A spectroscopic investigation of the O
... which no evidence of binarity is found can never be definitely considered as single. Even if no RV shift is detected, the system could be seen under a particular orientation, have a very long period or perhaps a high eccentricity, thereby making the RV variations not significant over a long timescal ...
... which no evidence of binarity is found can never be definitely considered as single. Even if no RV shift is detected, the system could be seen under a particular orientation, have a very long period or perhaps a high eccentricity, thereby making the RV variations not significant over a long timescal ...
Absolute magnitudes and kinematics of barium
... (Jorissen & Boffin 1992) and that the orbital period is related to the orbital separation. It may be possible that mild barium stars have wider separations between components, making more difficult the detection of their binary nature. If we consider the stars with known orbits or with variable radi ...
... (Jorissen & Boffin 1992) and that the orbital period is related to the orbital separation. It may be possible that mild barium stars have wider separations between components, making more difficult the detection of their binary nature. If we consider the stars with known orbits or with variable radi ...
Evidence for the Tidal Destruction of Hot Jupiters by Subgiant Stars
... dispersion of a thin-disk population increases with age (e.g., Binney et al. 2000). This is understood as follows. Thin disk stars form from dense, turbulent gas in the Galactic plane. Because that process is highly dissipative, stellar populations are formed with a very cold velocity distribution. ...
... dispersion of a thin-disk population increases with age (e.g., Binney et al. 2000). This is understood as follows. Thin disk stars form from dense, turbulent gas in the Galactic plane. Because that process is highly dissipative, stellar populations are formed with a very cold velocity distribution. ...
Red Objects in the DFBS
... • These instrumental magnitudes are linked to the USNO scale using the objects in the central square degree of the plate: a linear fit is made in the magnitude range 12 to 16 both for the B and R magnitudes. • Overlapped objects and most discrepant objects are excluded from the fit and a second iter ...
... • These instrumental magnitudes are linked to the USNO scale using the objects in the central square degree of the plate: a linear fit is made in the magnitude range 12 to 16 both for the B and R magnitudes. • Overlapped objects and most discrepant objects are excluded from the fit and a second iter ...
The ages of pre-main-sequence stars
... The position of pre-main-sequence or protostars in the Hertzsprung±Russell diagram is often used to determine their mass and age by comparison with pre-main-sequence evolution tracks. On the assumption that the stellar models are accurate, we demonstrate that, if the metallicity is known, the mass o ...
... The position of pre-main-sequence or protostars in the Hertzsprung±Russell diagram is often used to determine their mass and age by comparison with pre-main-sequence evolution tracks. On the assumption that the stellar models are accurate, we demonstrate that, if the metallicity is known, the mass o ...
DUSTY CIRCUMSTELLAR DISKS B. Zuckerman
... The narrow containment of the ring particles and the abrupt inner and outer truncation of the ring around this relatively young star suggests dynamical constraints imposed by one or more related, but as yet unseen, bodies. The question of how such bodies, presumably planets or planetary embryos, cou ...
... The narrow containment of the ring particles and the abrupt inner and outer truncation of the ring around this relatively young star suggests dynamical constraints imposed by one or more related, but as yet unseen, bodies. The question of how such bodies, presumably planets or planetary embryos, cou ...
Dr. Amanda Karakas and Prof. John Lattanzio
... 3. Binary evolution channels: mass loss, envelope ejection, Type Ia supernova and nova explosions ...
... 3. Binary evolution channels: mass loss, envelope ejection, Type Ia supernova and nova explosions ...
Chapter 18 - Astro1010
... shed before the star can become a White Dwarf. The star shrinks by gravity but remains bright by the surface getting hotter. Stars over 1.4 Solar masses also must rid themselves of the extra mass. ...
... shed before the star can become a White Dwarf. The star shrinks by gravity but remains bright by the surface getting hotter. Stars over 1.4 Solar masses also must rid themselves of the extra mass. ...
The Nature of the Stars
... away that their parallax angles are too small to measure even with an orbiting telescope. Later in this chapter, we will discuss a technique that can be used to find the distances to these more remote stars. In Chapters 24 and 26 we will learn about other techniques that astronomers use to determine ...
... away that their parallax angles are too small to measure even with an orbiting telescope. Later in this chapter, we will discuss a technique that can be used to find the distances to these more remote stars. In Chapters 24 and 26 we will learn about other techniques that astronomers use to determine ...
Stellar Spectroscopy
... surface of the star, but most of what is known about stars is determined from the many spectral lines seen in their spectrum. A close inspection of a star’s spectrum will reveal many absorption lines, and for some stars, emission lines as well. These spectral lines can be used to determine an incred ...
... surface of the star, but most of what is known about stars is determined from the many spectral lines seen in their spectrum. A close inspection of a star’s spectrum will reveal many absorption lines, and for some stars, emission lines as well. These spectral lines can be used to determine an incred ...
Introduction
... Irregular/peculiar galaxies follow neither the disk nor elliptical plans; they lack apparent rotational symmetry. ...
... Irregular/peculiar galaxies follow neither the disk nor elliptical plans; they lack apparent rotational symmetry. ...
Fast Auto-Focus Method and Software for CCD
... HFD Auto-Focus Strategy To begin, the user must characterize the telescope-CCD-focuser system by automatically measuring the V Curve and extracting the three parameters. In principle, the Best Focus Position can be determined with a measured target star HFD, the position of the focuser and knowledge ...
... HFD Auto-Focus Strategy To begin, the user must characterize the telescope-CCD-focuser system by automatically measuring the V Curve and extracting the three parameters. In principle, the Best Focus Position can be determined with a measured target star HFD, the position of the focuser and knowledge ...
Fast Auto-Focus Method and Software for CCD-based
... HFD Auto-Focus Strategy To begin, the user must characterize the telescope-CCD-focuser system by automatically measuring the V Curve and extracting the three parameters. In principle, the Best Focus Position can be determined with a measured target star HFD, the position of the focuser and knowledg ...
... HFD Auto-Focus Strategy To begin, the user must characterize the telescope-CCD-focuser system by automatically measuring the V Curve and extracting the three parameters. In principle, the Best Focus Position can be determined with a measured target star HFD, the position of the focuser and knowledg ...
Word - Stefan`s Florilegium
... pulley. The other end of the string was connected to a weight while a shaft connected the pulley to a pointer. As the water level in the collection container rose, so too would the float. This would cause the weight at the other end of the string to fall and the pulley, with the attached pointer, to ...
... pulley. The other end of the string was connected to a weight while a shaft connected the pulley to a pointer. As the water level in the collection container rose, so too would the float. This would cause the weight at the other end of the string to fall and the pulley, with the attached pointer, to ...
A spectroscopic investigation of the O-type star - ORBi
... evidence of binarity is found can never be definitely considered as single. Even if no RV shift is detected, the system could be seen under a particular orientation, have a very long period or perhaps a high eccentricity, thereby making the RV variations not significant over a long timescale. We per ...
... evidence of binarity is found can never be definitely considered as single. Even if no RV shift is detected, the system could be seen under a particular orientation, have a very long period or perhaps a high eccentricity, thereby making the RV variations not significant over a long timescale. We per ...
Chapter 12: Surveying the Stars 12.1 Properties of Stars How do we
... Thought Question How would the apparent brightness of Alpha Centauri change if it were three times farther away? A. It would be only 1/3 as bright. B. It would be only 1/6 as bright. C. It would be only 1/9 as bright. D. It would be three times as bright. So how far away are these stars? © 2015 ...
... Thought Question How would the apparent brightness of Alpha Centauri change if it were three times farther away? A. It would be only 1/3 as bright. B. It would be only 1/6 as bright. C. It would be only 1/9 as bright. D. It would be three times as bright. So how far away are these stars? © 2015 ...
east and west encounter at sea
... Let us make now a very rapid review of the techniques of each other’s areas of sailing, which later will be justified more deeply, specially the ones used in the Indian and Pacific Oceans. The Portuguese used in coastal navigation the lead line and in the East this very rudimentary instrument was al ...
... Let us make now a very rapid review of the techniques of each other’s areas of sailing, which later will be justified more deeply, specially the ones used in the Indian and Pacific Oceans. The Portuguese used in coastal navigation the lead line and in the East this very rudimentary instrument was al ...
Supernovae - University of Texas Astronomy Home Page
... star that must leave behind some sort of compact remnant, either a neutron star or black hole, and the other that blows the star, believed to be a white dwarf, to smithereens, leaving no compact object. A more subtle, but significant, clue is that when a compact object is observed, there is evidence ...
... star that must leave behind some sort of compact remnant, either a neutron star or black hole, and the other that blows the star, believed to be a white dwarf, to smithereens, leaving no compact object. A more subtle, but significant, clue is that when a compact object is observed, there is evidence ...
Complete Lecture Notes (pdf file)
... • colours (colour indices): relative magnitudes in different wavelength bands, most commonly used: B − V, U − B • define bolometric correction: B.C. = Mbol − MV (usually tabulated as a function of B − V colour) • visual extinction AV : absorption of visual star light due to extinction by interstella ...
... • colours (colour indices): relative magnitudes in different wavelength bands, most commonly used: B − V, U − B • define bolometric correction: B.C. = Mbol − MV (usually tabulated as a function of B − V colour) • visual extinction AV : absorption of visual star light due to extinction by interstella ...
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.