![Wind-Blown Bubbles around Evolved Stars](http://s1.studyres.com/store/data/001495550_1-1a9f709a019220722f9a28d4f871fae9-300x300.png)
Wind-Blown Bubbles around Evolved Stars
... physical processes can be included.2 The first, spherically symmetric, numerical studies included radiative cooling and were able to follow the transition between the initial fully adiabatic stage to the stage where the swept-up interstellar medium cools radiatively (Falle, 1975). Subsequent numeric ...
... physical processes can be included.2 The first, spherically symmetric, numerical studies included radiative cooling and were able to follow the transition between the initial fully adiabatic stage to the stage where the swept-up interstellar medium cools radiatively (Falle, 1975). Subsequent numeric ...
$doc.title
... We investigate the effect of the magnetic fields of M dwarf (dM) stars on potentially habitable Earth-like planets. These fields can reduce the size of planetary magnetospheres to such an extent that a significant fraction of the planet’s atmosphere may be exposed to erosion by the stellar wind. We ...
... We investigate the effect of the magnetic fields of M dwarf (dM) stars on potentially habitable Earth-like planets. These fields can reduce the size of planetary magnetospheres to such an extent that a significant fraction of the planet’s atmosphere may be exposed to erosion by the stellar wind. We ...
16.1 A Little History
... ble explanations, the most intriguing possibility is that stars more massive than ∼ 17M may collapse ‘quietly’ to form black holes and either very faint supernovae or no supernova at all. ...
... ble explanations, the most intriguing possibility is that stars more massive than ∼ 17M may collapse ‘quietly’ to form black holes and either very faint supernovae or no supernova at all. ...
When Extrasolar Planets Transit Their Parent Stars
... among members of double- or multiple-star systems. Grazing eclipses in binary systems can result in transit-like signals with depths and durations that resemble planetary ones (Brown, 2003), and this effect is especially pronounced for candidate transits having depths greater than 1%. (For equal-siz ...
... among members of double- or multiple-star systems. Grazing eclipses in binary systems can result in transit-like signals with depths and durations that resemble planetary ones (Brown, 2003), and this effect is especially pronounced for candidate transits having depths greater than 1%. (For equal-siz ...
Physics of Galaxies 2016 Exercises with solutions – Batch II
... forms new stars with a constant SFR. Individual star clusters are usually treated as single-age stellar populations, so the model to compare to is the red line in Figure 2. As seen, an Hα equivalent width of EW(Hα)=960 Å is reached at an age of log10 Age ≈ 6.5–6.6, i.e. Age ≈ 3–4 Myr. Should EW(Hα) ...
... forms new stars with a constant SFR. Individual star clusters are usually treated as single-age stellar populations, so the model to compare to is the red line in Figure 2. As seen, an Hα equivalent width of EW(Hα)=960 Å is reached at an age of log10 Age ≈ 6.5–6.6, i.e. Age ≈ 3–4 Myr. Should EW(Hα) ...
Article PDF - IOPscience
... ⫺0.3 arcmin or 64⫺20 pc to the east (the uncertainties have been determined by a bootstrap resampling of the position of the BP stars within rhb). The spectroscopic survey of Ibata et al. (2006) and Martin et al. (2007) has also revealed the presence of two distinct components in this galaxy from th ...
... ⫺0.3 arcmin or 64⫺20 pc to the east (the uncertainties have been determined by a bootstrap resampling of the position of the BP stars within rhb). The spectroscopic survey of Ibata et al. (2006) and Martin et al. (2007) has also revealed the presence of two distinct components in this galaxy from th ...
Infrared spectroscopy of exoplanets: observational constraints
... and resolving power The infrared spectrum of an exoplanet is composed of two main components: the reflected/scattered stellar flux, which peaks in the UV, visible or near-infrared range (depending on the spectral type of the host star), and the thermal emission which dominates at longer wavelengths. I ...
... and resolving power The infrared spectrum of an exoplanet is composed of two main components: the reflected/scattered stellar flux, which peaks in the UV, visible or near-infrared range (depending on the spectral type of the host star), and the thermal emission which dominates at longer wavelengths. I ...
Finding What`s Up There Part1
... Celestial charts are maps of the sky drawn to different levels of detail. They can include stars from magnitude 5 to magnitude11. They have advantages and disadvantages. Magnitude 5 or 6 charts show a bigger portion of the sky than more detailed charts and make navigating the sky easier. Magnitude 9 ...
... Celestial charts are maps of the sky drawn to different levels of detail. They can include stars from magnitude 5 to magnitude11. They have advantages and disadvantages. Magnitude 5 or 6 charts show a bigger portion of the sky than more detailed charts and make navigating the sky easier. Magnitude 9 ...
Observational Confirmation of a Link Between Common Envelope
... the availability of the nebular lines allows us to internally calibrate each science spectrum. This includes the early spectra which did not have arc spectra taken consecutively. We find an average and standard deviation for all spectral lines across all spectra (removing those with no consecutive a ...
... the availability of the nebular lines allows us to internally calibrate each science spectrum. This includes the early spectra which did not have arc spectra taken consecutively. We find an average and standard deviation for all spectral lines across all spectra (removing those with no consecutive a ...
Section 2: Applet Walkthrough
... As we have seen, in the Star Selection box (lower left) you can choose which stars you want plotted on the diagram. There is also a Find feature that can be used to locate a specific star in the database of stars already in the applet (25 brightest stars and 34 nearest stars) or a userdefined star. ...
... As we have seen, in the Star Selection box (lower left) you can choose which stars you want plotted on the diagram. There is also a Find feature that can be used to locate a specific star in the database of stars already in the applet (25 brightest stars and 34 nearest stars) or a userdefined star. ...
Ch. 19 - Astro1010
... Often as a large star ages much of the fuel is used up and deposited as ‘ash’ in the iron core. The inward pressure on the iron core is enormous, due to the high mass of the star. As the core continues to become more and more dense, the protons react with one another to become neutrons + a flood of ...
... Often as a large star ages much of the fuel is used up and deposited as ‘ash’ in the iron core. The inward pressure on the iron core is enormous, due to the high mass of the star. As the core continues to become more and more dense, the protons react with one another to become neutrons + a flood of ...
The accretion properties of the intermediate mass Herbig Ae/Be stars
... Accretion rate correlates with mass But: different slope Ae and Be objects Occurs at similar mass as other such findings Vink+ 2002 (see also Muzerolle+ 2004, Grady+ 2010, Oudmaijer+ 2011, Alecian+ 2013, Cauley & Johns-Krull 2015) ...
... Accretion rate correlates with mass But: different slope Ae and Be objects Occurs at similar mass as other such findings Vink+ 2002 (see also Muzerolle+ 2004, Grady+ 2010, Oudmaijer+ 2011, Alecian+ 2013, Cauley & Johns-Krull 2015) ...
CoRoT pictures transiting exoplanets
... night side would be frozen, with a temperature difference between both hemispheres reaching 2400K [15]. The composition of CoRoT-7 b is likely dominated by silicates, that are eroded into a thin atmosphere of rocky vapor due to the large surface temperatures [15]. Today, thanks to Kepler and ground- ...
... night side would be frozen, with a temperature difference between both hemispheres reaching 2400K [15]. The composition of CoRoT-7 b is likely dominated by silicates, that are eroded into a thin atmosphere of rocky vapor due to the large surface temperatures [15]. Today, thanks to Kepler and ground- ...
A Second Luminous Blue Variable in the Quintuplet Cluster
... to second order by the eective temperature. Dierent velocity elds and transition zones between photosphere and wind can easily mask a factor of ve change in Si abundance (producing similar Si ii 1.7 m emission line strengths and pro les), even if the stars have the same eective temperature, ra ...
... to second order by the eective temperature. Dierent velocity elds and transition zones between photosphere and wind can easily mask a factor of ve change in Si abundance (producing similar Si ii 1.7 m emission line strengths and pro les), even if the stars have the same eective temperature, ra ...
Spectroscopic Binaries - Thüringer Landessternwarte Tautenburg
... (valid for weak lines) - self-similar local profile shape - linear addition of blends Determination of P = linear deconvolution problem search for the least squares solution Improvements: - recover the individual line strengths - use line lists for multi-component atmospheres ...
... (valid for weak lines) - self-similar local profile shape - linear addition of blends Determination of P = linear deconvolution problem search for the least squares solution Improvements: - recover the individual line strengths - use line lists for multi-component atmospheres ...
observation reports
... 80-100 stars in the field at high power. 23:05 (00:05) Time to take a break from the ETX, for a naked-eye look at the sky. The Milky Way was visible all the way from Perseus to Scutum, and very clear in Cygnus. I spotted two bright Perseids in ten minutes, and by now Pegasus was well-placed enough f ...
... 80-100 stars in the field at high power. 23:05 (00:05) Time to take a break from the ETX, for a naked-eye look at the sky. The Milky Way was visible all the way from Perseus to Scutum, and very clear in Cygnus. I spotted two bright Perseids in ten minutes, and by now Pegasus was well-placed enough f ...
ISOLATED, MASSIVE SUPERGIANTS NEAR THE GALACTIC
... with the radio H ii region H2 and a newly identified star that we refer to as CXOGC J174516.1290315. The infrared spectra of both stars exhibit very strong Br and He i lines and resemble those of massive supergiants that have evolved off of the main sequence but not yet reached the Wolf-Rayet phas ...
... with the radio H ii region H2 and a newly identified star that we refer to as CXOGC J174516.1290315. The infrared spectra of both stars exhibit very strong Br and He i lines and resemble those of massive supergiants that have evolved off of the main sequence but not yet reached the Wolf-Rayet phas ...
FIVE NEW TRANSITS OF THE SUPER
... More recently, Harrington et al. (2007) found that the 8 m brightness temperature of HD 149026b exceeds its expected blackbody temperature, even if the planet is assumed to absorb all of the incident stellar radiation. In this sense the planet is anomalously hot. The high temperature may result fro ...
... More recently, Harrington et al. (2007) found that the 8 m brightness temperature of HD 149026b exceeds its expected blackbody temperature, even if the planet is assumed to absorb all of the incident stellar radiation. In this sense the planet is anomalously hot. The high temperature may result fro ...
sections 4-6 instructor notes
... planetary satellites. Such devices are somewhat limited in their spectral coverage by the mask employed (usually they are restricted to spectral types F or later), but are nevertheless easier to use and faster than photographic plates, reach fainter stars, and have high internal accuracy. Typical un ...
... planetary satellites. Such devices are somewhat limited in their spectral coverage by the mask employed (usually they are restricted to spectral types F or later), but are nevertheless easier to use and faster than photographic plates, reach fainter stars, and have high internal accuracy. Typical un ...
Age patterns in a sample of spiral galaxies
... The study of the SFH and SFR provides vital information regarding the evolutionary properties of galaxies and the physical processes which drive their evolution. SF can vary across the different types of galaxies depending on factors such as gas content, mass, or environment [15], even for the same ...
... The study of the SFH and SFR provides vital information regarding the evolutionary properties of galaxies and the physical processes which drive their evolution. SF can vary across the different types of galaxies depending on factors such as gas content, mass, or environment [15], even for the same ...
Radiation vs. Gas Pressure, the Stellar Mass
... To me, there are two key conclusions from the above: 1. Simple scalings from stellar structure imply that stars near or above 100 M⊙ must inevitably be near the Eddington limit, with radiation pressure dominating over gas pressure in the stellar envelope. 2. However, the Eddington limit itself acts ...
... To me, there are two key conclusions from the above: 1. Simple scalings from stellar structure imply that stars near or above 100 M⊙ must inevitably be near the Eddington limit, with radiation pressure dominating over gas pressure in the stellar envelope. 2. However, the Eddington limit itself acts ...
Non-Thermal Radio Emission from Binary Systems
... 5 GHz with a radio telescope with a typical minimum flux density of 1 mJy: the quiet Sun: the slowly varying component: the very strong solar radio bursts: ...
... 5 GHz with a radio telescope with a typical minimum flux density of 1 mJy: the quiet Sun: the slowly varying component: the very strong solar radio bursts: ...
Molecular Cooling Rates (Neufeld, Lepp and Melnick 1995)
... Canonical picture • AGB stars are intermediate mass stars which are burning H or He in a shell • Stellar radius ~ 1 a.u. • Stellar luminosity ~ 104 L • Photospheric temperature ~ 2000 – 3000 K • Long period pulsational variables (P ~ 1 yr) • Outflowing envelopes (v ~ 10 km/s) driven by radiation p ...
... Canonical picture • AGB stars are intermediate mass stars which are burning H or He in a shell • Stellar radius ~ 1 a.u. • Stellar luminosity ~ 104 L • Photospheric temperature ~ 2000 – 3000 K • Long period pulsational variables (P ~ 1 yr) • Outflowing envelopes (v ~ 10 km/s) driven by radiation p ...
NExSS Biosignatures Workshop O2 Lessons
... the coevolution of life with the early Earth’s environment, and how the interplay of sources and sinks in the planetary environment may have resulted in suppression of O2 release into the atmosphere for several billion years, a false negative for biologically generated O2. False positives may also b ...
... the coevolution of life with the early Earth’s environment, and how the interplay of sources and sinks in the planetary environment may have resulted in suppression of O2 release into the atmosphere for several billion years, a false negative for biologically generated O2. False positives may also b ...
CH15.AST1001.S15.EDS
... • Cloud cores collapse into protostars • the whole star formation process begins • the molecular cloud is eroded away by radiation from newly formed stars ...
... • Cloud cores collapse into protostars • the whole star formation process begins • the molecular cloud is eroded away by radiation from newly formed stars ...
Planetary nebula
![](https://commons.wikimedia.org/wiki/Special:FilePath/NGC6543.jpg?width=300)
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.