Energetic neutral atoms around HD 209458b
... to account for the larger photon fluxes at the orbital distance of HD 209458b. The stellar wind density and temperature have also been scaled from average solar conditions for our Sun using relations given by Russell et al. (1988). Given the close proximity of HD 209458b to its host star the choice ...
... to account for the larger photon fluxes at the orbital distance of HD 209458b. The stellar wind density and temperature have also been scaled from average solar conditions for our Sun using relations given by Russell et al. (1988). Given the close proximity of HD 209458b to its host star the choice ...
Galaxies Slide Show and Videos
... at the center of galaxies. These are extremely dense quantities of matter in space. They have such strong gravitational pulls that nothing – not even light – is fast enough to escape. 10 Mind-Bending Facts About Black Holes ...
... at the center of galaxies. These are extremely dense quantities of matter in space. They have such strong gravitational pulls that nothing – not even light – is fast enough to escape. 10 Mind-Bending Facts About Black Holes ...
- Lorentz Center
... This motivates the “standard story” of unstable C ignition in the core from a single degenerate H donor. . . . • The density must >109 gr/cm3 in the cold (~108 K) core to trigger C burning. This requires M>1.33M and accumulation of mass during accretion. . . • Challenge is the outcome of H and He b ...
... This motivates the “standard story” of unstable C ignition in the core from a single degenerate H donor. . . . • The density must >109 gr/cm3 in the cold (~108 K) core to trigger C burning. This requires M>1.33M and accumulation of mass during accretion. . . • Challenge is the outcome of H and He b ...
Problem Set 2 for Astro 322 Read chapter 24.2. (Some of this
... that LD = 2πh2R I(R = 0). For the Milky Way, 1.5 × 1010 L = 2πh2R I(R = 0), and I(R) = I(R = 0) exp[−R/hR ]. We find I(R = 0) = LD /(2πh2R ) = 1.5 × 1010 L /(2π(4000pc)2 ) = 149 L pc−2 . Then I(R = 8kpc) = I(R = 0)exp(−8/4) = 20.2 L pc−2 . We note that this M/LV ratio is integrated over all z, t ...
... that LD = 2πh2R I(R = 0). For the Milky Way, 1.5 × 1010 L = 2πh2R I(R = 0), and I(R) = I(R = 0) exp[−R/hR ]. We find I(R = 0) = LD /(2πh2R ) = 1.5 × 1010 L /(2π(4000pc)2 ) = 149 L pc−2 . Then I(R = 8kpc) = I(R = 0)exp(−8/4) = 20.2 L pc−2 . We note that this M/LV ratio is integrated over all z, t ...
Sporadic Mass Ejection in Red Supergiants
... to be ejected on average every r/\JC years. This time scale is rather small (rovlO days) for relatively large mass loss rates, i.e., rov1Q- 5 M 0 yr- 1. Note that while an element needs to be ejected every 10 days, there will be many more elements moving with a velocity less than the escape speed. S ...
... to be ejected on average every r/\JC years. This time scale is rather small (rovlO days) for relatively large mass loss rates, i.e., rov1Q- 5 M 0 yr- 1. Note that while an element needs to be ejected every 10 days, there will be many more elements moving with a velocity less than the escape speed. S ...
The IMF of intermediate-mass stars in young star clusters
... the full mass range 1-80M , we get a value of 2.32 ± 0.3. Reliable MF slope and cluster age for a number of young star clusters and associations located in LMCs have been determined using both ground-based telescopes and HST, see the compilation of MF slopes by Sagar (2000). We have updated this co ...
... the full mass range 1-80M , we get a value of 2.32 ± 0.3. Reliable MF slope and cluster age for a number of young star clusters and associations located in LMCs have been determined using both ground-based telescopes and HST, see the compilation of MF slopes by Sagar (2000). We have updated this co ...
Ten Years Of XMM-Newton: Scientific Achievements And Future Prospects Norbert Schartel
... • Distance to globular clusters is well known ...
... • Distance to globular clusters is well known ...
Core Collapse Supernovae and Neutron Star Kicks, a Primer David
... observed with periods of ~5-12s (much slower than radio pulsars) and only 11 sources have been detected to date (Gaensler 2004). Since so few have been detected, it is extremely difficult to draw any conclusions about the overall properties of the populations. Ideally, the supernova remnants associa ...
... observed with periods of ~5-12s (much slower than radio pulsars) and only 11 sources have been detected to date (Gaensler 2004). Since so few have been detected, it is extremely difficult to draw any conclusions about the overall properties of the populations. Ideally, the supernova remnants associa ...
feps_jan_2007_aas - The Formation & Evolution of Planetary
... stars with ages from 3 Myr to 3 Gyr in order to construct spectral energy distributions (SEDs) from 3-160 microns, as well as obtain high resolution midinfrared spectra. The SEDs yield constraints on the geometric distribution and mass of dust while the spectra enable a search for emission from gas ...
... stars with ages from 3 Myr to 3 Gyr in order to construct spectral energy distributions (SEDs) from 3-160 microns, as well as obtain high resolution midinfrared spectra. The SEDs yield constraints on the geometric distribution and mass of dust while the spectra enable a search for emission from gas ...
ppt - CIERA - Northwestern
... masses up to and beyond 106 Msun and R1/2 ~ 2-5 pc. Densest stellar cluster--an extreme of star formation. SSCs cluster to make “starburst clumps” where SSC-SSC interactions are possible and which drive galactic winds. SSCs contain a full range of intermediate-high mass stars. Central stellar densit ...
... masses up to and beyond 106 Msun and R1/2 ~ 2-5 pc. Densest stellar cluster--an extreme of star formation. SSCs cluster to make “starburst clumps” where SSC-SSC interactions are possible and which drive galactic winds. SSCs contain a full range of intermediate-high mass stars. Central stellar densit ...
Refined stellar, orbital and planetary parameters of the eccentric
... complete transit light curves, and three partial events. One of these follow-up light curves (2007 April 21) was reported in the discovery paper. All of our individual high precision follow-up photometry data are plotted in Fig. 2, along with our best-fitting transit lightcurve model. The folded and ...
... complete transit light curves, and three partial events. One of these follow-up light curves (2007 April 21) was reported in the discovery paper. All of our individual high precision follow-up photometry data are plotted in Fig. 2, along with our best-fitting transit lightcurve model. The folded and ...
The Evolutionary Status of Be Stars in Clusters and in the Galactic
... equator, and hence the luminosity class also depends on the inclination angle. Taking into account both effects, a rapidly rotating star seen pole-on would present high luminosity and gravity, and hence would be a class V star at the top of the main sequence. If seen equator-on, it would present low ...
... equator, and hence the luminosity class also depends on the inclination angle. Taking into account both effects, a rapidly rotating star seen pole-on would present high luminosity and gravity, and hence would be a class V star at the top of the main sequence. If seen equator-on, it would present low ...
Clusters - El Camino College
... Forming Clusters When giant clouds of dust and gas form, the dust becomes thick enough to block visible and ultraviolet light (short wavelengths) from stars outside the cloud. Therefore, clouds cannot cool except by radiating away energy in other forms, such as infrared and radio radiation (long wav ...
... Forming Clusters When giant clouds of dust and gas form, the dust becomes thick enough to block visible and ultraviolet light (short wavelengths) from stars outside the cloud. Therefore, clouds cannot cool except by radiating away energy in other forms, such as infrared and radio radiation (long wav ...
UvA-DARE (Digital Academic Repository)
... Figuree 1.3: Conservative evolutionary scenario for the formation of a Be/X-ray binary, out of a close pairr of early B stars with masses of 13.0 M 0 and 6.5 M 0 . The numbers indicate mass (M 0 ). After the endd of the mass transfer, the Be star presumably has a circumstellar disc or shell of matte ...
... Figuree 1.3: Conservative evolutionary scenario for the formation of a Be/X-ray binary, out of a close pairr of early B stars with masses of 13.0 M 0 and 6.5 M 0 . The numbers indicate mass (M 0 ). After the endd of the mass transfer, the Be star presumably has a circumstellar disc or shell of matte ...
A binary merger origin for inflated hot Jupiter planets
... large size of some exoplanets, which has been termed the “radius anomaly” of hot Jupiters (Bodenheimer et al. 2001; Guillot et al. 2006). Several mechanisms have been invoked to account for the radius anomaly, such as diffusion of stellar irradiation into the planet interior, enhanced opacities, ineffi ...
... large size of some exoplanets, which has been termed the “radius anomaly” of hot Jupiters (Bodenheimer et al. 2001; Guillot et al. 2006). Several mechanisms have been invoked to account for the radius anomaly, such as diffusion of stellar irradiation into the planet interior, enhanced opacities, ineffi ...
2P10.pdf
... The scientific goals of the Gaia mission require complementary astrometry, photometry and radial velocity data. After five years scanning the entire sky, Gaia will have performed measurements with broad (BBP), and medium (MBP) bands, and white light (G magnitude). The main goal of the photometry is ...
... The scientific goals of the Gaia mission require complementary astrometry, photometry and radial velocity data. After five years scanning the entire sky, Gaia will have performed measurements with broad (BBP), and medium (MBP) bands, and white light (G magnitude). The main goal of the photometry is ...
C, N, O abundances and carbon isotope ratios in evolved stars of
... we neglected NGC 6253 2508 in the analysis. All stars observed in NGC 6253 belong to the red clump of the cluster (see Fig. 2). In this work as well as in other papers of this series (Mikolaitis et al. 2010, 2011a,b), the atlas models with overshooting (Kurucz 1993) and a computing code by Gratton ( ...
... we neglected NGC 6253 2508 in the analysis. All stars observed in NGC 6253 belong to the red clump of the cluster (see Fig. 2). In this work as well as in other papers of this series (Mikolaitis et al. 2010, 2011a,b), the atlas models with overshooting (Kurucz 1993) and a computing code by Gratton ( ...
Star Life Cycle
... break down these three according to a slight variation in shape between each type of galaxy in each category. For the "E" or 5)_________________galaxies, he used the amount of flattening or 6)_____________, from E0( E zero) to E5, to put the galaxies into smaller groups. For the "S" or 7)___________ ...
... break down these three according to a slight variation in shape between each type of galaxy in each category. For the "E" or 5)_________________galaxies, he used the amount of flattening or 6)_____________, from E0( E zero) to E5, to put the galaxies into smaller groups. For the "S" or 7)___________ ...
Stellar Populations For many modern applications, one is not
... The above analytic solutions are only useful for guidance. To compare with observations, predictions must be made in specific bandpasses, or for specific absorption lines. This requires numerical calculations which include 1) sets of stellar isochrones, detailing the precise number of stars at any p ...
... The above analytic solutions are only useful for guidance. To compare with observations, predictions must be made in specific bandpasses, or for specific absorption lines. This requires numerical calculations which include 1) sets of stellar isochrones, detailing the precise number of stars at any p ...
Introduc on to the Fundamental Astrophysics Course
... Being more specific … Star Forma)on • Star forma)on is the process by which dense regions within molecular clouds in interstellar space, commonly referred to as "stellar nurseries", collapse into spheres o ...
... Being more specific … Star Forma)on • Star forma)on is the process by which dense regions within molecular clouds in interstellar space, commonly referred to as "stellar nurseries", collapse into spheres o ...
Stellar Populations Science
... increasing the number of available galaxies by an order of magnitude, covering a wide range of morphological types, masses, and environments – Greater sensitivity and resolution allows high resolution spectroscopic analysis of TRGB stars out to ~4 Mpc, making it possible to study the detailed chemis ...
... increasing the number of available galaxies by an order of magnitude, covering a wide range of morphological types, masses, and environments – Greater sensitivity and resolution allows high resolution spectroscopic analysis of TRGB stars out to ~4 Mpc, making it possible to study the detailed chemis ...
WASP-120b, WASP-122b and WASP-123b: Three newly discovered
... a moderately bright (V = 11.0) F5 star. The effective temperature of WASP-120 places it in the lithium gap (Böhm-Vitense 2004), so we cannot estimate the age of this star based on the lithium abundance. Using the star’s Tycho B−V colour and rotation period from its V sin i and radius from our MCMC ...
... a moderately bright (V = 11.0) F5 star. The effective temperature of WASP-120 places it in the lithium gap (Böhm-Vitense 2004), so we cannot estimate the age of this star based on the lithium abundance. Using the star’s Tycho B−V colour and rotation period from its V sin i and radius from our MCMC ...
File - Astronomy Home
... figure can be seen high in the sky starting near the end of summer and continuing through autumn if you live in the Northern Hemisphere. If you are below the Equator, look for Pegasus in late winter and through spring. When looking at the image, it is difficult to see the figure as a horse. That is ...
... figure can be seen high in the sky starting near the end of summer and continuing through autumn if you live in the Northern Hemisphere. If you are below the Equator, look for Pegasus in late winter and through spring. When looking at the image, it is difficult to see the figure as a horse. That is ...
A new class of rapidly pulsating star
... amplitude waning due to mode beating. We would thus expect to identify spurious modes with frequencies close to those truly present in the observations, were the data from the two data sets combined. A sample light curve is shown in Fig. 1. The variable amplitude of the pulsations is clearly visible ...
... amplitude waning due to mode beating. We would thus expect to identify spurious modes with frequencies close to those truly present in the observations, were the data from the two data sets combined. A sample light curve is shown in Fig. 1. The variable amplitude of the pulsations is clearly visible ...
GRB 021004: A Possible Shell Nebula around a Wolf
... black hole surrounded by an accretion disk wind [14]. While it is now generally accepted that some long-duration GRBs are associated with the deaths of massive stars, considerable uncertainty remains as to what the precise nature of the progenitor star is. Theories of stellar evolution suggest that ...
... black hole surrounded by an accretion disk wind [14]. While it is now generally accepted that some long-duration GRBs are associated with the deaths of massive stars, considerable uncertainty remains as to what the precise nature of the progenitor star is. Theories of stellar evolution suggest that ...
Planetary nebula
A planetary nebula, often abbreviated as PN or plural PNe, is a kind of emission nebula consisting of an expanding glowing shell of ionized gas ejected from old red giant stars late in their lives. The word ""nebula"" is Latin for mist or cloud and the term ""planetary nebula"" is a misnomer that originated in the 1780s with astronomer William Herschel because when viewed through his telescope, these objects appeared to him to resemble the rounded shapes of planets. Herschel's name for these objects was popularly adopted and has not been changed. They are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years.A mechanism for formation of most planetary nebulae is thought to be the following: at the end of the star's life, during the red giant phase, the outer layers of the star are expelled by strong stellar winds. Eventually, after most of the red giant's atmosphere is dissipated, the exposed hot, luminous core emits ultraviolet radiation to ionize the ejected outer layers of the star. Absorbed ultraviolet light energises the shell of nebulous gas around the central star, appearing as a bright coloured planetary nebula at several discrete visible wavelengths.Planetary nebulae may play a crucial role in the chemical evolution of the Milky Way, returning material to the interstellar medium from stars where elements, the products of nucleosynthesis (such as carbon, nitrogen, oxygen and neon), have been created. Planetary nebulae are also observed in more distant galaxies, yielding useful information about their chemical abundances.In recent years, Hubble Space Telescope images have revealed many planetary nebulae to have extremely complex and varied morphologies. About one-fifth are roughly spherical, but the majority are not spherically symmetric. The mechanisms which produce such a wide variety of shapes and features are not yet well understood, but binary central stars, stellar winds and magnetic fields may play a role.