IAC_L2_thindisk
... the disk, e.g. via Jeans equation. Is there more matter in the disk that we can account for from census of visible objects ? The tracer sample must be in equilibrium so the stars need to be older than a few Gyr. The last few estimates have used K dwarfs and K giants - probably OK but they do include ...
... the disk, e.g. via Jeans equation. Is there more matter in the disk that we can account for from census of visible objects ? The tracer sample must be in equilibrium so the stars need to be older than a few Gyr. The last few estimates have used K dwarfs and K giants - probably OK but they do include ...
Trapezium Fracture
... their formation. Thousands of proto-solar systems evolving within the nebula will be destroyed by the trapezium, within 100,000 years before they have a chance to coalesce into fully formed systems. Only a relative few of the more distant systems will survive the brilliant but short lived super gian ...
... their formation. Thousands of proto-solar systems evolving within the nebula will be destroyed by the trapezium, within 100,000 years before they have a chance to coalesce into fully formed systems. Only a relative few of the more distant systems will survive the brilliant but short lived super gian ...
1998 - Universitäts-Sternwarte München
... demonstrated by the recent discovery of the Sagittarius dwarf galaxy merger. This striking example, in particular, represents a far-reaching alert to closed box models or other simplified assumptions, in spite of their analytical beauties. Similarly, the system of Galactic globular clusters has been ...
... demonstrated by the recent discovery of the Sagittarius dwarf galaxy merger. This striking example, in particular, represents a far-reaching alert to closed box models or other simplified assumptions, in spite of their analytical beauties. Similarly, the system of Galactic globular clusters has been ...
Unlocking the secrets of stellar haloes using combined star counts
... In recent years, most attempts to trace the surface brightness profiles of stellar haloes have been based on direct star counts, i.e. by counting the number of bright halo stars (red giant branch stars, asymptotic giant branch stars and upper main sequence stars) within a certain area. The bright st ...
... In recent years, most attempts to trace the surface brightness profiles of stellar haloes have been based on direct star counts, i.e. by counting the number of bright halo stars (red giant branch stars, asymptotic giant branch stars and upper main sequence stars) within a certain area. The bright st ...
GALAXIES 626
... Kinematics and structure of the thick disk rotational lag ~ 30 km/s near the sun and increases by about 30 km s-1 kpc-1 with height above the plane velocity dispersion in (U,V,W) = (46, 50, 35) km/s radial scale length = 3.5 to 4.5 kpc : uncertain scale height from star counts = 800 to 1200 pc (thi ...
... Kinematics and structure of the thick disk rotational lag ~ 30 km/s near the sun and increases by about 30 km s-1 kpc-1 with height above the plane velocity dispersion in (U,V,W) = (46, 50, 35) km/s radial scale length = 3.5 to 4.5 kpc : uncertain scale height from star counts = 800 to 1200 pc (thi ...
The Age Distribution of Potential Intelligent Life in the Milky Way
... proxy. To do this we created a galactic chemical evolution model and applied the following habitability constraints to the Sun-like (G-type) stars formed in our model: an environment free from life-extinguishing supernovae, a high enough metallicity for Earth-sized planet formation and sufficient ti ...
... proxy. To do this we created a galactic chemical evolution model and applied the following habitability constraints to the Sun-like (G-type) stars formed in our model: an environment free from life-extinguishing supernovae, a high enough metallicity for Earth-sized planet formation and sufficient ti ...
Infrared Properties of Star-Forming Dwarf Galaxies. I. Dwarf Irregular
... 1. Detection of the [O iii] k4363 emission line for the determination of oxygen abundances. 2. A reliable distance (i.e., determined from stellar constituents, such as Cepheids and the tip of the RGB [TRGB]). ...
... 1. Detection of the [O iii] k4363 emission line for the determination of oxygen abundances. 2. A reliable distance (i.e., determined from stellar constituents, such as Cepheids and the tip of the RGB [TRGB]). ...
GALEX and Star Formation
... MW”-type dust (and moderate extinction amounts). In fact, although the selective extinction Aλ /EB−V increases towards shorter wavelengths, the GALEX ∼1000Å-wide NUV band entirely includes the strong broad aborption feature at 2175Å (Fig. 4), and therefore the overall absorption is not too differe ...
... MW”-type dust (and moderate extinction amounts). In fact, although the selective extinction Aλ /EB−V increases towards shorter wavelengths, the GALEX ∼1000Å-wide NUV band entirely includes the strong broad aborption feature at 2175Å (Fig. 4), and therefore the overall absorption is not too differe ...
Observational studies of stellar rotation
... months to years (e.g. Affer et al. 2012; McQuillan et al. 2013). The large number of rotational cycles recorded by these light curves allows not only the stellar rotational period to be derived with extreme accuracy but also to detect latitudinal differential rotation by traking spots located at dif ...
... months to years (e.g. Affer et al. 2012; McQuillan et al. 2013). The large number of rotational cycles recorded by these light curves allows not only the stellar rotational period to be derived with extreme accuracy but also to detect latitudinal differential rotation by traking spots located at dif ...
Navigating the Night Sky Checklist
... 1. The angular diameter of the Moon is about 0.5 degrees. This means that a star will travel a distance in the sky equivalent to the apparent width of the moon in about 2 minutes. (Stars don't "overtake and pass" the moon, since the moon is moving too. You need to compare to a stationary object like ...
... 1. The angular diameter of the Moon is about 0.5 degrees. This means that a star will travel a distance in the sky equivalent to the apparent width of the moon in about 2 minutes. (Stars don't "overtake and pass" the moon, since the moon is moving too. You need to compare to a stationary object like ...
Neutron Stars
... with the BC (38). For n < 5 the solution decreases monotonically and has a zero at finite value ξ = ξ1 i.e. θ(ξ1 ) = 0 which corresponds to the surface of the star, where p = ρ = 0. Thus we get: ...
... with the BC (38). For n < 5 the solution decreases monotonically and has a zero at finite value ξ = ξ1 i.e. θ(ξ1 ) = 0 which corresponds to the surface of the star, where p = ρ = 0. Thus we get: ...
Neutrinos and Nucleosynthesis
... only gets important for a high ν̄e energy, which is the case during the early times of the cooling phase. This means that the energy limit is depressed to smaller energy differences during the early times of the nucleosynthesis process, meaning the energy difference between νe and ν̄e can be smaller ...
... only gets important for a high ν̄e energy, which is the case during the early times of the cooling phase. This means that the energy limit is depressed to smaller energy differences during the early times of the nucleosynthesis process, meaning the energy difference between νe and ν̄e can be smaller ...
Introduction_to_pulsar_astronomy
... Russel Hulse and Joe Taylor discovered PSR B1913+16, in the constellation Aquila (the Eagle), during a systematic 430-MHz survey of the Galactic plane at Arecibo. ...
... Russel Hulse and Joe Taylor discovered PSR B1913+16, in the constellation Aquila (the Eagle), during a systematic 430-MHz survey of the Galactic plane at Arecibo. ...
21. Galaxy Evolution Agenda The Monty Hall Problem/Paradox 21.1
... nuclei? • We suspect that active galactic nuclei are powered by supermassive black holes that can exceed one billion solar masses. Observations of the rapid variability of active galactic nuclei tells us that their energy output comes from quite a small region, while Doppler shifts of orbiting gas c ...
... nuclei? • We suspect that active galactic nuclei are powered by supermassive black holes that can exceed one billion solar masses. Observations of the rapid variability of active galactic nuclei tells us that their energy output comes from quite a small region, while Doppler shifts of orbiting gas c ...
Characterization and Subtraction of Well
... ghosts caused by the optics in the NIC2 images. The first, evident in most of the targets and in all four filters, is a large ring of diameter 50 that is usually found near the bottom of the field. The ring appears to be a highly defocused reflection of the target star, and its location is very sens ...
... ghosts caused by the optics in the NIC2 images. The first, evident in most of the targets and in all four filters, is a large ring of diameter 50 that is usually found near the bottom of the field. The ring appears to be a highly defocused reflection of the target star, and its location is very sens ...
A cold detached dust envelope around an oxygen-rich Mira
... In order to investigate the geometrical structure of the detached dust envelope, a numerical model by Hashimoto (1995) is employed in the analysis of the infrared data of R Hya. Spectral energy distribution of R Hya is presented in Fig. 3a. Since R Hya is a Mira-type variable star with a large ampli ...
... In order to investigate the geometrical structure of the detached dust envelope, a numerical model by Hashimoto (1995) is employed in the analysis of the infrared data of R Hya. Spectral energy distribution of R Hya is presented in Fig. 3a. Since R Hya is a Mira-type variable star with a large ampli ...
Astronomical Circumstances
... liquid state at temperatures between 0° and 100° C gravitational field. On Earth, objects of great mass also (32° 212° F) at sea level. If a waterrich, Earthlike have great weight, because gravity acts on mass. planet orbits a star within this zone, liquid surface Objects of low mass have low wei ...
... liquid state at temperatures between 0° and 100° C gravitational field. On Earth, objects of great mass also (32° 212° F) at sea level. If a waterrich, Earthlike have great weight, because gravity acts on mass. planet orbits a star within this zone, liquid surface Objects of low mass have low wei ...
Introduction to Galaxies - West Jefferson Local Schools
... Recall, luminosity of stars scales with mass of stars… therefore, luminosity of galaxy scales with number of stars (and thus, mass of stars). Thus, luminosity of galaxy gives mass of galaxy. Going backwards… measure the velocity to “weigh” the galaxy to obtain luminosity. ...
... Recall, luminosity of stars scales with mass of stars… therefore, luminosity of galaxy scales with number of stars (and thus, mass of stars). Thus, luminosity of galaxy gives mass of galaxy. Going backwards… measure the velocity to “weigh” the galaxy to obtain luminosity. ...
- StealthSkater
... End of the Universe (whatever that might be). With all these facts at hand, we're now ready to tackle the first part of the detective story. Let's suppose we wanted to make out own map of a trip to the stars. We will limit ourselves to the 55 light-year radius covered by the detailed star catalogs. ...
... End of the Universe (whatever that might be). With all these facts at hand, we're now ready to tackle the first part of the detective story. Let's suppose we wanted to make out own map of a trip to the stars. We will limit ourselves to the 55 light-year radius covered by the detailed star catalogs. ...
The Witness of the Stars
... Word (the thing spoken, sayings) of God," He asks, "But I say, Have they not heard? Yes, verily." And we may ask, How have they heard? The answer follows--"Their sound went into all the earth and their words (their teaching, message, instruction) unto the ends of the world." What words? What instruc ...
... Word (the thing spoken, sayings) of God," He asks, "But I say, Have they not heard? Yes, verily." And we may ask, How have they heard? The answer follows--"Their sound went into all the earth and their words (their teaching, message, instruction) unto the ends of the world." What words? What instruc ...
Star Formation in the Rosette Complex
... Region. This region comprises the Mon OB1 Cloud (host of NGC 2264 and the Cone Nebula), the Monoceros Loop (NGC 2252), and the Mon OB2 Cloud in which the Rosette is one of the most prominent features (see Figure 2). The catalog name for the Rosette can be somewhat confusing because it is not unique: ...
... Region. This region comprises the Mon OB1 Cloud (host of NGC 2264 and the Cone Nebula), the Monoceros Loop (NGC 2252), and the Mon OB2 Cloud in which the Rosette is one of the most prominent features (see Figure 2). The catalog name for the Rosette can be somewhat confusing because it is not unique: ...
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.