1998 - Universitäts-Sternwarte München
... stars, can be compared with the convolved solar spectrum to derive the respective instrumental profiles. There are at least two other large scale motions that contribute to the observed line profiles: (i) stellar rotation, or, more precise, the projected rotational velocity vsini, with i as the usua ...
... stars, can be compared with the convolved solar spectrum to derive the respective instrumental profiles. There are at least two other large scale motions that contribute to the observed line profiles: (i) stellar rotation, or, more precise, the projected rotational velocity vsini, with i as the usua ...
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 ...
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 ...
A Digital Spectral Classification Atlas
... The MK Spectral classification system was founded by W.W. Morgan and P.C. Keenan in the year 1943, with the publication of the first photographic spectral classification atlas, An Atlas of Stellar Spectra (Morgan, Keenan & Kelleman, 1943). Since that time, the MK system has been extensively revised ...
... The MK Spectral classification system was founded by W.W. Morgan and P.C. Keenan in the year 1943, with the publication of the first photographic spectral classification atlas, An Atlas of Stellar Spectra (Morgan, Keenan & Kelleman, 1943). Since that time, the MK system has been extensively revised ...
Classification of Variable Stars
... Bluish Blue-white White Yellow-white Yellowish Orange Reddish Red-infrared infrared infrared infrared ...
... Bluish Blue-white White Yellow-white Yellowish Orange Reddish Red-infrared infrared infrared infrared ...
Conference Abstract Booklet here.
... The era of large-scale photometric variability surveys began a quarter of a century ago, when three microlensing projects - EROS, MACHO, and OGLE - started their operation. These surveys initiated a revolution in the field of variable stars and in the next years they inspired many new observational ...
... The era of large-scale photometric variability surveys began a quarter of a century ago, when three microlensing projects - EROS, MACHO, and OGLE - started their operation. These surveys initiated a revolution in the field of variable stars and in the next years they inspired many new observational ...
Stellar evolution - Statistical Physics Group
... into space, but direct observation of the evolution of most stars seems impossible. Typically evolutionary time scales are between loe and 10lo years. Despite this, studies of stellar evolution have progressed considerably. On the observational side, it has been realized that, although the classific ...
... into space, but direct observation of the evolution of most stars seems impossible. Typically evolutionary time scales are between loe and 10lo years. Despite this, studies of stellar evolution have progressed considerably. On the observational side, it has been realized that, although the classific ...
Abd al-Rahman al-Sufi and his book of the fixed stars: a journey of
... sky. Al-Ṣūfī’s contribution to astronomy was not only limited to writing this book but he was also instrumental in developing the science of astronomy for a very long time. He also contributed to the building of an important observatory in the city of Shiraz as well as constructing many astronomical ...
... sky. Al-Ṣūfī’s contribution to astronomy was not only limited to writing this book but he was also instrumental in developing the science of astronomy for a very long time. He also contributed to the building of an important observatory in the city of Shiraz as well as constructing many astronomical ...
Hot subdwarf stars-galactic orbits and distribution perpendicular to
... is 0.24, the average normalised z-extent nze of the orbits is 0.16, and the asymmetric drift of our sample is −36 km s−1 . This suggests that our sample of sdB stars is part of a population of thick disk stars. A statistical analysis of the orbits shows that the subdwarf stars have a spatial distrib ...
... is 0.24, the average normalised z-extent nze of the orbits is 0.16, and the asymmetric drift of our sample is −36 km s−1 . This suggests that our sample of sdB stars is part of a population of thick disk stars. A statistical analysis of the orbits shows that the subdwarf stars have a spatial distrib ...
Reassessing the formation of the inner Oort cloud
... We re-examine the formation of the inner Oort comet cloud while the Sun was in its birth cluster with the aid of numerical simulations. This work is a continuation of an earlier study (Brasser et al., 2006) with several substantial modifications. First, the system consisting of stars, planets and co ...
... We re-examine the formation of the inner Oort comet cloud while the Sun was in its birth cluster with the aid of numerical simulations. This work is a continuation of an earlier study (Brasser et al., 2006) with several substantial modifications. First, the system consisting of stars, planets and co ...
NGC 6231: a young open cluster under X-rays
... • There is no spatial trends between the cTTs and the wTTs • There is no very significant difference in their ages • Star formation in NGC 6231 was most probably not a punctual event • Formation scenario is compatible with the coalescence model for massive star formation 20-Dec-2006 ...
... • There is no spatial trends between the cTTs and the wTTs • There is no very significant difference in their ages • Star formation in NGC 6231 was most probably not a punctual event • Formation scenario is compatible with the coalescence model for massive star formation 20-Dec-2006 ...
on the pms star hbc 498 and its associated nebulous stars1
... 1978) and because they apparently constitute a tight trapezium of young stellar objects (Cohen 1980; Cohen & Kuhi 1979) associated with a small dark cloud in the direction of L1641(see Figure 1). The separation between any two stars in the trapezium is of about 0.20 pc (at a distance of 460 pc). The ...
... 1978) and because they apparently constitute a tight trapezium of young stellar objects (Cohen 1980; Cohen & Kuhi 1979) associated with a small dark cloud in the direction of L1641(see Figure 1). The separation between any two stars in the trapezium is of about 0.20 pc (at a distance of 460 pc). The ...
Infrared Properties of Star-Forming Dwarf Galaxies. I. Dwarf Irregular
... more than 50% of the light from star formation bursts within the last 3 Gyr. In most cases, the resolved population down to MKs ¼ 7:5 represents less than 5% of the total NIR flux in Ks, with fractions in J being 1.5–2 times larger. Thus, the NIR light of dIs can be considered to be predominantly c ...
... more than 50% of the light from star formation bursts within the last 3 Gyr. In most cases, the resolved population down to MKs ¼ 7:5 represents less than 5% of the total NIR flux in Ks, with fractions in J being 1.5–2 times larger. Thus, the NIR light of dIs can be considered to be predominantly c ...
Rocky planetesimals as the origin of metals in DZ stars
... where hydrogen is detected or inferred (Dufour et al. 2007) versus height above the Galactic mid-plane and tangential speed. No obvious pattern is seen, although there may be a higher density of DZA stars near the Galactic disc and perhaps also towards more modest speeds, but the former may be an ob ...
... where hydrogen is detected or inferred (Dufour et al. 2007) versus height above the Galactic mid-plane and tangential speed. No obvious pattern is seen, although there may be a higher density of DZA stars near the Galactic disc and perhaps also towards more modest speeds, but the former may be an ob ...
A Star - Cloudy Nights
... All the stars you can see without a telescope, including our Sun, are located in the same spiral arm of the Milky Way galaxy. Even though these stars are our neighbors, we can't visit them. They are too far away. Using current technology, it would take thousands of years to travel to our closest ste ...
... All the stars you can see without a telescope, including our Sun, are located in the same spiral arm of the Milky Way galaxy. Even though these stars are our neighbors, we can't visit them. They are too far away. Using current technology, it would take thousands of years to travel to our closest ste ...
DUSTY CIRCUMSTELLAR DISKS B. Zuckerman
... and distance determinations with the Hipparcos satellite, indicate that the TW Hya Association (hereafter TWA) is about 10 million years old and only ∼60 pc from Earth (Webb et al. 1999). The primary reason this close T Tauri Association went unrecognized for so long is that the massive molecular cl ...
... and distance determinations with the Hipparcos satellite, indicate that the TW Hya Association (hereafter TWA) is about 10 million years old and only ∼60 pc from Earth (Webb et al. 1999). The primary reason this close T Tauri Association went unrecognized for so long is that the massive molecular cl ...
Astronomy 250 - University of Victoria
... need only measure the displacement ∆λ of a spectral line from its expected wavelength λ, provided the latter is known. The radial velocity, vr , is then given by ...
... need only measure the displacement ∆λ of a spectral line from its expected wavelength λ, provided the latter is known. The radial velocity, vr , is then given by ...
Stellarium User Guide - Skolekonsulenterne.dk
... planetarium. It will calculate the positions of the Sun and Moon, planets and stars, and draw how the sky would look to an observer depending on their location and the time. It can also draw the constellations and simulate astronomical phenomena such as meteor showers, and solar or lunar eclipses. S ...
... planetarium. It will calculate the positions of the Sun and Moon, planets and stars, and draw how the sky would look to an observer depending on their location and the time. It can also draw the constellations and simulate astronomical phenomena such as meteor showers, and solar or lunar eclipses. S ...
Abstracts - Physics of Evolved Stars 2015
... and planetary-nebula stages. AGB stars lose most of their stellar envelope in the form of a gaseous and dusty stellar wind. This wind eventually grows to such high mass-loss rates that the central star becomes entirely enshrouded by a dense, dusty superwind. Before reaching such high massloss rates, ...
... and planetary-nebula stages. AGB stars lose most of their stellar envelope in the form of a gaseous and dusty stellar wind. This wind eventually grows to such high mass-loss rates that the central star becomes entirely enshrouded by a dense, dusty superwind. Before reaching such high massloss rates, ...
Auriga (constellation)
Auriga is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy and remains one of the 88 modern constellations. Located north of the celestial equator, its name is the Latin word for ""charioteer"", associating it with various mythological charioteers, including Erichthonius and Myrtilus. Auriga is most prominent during winter evenings in the Northern Hemisphere, along with the five other constellations that have stars in the Winter Hexagon asterism. Because of its northern declination, Auriga is only visible in its entirety as far as 34° south; for observers farther south it lies partially or fully below the horizon. A large constellation, with an area of 657 square degrees, it is half the size of the largest constellation, Hydra.Its brightest star, Capella, is an unusual multiple star system among the brightest stars in the night sky. Beta Aurigae is an interesting variable star in the constellation; Epsilon Aurigae, a nearby eclipsing binary with an unusually long period, has been studied intensively. Because of its position near the winter Milky Way, Auriga has many bright open clusters in its borders, including M36, M37, and M38, popular targets for amateur astronomers. In addition, it has one prominent nebula, the Flaming Star Nebula, associated with the variable star AE Aurigae.In Chinese mythology, Auriga's stars were incorporated into several constellations, including the celestial emperors' chariots, made up of the modern constellation's brightest stars. Auriga is home to the radiant for the Aurigids, Zeta Aurigids, Delta Aurigids, and the hypothesized Iota Aurigids.