The Lost Zodiac - Interactive Stars
... We are often linked to one another through the myths which rule our lives and through our inner quests for wholeness. Our myth may resonate with that of another person's because it describes a similar journey of discovery. Sometimes, our 'story' may be part of the same mythic pattern, or cycle of st ...
... We are often linked to one another through the myths which rule our lives and through our inner quests for wholeness. Our myth may resonate with that of another person's because it describes a similar journey of discovery. Sometimes, our 'story' may be part of the same mythic pattern, or cycle of st ...
MS-SCI-PS-Unit 4 -- Chapter 15- Stars, Galaxies
... atmosphere. To detect these wavelengths, astronomers have placed telescopes in space. Some space telescopes are designed to detect visible light or infrared radiation, since Earth's atmosphere also interferes with the transmission of these forms of radiation. The Hubble Space Telescope is a reflecti ...
... atmosphere. To detect these wavelengths, astronomers have placed telescopes in space. Some space telescopes are designed to detect visible light or infrared radiation, since Earth's atmosphere also interferes with the transmission of these forms of radiation. The Hubble Space Telescope is a reflecti ...
A radio pulsing white dwarf binary star
... White dwarfs are compact stars, similar in size to Earth but ∼ 200,000 times more massive1 . Isolated white dwarfs emit most of their power from ultraviolet to near-infrared wavelengths, but when in close orbits with less dense stars, white dwarfs can strip material from their companions, and the re ...
... White dwarfs are compact stars, similar in size to Earth but ∼ 200,000 times more massive1 . Isolated white dwarfs emit most of their power from ultraviolet to near-infrared wavelengths, but when in close orbits with less dense stars, white dwarfs can strip material from their companions, and the re ...
On the possibility of a helium white dwarf donor in the presumed
... Abstract. 2S 0918–549 is a low-mass X-ray binary (LMXB) with a low optical to X-ray flux ratio. Probably it is an ultracompact binary with an orbital period shorter than 60 min. Such binaries cannot harbor hydrogen rich donor stars. As with other (sometimes confirmed) ultracompact LMXBs, 2S 0918–549 ...
... Abstract. 2S 0918–549 is a low-mass X-ray binary (LMXB) with a low optical to X-ray flux ratio. Probably it is an ultracompact binary with an orbital period shorter than 60 min. Such binaries cannot harbor hydrogen rich donor stars. As with other (sometimes confirmed) ultracompact LMXBs, 2S 0918–549 ...
Magnetars origin and progenitors with enhanced rotation'
... We present population synthesis calculations of binary systems. Our goal is to estimate the number of neutron stars originated from progenitors with enhanced rotation, as such compact objects can be expected to have large magnetic fields, i.e. they can be magnetars. ...
... We present population synthesis calculations of binary systems. Our goal is to estimate the number of neutron stars originated from progenitors with enhanced rotation, as such compact objects can be expected to have large magnetic fields, i.e. they can be magnetars. ...
Magnetic susceptibility, magnetization, magnetic moment and
... We calculate emissivity maps for important nebular emission lines. Their intensities are used to derive the chemical abundance of oxygen by the so-called T e − and R23 −methods. Some disagreements are found between oxygen abundances calculated with these methods and the ones coming from the ChDSs. W ...
... We calculate emissivity maps for important nebular emission lines. Their intensities are used to derive the chemical abundance of oxygen by the so-called T e − and R23 −methods. Some disagreements are found between oxygen abundances calculated with these methods and the ones coming from the ChDSs. W ...
THE KEPLER CLUSTER STUDY: STELLAR ROTATION IN NGC 6811
... process, attempts are made to remove signals in the data from pointing drifts, focus changes, and thermal variations. As described in the Kepler Data Release Notes (Van Cleve et al. 2010), the pipeline is still under development and is primarily intended to optimize the search for planetary transits ...
... process, attempts are made to remove signals in the data from pointing drifts, focus changes, and thermal variations. As described in the Kepler Data Release Notes (Van Cleve et al. 2010), the pipeline is still under development and is primarily intended to optimize the search for planetary transits ...
A Reservoir of Ionized Gas in the Galactic Halo to Sustain Star
... absorption at similar high velocities, demonstrating their multiphase nature (13). The velocity sky-distribution of the O VI, Si III, and H I HVCs are also alike (12–14), and the sky-distribution of the iHVCs seen toward the AGNs and stars is moreover remarkably similar considering our better sampl ...
... absorption at similar high velocities, demonstrating their multiphase nature (13). The velocity sky-distribution of the O VI, Si III, and H I HVCs are also alike (12–14), and the sky-distribution of the iHVCs seen toward the AGNs and stars is moreover remarkably similar considering our better sampl ...
HST observations of the field star population in the Large Magellanic
... Demarque & King 1987) with Y = 0.3 and a range of metallicities and ages. We based our choice of metallicities on the results of Olszewski et al. (1991), who plot [Fe/H] versus age for 29 LMC clusters with metallicities determined from spectra of a total of 80 individual stars. The value Z = 0.01 is ...
... Demarque & King 1987) with Y = 0.3 and a range of metallicities and ages. We based our choice of metallicities on the results of Olszewski et al. (1991), who plot [Fe/H] versus age for 29 LMC clusters with metallicities determined from spectra of a total of 80 individual stars. The value Z = 0.01 is ...
A radio-pulsing white dwarf binary star
... White dwarfs are not born spinning rapidly24 , and a prior stage of accretion-driven spin-up is required. Depending upon the distance at which the accreting material coupled to the white dwarf’s magnetic field, between 0.002 M and 0.015 M of matter are required to reach PS = 1.95 min. For an accre ...
... White dwarfs are not born spinning rapidly24 , and a prior stage of accretion-driven spin-up is required. Depending upon the distance at which the accreting material coupled to the white dwarf’s magnetic field, between 0.002 M and 0.015 M of matter are required to reach PS = 1.95 min. For an accre ...
February - Saguaro Astronomy Club
... The telescope is controlled by a scaled down version of the same Meade Autostar that controls the larger ETX models. By scaled down I mean the database is noticeably smaller although it still has objects way to faint to be seen in this telescope, i.e. the Horsehead. The keypad is also smaller elimin ...
... The telescope is controlled by a scaled down version of the same Meade Autostar that controls the larger ETX models. By scaled down I mean the database is noticeably smaller although it still has objects way to faint to be seen in this telescope, i.e. the Horsehead. The keypad is also smaller elimin ...
View/Open - NuSpace Home - National University of Science and
... al. 1998) – let us call the mass function exhibited by cores the Core Mass Function (CoMF). Sure, something universal and subtle must be at work giving rise to such important prominent characteristic of stellar systems on the different scales. It is only natural to ask the important and perdurable q ...
... al. 1998) – let us call the mass function exhibited by cores the Core Mass Function (CoMF). Sure, something universal and subtle must be at work giving rise to such important prominent characteristic of stellar systems on the different scales. It is only natural to ask the important and perdurable q ...
Introduction to VLTI and first scientific results
... Summary: VINCI interferometry revealed that η Car's optically thick, non-spherical wind region has a size of ~ 5 mas (axis ratio 1.2, PA 130°) (van Boekel et al. 2003). This non-spherical wind can be explained by models for line-driven winds from luminous hot stars rotating near their critical spee ...
... Summary: VINCI interferometry revealed that η Car's optically thick, non-spherical wind region has a size of ~ 5 mas (axis ratio 1.2, PA 130°) (van Boekel et al. 2003). This non-spherical wind can be explained by models for line-driven winds from luminous hot stars rotating near their critical spee ...
Written by G. Jeffrey Taylor
... ome presolar grains found in meteorites have isotopic compositions of silicon, carbon, and other elements predicted for formation in material flowing from asymptotic giant branch starts, nicknamed AGB stars. Stars with masses not too much different from the Sun reach this stage after using up all th ...
... ome presolar grains found in meteorites have isotopic compositions of silicon, carbon, and other elements predicted for formation in material flowing from asymptotic giant branch starts, nicknamed AGB stars. Stars with masses not too much different from the Sun reach this stage after using up all th ...
docx - UT Austin (Astronomy)
... Detecting Exoplanets with the Transit Method 10) In the following figure, four different exoplanet systems are shown on the left, and four different graphs of brightness vs. time are shown on the right. Match each exoplanet system with the graph that best represents the brightness we would observe ...
... Detecting Exoplanets with the Transit Method 10) In the following figure, four different exoplanet systems are shown on the left, and four different graphs of brightness vs. time are shown on the right. Match each exoplanet system with the graph that best represents the brightness we would observe ...
Formation and composition of planets around very low mass stars
... ∼ 1M⊕ , although some can be as massive as ∼ 1.5M⊕ ), and planets totally devoid of water are all less massive than 1M⊕ , and even lower than 0.4M⊕ if one does not consider the massive disks. This can be easily understood as an effect of migration: more massive planets migrate from further out and t ...
... ∼ 1M⊕ , although some can be as massive as ∼ 1.5M⊕ ), and planets totally devoid of water are all less massive than 1M⊕ , and even lower than 0.4M⊕ if one does not consider the massive disks. This can be easily understood as an effect of migration: more massive planets migrate from further out and t ...
Optical variability of the B-type star HD 105382: Pulsation or rotation?
... Different opinions about the Be character of HD 105382 are present in the literature. The star was classified as a Be star by Hiltner et al. (1969), who found clear emission in the Balmer lines. On the other hand, Dachs et al. (1981) took spectrograms in 1978 and concluded that the star should be de ...
... Different opinions about the Be character of HD 105382 are present in the literature. The star was classified as a Be star by Hiltner et al. (1969), who found clear emission in the Balmer lines. On the other hand, Dachs et al. (1981) took spectrograms in 1978 and concluded that the star should be de ...
PDF file
... 3) Bound vs. unbound clusters. While many young stars are born in groups and clusters, most disperse rapidly; few clusters remain bound over timescales > 10 Myr. The conditions under which bound clusters are produced are not clear. Studies of older, widely-spread low-mass stars around young cluster ...
... 3) Bound vs. unbound clusters. While many young stars are born in groups and clusters, most disperse rapidly; few clusters remain bound over timescales > 10 Myr. The conditions under which bound clusters are produced are not clear. Studies of older, widely-spread low-mass stars around young cluster ...
Session 3 – The Big Bang Pt.2
... The problem is the Big Bang would create a completely equal and smooth universe and distribution of mass/energy Dr. Danny Faulkner : "The cosmology popular today supposes that early in the universe large clouds of gas began to form. These clouds were millions of light years across and slowly conden ...
... The problem is the Big Bang would create a completely equal and smooth universe and distribution of mass/energy Dr. Danny Faulkner : "The cosmology popular today supposes that early in the universe large clouds of gas began to form. These clouds were millions of light years across and slowly conden ...
Winter Variable Star Observing Activity in the
... 4.2 again, every 10 days. The magnitude scale is used to rate the brightness of a star. When the system was devised, the brightest stars were classified as “first magnitude,” and the faintest as “sixth magnitude,” which is why magnitude 3.6 is brighter than magnitude 4.2. The cycle of going from bri ...
... 4.2 again, every 10 days. The magnitude scale is used to rate the brightness of a star. When the system was devised, the brightest stars were classified as “first magnitude,” and the faintest as “sixth magnitude,” which is why magnitude 3.6 is brighter than magnitude 4.2. The cycle of going from bri ...
Theory of cooling neutron stars versus observations
... The equation of state (EOS) of superdense matter in neutron star cores is still a mystery. It is not clear if it is soft, moderate or stiff; if the matter contains nucleons/hyperons, or exotic components. In the absence of good practical theory of supranuclear matter the problem cannot be solved on ...
... The equation of state (EOS) of superdense matter in neutron star cores is still a mystery. It is not clear if it is soft, moderate or stiff; if the matter contains nucleons/hyperons, or exotic components. In the absence of good practical theory of supranuclear matter the problem cannot be solved on ...
The Stellar Initial Mass Function and Beyond
... 2001), regardless of the possible role of magnetic fields, but much more work is needed to clarify the quantitative details of this process and the initial properties of the collapsing clumps. In any case, many simulations of cloud collapse and fragmentation, both with and without turbulence, have d ...
... 2001), regardless of the possible role of magnetic fields, but much more work is needed to clarify the quantitative details of this process and the initial properties of the collapsing clumps. In any case, many simulations of cloud collapse and fragmentation, both with and without turbulence, have d ...
Colour and Luminosity Trends from the 6dFGS
... of the stellar mass function of collapsed structures Light from the near-infrared is dominated by the older and cooler stars that make up the bulk of the stellar mass. Early attempts were limited to small sky areas and/or sample sizes in the hundreds With the advent of 2MASS, more recent attempts ha ...
... of the stellar mass function of collapsed structures Light from the near-infrared is dominated by the older and cooler stars that make up the bulk of the stellar mass. Early attempts were limited to small sky areas and/or sample sizes in the hundreds With the advent of 2MASS, more recent attempts ha ...
A New Comprehensive Catalogue of Infrared Dark Clouds
... 32% of the IRDC have 24μm star association, for a total of ~ 6000 24μm point-like sources - a majority of clouds do not have any signpost of star formation (L*>100 Lo) ...
... 32% of the IRDC have 24μm star association, for a total of ~ 6000 24μm point-like sources - a majority of clouds do not have any signpost of star formation (L*>100 Lo) ...
Kein Folientitel - tls
... • Hot neptunes around several. Currently too few planets around M dwarfs to make any real conclusions ...
... • Hot neptunes around several. Currently too few planets around M dwarfs to make any real conclusions ...
Main sequence
In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell. Stars on this band are known as main-sequence stars or ""dwarf"" stars.After a star has formed, it generates thermal energy in the dense core region through the nuclear fusion of hydrogen atoms into helium. During this stage of the star's lifetime, it is located along the main sequence at a position determined primarily by its mass, but also based upon its chemical composition and other factors. All main-sequence stars are in hydrostatic equilibrium, where outward thermal pressure from the hot core is balanced by the inward pressure of gravitational collapse from the overlying layers. The strong dependence of the rate of energy generation in the core on the temperature and pressure helps to sustain this balance. Energy generated at the core makes its way to the surface and is radiated away at the photosphere. The energy is carried by either radiation or convection, with the latter occurring in regions with steeper temperature gradients, higher opacity or both.The main sequence is sometimes divided into upper and lower parts, based on the dominant process that a star uses to generate energy. Stars below about 1.5 times the mass of the Sun (or 1.5 solar masses (M☉)) primarily fuse hydrogen atoms together in a series of stages to form helium, a sequence called the proton–proton chain. Above this mass, in the upper main sequence, the nuclear fusion process mainly uses atoms of carbon, nitrogen and oxygen as intermediaries in the CNO cycle that produces helium from hydrogen atoms. Main-sequence stars with more than two solar masses undergo convection in their core regions, which acts to stir up the newly created helium and maintain the proportion of fuel needed for fusion to occur. Below this mass, stars have cores that are entirely radiative with convective zones near the surface. With decreasing stellar mass, the proportion of the star forming a convective envelope steadily increases, whereas main-sequence stars below 0.4 M☉ undergo convection throughout their mass. When core convection does not occur, a helium-rich core develops surrounded by an outer layer of hydrogen.In general, the more massive a star is, the shorter its lifespan on the main sequence. After the hydrogen fuel at the core has been consumed, the star evolves away from the main sequence on the HR diagram. The behavior of a star now depends on its mass, with stars below 0.23 M☉ becoming white dwarfs directly, whereas stars with up to ten solar masses pass through a red giant stage. More massive stars can explode as a supernova, or collapse directly into a black hole.