium flash occurs, the hydrogen-burning shell is rapid ...
... with the theoretical models of AGB stars in the phases prior to a helium flash process, which predict a very small luminosity increase over several tens of thousand years as a consequence of a stable process of hydrogen-shell burning. When the helium flash occurs, the hydrogen-burning shell is rapid ...
Hubble Space Telescope Image
... . The tiny red dot just left of top center also intrigues researchers. They believe it may be an extremely remote object made visible by the cluster's magnifying powers. This is the second time Hubble observed this cluster. ...
... . The tiny red dot just left of top center also intrigues researchers. They believe it may be an extremely remote object made visible by the cluster's magnifying powers. This is the second time Hubble observed this cluster. ...
General Astrophysics And Comparative Planetology
... Earth-sized based only on visual observations and an assumed surface reflectance. This estimate was reduced when Pluto’s icy nature was guessed. Finally the Charon-Pluto eclipses during the late 1980s constrained Pluto’s radius to be much smaller—0.18 Earth radii. Sedna is a recently discovered smal ...
... Earth-sized based only on visual observations and an assumed surface reflectance. This estimate was reduced when Pluto’s icy nature was guessed. Finally the Charon-Pluto eclipses during the late 1980s constrained Pluto’s radius to be much smaller—0.18 Earth radii. Sedna is a recently discovered smal ...
mass transfer in close, rapidly accreting protobinaries
... that produce high accretion rates. Simple order-of-magnitude estimates for the properties of observed massive protostellar cores suggest that accretion rates of 104 Y102 M yr1 are typical (Krumholz 2006), and both detailed analytic models (McKee & Tan 2003) and numerical simulations (Banerjee & ...
... that produce high accretion rates. Simple order-of-magnitude estimates for the properties of observed massive protostellar cores suggest that accretion rates of 104 Y102 M yr1 are typical (Krumholz 2006), and both detailed analytic models (McKee & Tan 2003) and numerical simulations (Banerjee & ...
sections 16-18 instructor notes
... Trigonometric parallaxes are derived from observable annual parallactic displacements of stars in the sky resulting from the Earth’s orbital motion about the Sun. The systematic motion of the Sun with respect to the local system of stars results in secular displacements in the sky of the observed po ...
... Trigonometric parallaxes are derived from observable annual parallactic displacements of stars in the sky resulting from the Earth’s orbital motion about the Sun. The systematic motion of the Sun with respect to the local system of stars results in secular displacements in the sky of the observed po ...
Observational Constraints on the Most Massive White Dwarf
... The two circled Pleiad white dwarfs were found by Paul Dobbie and collaborators to have kinematic properties suggesting they are escaped from the Pleiades. I plot them in this diagram under the assumption that they once were true members of the star cluster, but the potential remains that the kinema ...
... The two circled Pleiad white dwarfs were found by Paul Dobbie and collaborators to have kinematic properties suggesting they are escaped from the Pleiades. I plot them in this diagram under the assumption that they once were true members of the star cluster, but the potential remains that the kinema ...
The Current Status of Galaxy Formation
... the luminous dwarfs accrete gas at later epochs. Most gas is ejected by the first generations of SNe for < 50 km/s, leaving dim stellar remnants behind. systems with escape velocity ∼ In very low-mass halos gas cannot even fall in, because its specific entropy is too high (Rees, 1986). This entropy ...
... the luminous dwarfs accrete gas at later epochs. Most gas is ejected by the first generations of SNe for < 50 km/s, leaving dim stellar remnants behind. systems with escape velocity ∼ In very low-mass halos gas cannot even fall in, because its specific entropy is too high (Rees, 1986). This entropy ...
Galaxies - Indiana University Astronomy
... Using the same website as above, click on “spectrum” for the two galaxies whose distances you measured. The optical spectrum of the galaxy is shown at the top of the spectrum page. Shown are many different spectral features, including absorption lines and emission lines, superimposed on continuum em ...
... Using the same website as above, click on “spectrum” for the two galaxies whose distances you measured. The optical spectrum of the galaxy is shown at the top of the spectrum page. Shown are many different spectral features, including absorption lines and emission lines, superimposed on continuum em ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.