... a “planet”. First, it was argued that a celestial body can be defined as a planet if it is in orbit around a star while not being itself a star or a satellite. Second, the object must be large enough for its own gravity to pull it into a nearly spherical shape. The shape of objects with mass above 5 ...
Slide 1
... First, a teaspoon of material from one can weigh up to a billion tons. (A large mountain) Second, an entire neutron star would be smaller than the Denver metro area. (3 times the mass of the whole sun!) Third, if you collapse a spinning thing, it speeds way up. Most neutron stars rotate between 3 an ...
... First, a teaspoon of material from one can weigh up to a billion tons. (A large mountain) Second, an entire neutron star would be smaller than the Denver metro area. (3 times the mass of the whole sun!) Third, if you collapse a spinning thing, it speeds way up. Most neutron stars rotate between 3 an ...
Essential physics of early galaxy formation
... further star formation. As halos build-up mass with time, their DM potential well can sustain much larger star formation rates (SFR) without losing gas. This naturally implies that, at any given time, there is a limiting star formation efficiency such that the energy produced by newly-formed stars i ...
... further star formation. As halos build-up mass with time, their DM potential well can sustain much larger star formation rates (SFR) without losing gas. This naturally implies that, at any given time, there is a limiting star formation efficiency such that the energy produced by newly-formed stars i ...
HOPS 383: An Outbursting Class 0 Protostar in Orion
... of a typical solar-mass star accreted in stochastic outbursts or in a smooth process of infall from a circumstellar envelope, through an accretion disk, and onto the star? The likelihood of the former scenario increases as new outbursts are discovered at earlier stages of the star formation process. ...
... of a typical solar-mass star accreted in stochastic outbursts or in a smooth process of infall from a circumstellar envelope, through an accretion disk, and onto the star? The likelihood of the former scenario increases as new outbursts are discovered at earlier stages of the star formation process. ...
How we think the planets were born
... “There is an infinite number of worlds, some like this world, some unlike it… For the atoms out of which a world might arise, or by which a world might be formed, have not all been expended on one world or a finite number of worlds, whether like or unlike this one. Hence there will be nothing to hin ...
... “There is an infinite number of worlds, some like this world, some unlike it… For the atoms out of which a world might arise, or by which a world might be formed, have not all been expended on one world or a finite number of worlds, whether like or unlike this one. Hence there will be nothing to hin ...
PPT
... X-rays from magnetic activity on star UV and X-rays from accretion onto star X-rays from shocks in out-flowing jets ...
... X-rays from magnetic activity on star UV and X-rays from accretion onto star X-rays from shocks in out-flowing jets ...
Detecting Exoplanets Talk
... • The detection and study of exoplanets is really taking off, and will lead to a huge leap in our understanding of how solar systems form, how ubiquitous they are, and ultimately may answer the question, are we alone in the universe. • It is an exciting time, and amateurs with ordinary amateur equip ...
... • The detection and study of exoplanets is really taking off, and will lead to a huge leap in our understanding of how solar systems form, how ubiquitous they are, and ultimately may answer the question, are we alone in the universe. • It is an exciting time, and amateurs with ordinary amateur equip ...
Advances in exoplanet science from Kepler (Lissauer et al. 2014)
... deduce the star’s radius and mass, and from these we can find the planet’s radius and the semi-major axis of its orbit (from Kepler’s third law). In favourable cases (generally restricted to close-in planets that are subject to intense stellar irradiation), we can detect the occultation of the plane ...
... deduce the star’s radius and mass, and from these we can find the planet’s radius and the semi-major axis of its orbit (from Kepler’s third law). In favourable cases (generally restricted to close-in planets that are subject to intense stellar irradiation), we can detect the occultation of the plane ...
Betelgeuse: an unauthorized biography
... “infrared flux” method. This relies on knowledge of the angular diameter α of the star and the flux F of its radiation at Earth. The distance to the star cancels to give Teff = 4F/σα1/2. The problem with the extended atmosphere of a cool supergiant is that the angular diameter depends on wavelength. ...
... “infrared flux” method. This relies on knowledge of the angular diameter α of the star and the flux F of its radiation at Earth. The distance to the star cancels to give Teff = 4F/σα1/2. The problem with the extended atmosphere of a cool supergiant is that the angular diameter depends on wavelength. ...
WARM SATURNS: ON THE NATURE OF RINGS
... We discuss the nature of rings that may exist around extrasolar planets. Taking the general properties of rings around the gas giants in the Solar System, we infer the likely properties of rings around exoplanets that reside inside the ice line. Due to their proximity to their host star, rings aroun ...
... We discuss the nature of rings that may exist around extrasolar planets. Taking the general properties of rings around the gas giants in the Solar System, we infer the likely properties of rings around exoplanets that reside inside the ice line. Due to their proximity to their host star, rings aroun ...
Cosmology with GMRT
... processes (e.g. cooling and collapse) shaping the centers of the dark matter halos even in dwarf galaxies. Alternatively it has been taken as ...
... processes (e.g. cooling and collapse) shaping the centers of the dark matter halos even in dwarf galaxies. Alternatively it has been taken as ...
Discovery and spectroscopy of the young Jovian planet
... that are bright at young ages – referred to as “hot-start”. Alternatively, two-stage formation, first of a dense solid core followed by gas accretion through a shock, as likely in the case of Jupiter, can produce a range of states including lower-entropy planets that are cooler, and slightly smaller ...
... that are bright at young ages – referred to as “hot-start”. Alternatively, two-stage formation, first of a dense solid core followed by gas accretion through a shock, as likely in the case of Jupiter, can produce a range of states including lower-entropy planets that are cooler, and slightly smaller ...
AST1100 Lecture Notes
... When the hydrogen in the core has been exhausted, the forces of pressure are not any longer strong enough to sustain the forces of gravity. The hydrostatic equilibrium is lost and the core starts contracting. During the core contraction, the temperature in and around the core increases. The tempera ...
... When the hydrogen in the core has been exhausted, the forces of pressure are not any longer strong enough to sustain the forces of gravity. The hydrostatic equilibrium is lost and the core starts contracting. During the core contraction, the temperature in and around the core increases. The tempera ...
The Astrobiology Primer
... A blob of gas several times the size of our Solar System, called a pre-stellar core, contracts under its own gravity to form a protostar. Half of the system’s initial gravitational energy disperses through radiation while the other half is converted into heat. The temperature of the core begins to r ...
... A blob of gas several times the size of our Solar System, called a pre-stellar core, contracts under its own gravity to form a protostar. Half of the system’s initial gravitational energy disperses through radiation while the other half is converted into heat. The temperature of the core begins to r ...