A spectroscopic study of detached binary systems using precise radial velocities
... orbits, whilst others result from much more active processes, such as mass exchange leading to intense radiation emissions. A complete understanding of a binary system’s orbital characteristics, as well as the measurement of the all-important stellar masses, is almost always only achieved after the ...
... orbits, whilst others result from much more active processes, such as mass exchange leading to intense radiation emissions. A complete understanding of a binary system’s orbital characteristics, as well as the measurement of the all-important stellar masses, is almost always only achieved after the ...
Article PDF - IOPscience
... Even though the PS1 3p survey holds great potential for Galactic studies due to its depth and sky coverage, it is a challenging data set for selection of RR Lyrae stars due to its sparse temporal coverage, cadence, and asynchronous multiband observations (see Figure 1). As we described in our previo ...
... Even though the PS1 3p survey holds great potential for Galactic studies due to its depth and sky coverage, it is a challenging data set for selection of RR Lyrae stars due to its sparse temporal coverage, cadence, and asynchronous multiband observations (see Figure 1). As we described in our previo ...
Spitzer Spectroscopy of Circumstellar Disks in the 5 Myr Old Upper
... In a 4–16 µm Spitzer survey of 204 members of the Upper Scorpius OB association with masses ranging from ∼0.1 to 20 M⊙ , Carpenter et al. (2006) find only 35 stars with emission in excess of photospheric values at 8 or 16 µm. The low-mass (0.1–1.2 M⊙ ) stars are associated with excess emission that ...
... In a 4–16 µm Spitzer survey of 204 members of the Upper Scorpius OB association with masses ranging from ∼0.1 to 20 M⊙ , Carpenter et al. (2006) find only 35 stars with emission in excess of photospheric values at 8 or 16 µm. The low-mass (0.1–1.2 M⊙ ) stars are associated with excess emission that ...
Spectroscopic Atlas for Amateur Astronomers
... Probably most amateur astronomers have a common experience at the beginning of their spectrographic “career”. Full of expectations they test the new device for the first time and look with great pride at the first self recorded spectrum. This first enthusiasm then quickly gives way to the perplexity ...
... Probably most amateur astronomers have a common experience at the beginning of their spectrographic “career”. Full of expectations they test the new device for the first time and look with great pride at the first self recorded spectrum. This first enthusiasm then quickly gives way to the perplexity ...
constellations - Richmond and Glen Allen Weather
... even the bright sun is dimmed toward one’s horizon at setting or rising. The apparent magnitude difference from the zenith to the horizon is approximately two magnitudes dimmer in brightness. 2. The least desirable time to observe the constellations is when the moon, brighter than a quarter phase, i ...
... even the bright sun is dimmed toward one’s horizon at setting or rising. The apparent magnitude difference from the zenith to the horizon is approximately two magnitudes dimmer in brightness. 2. The least desirable time to observe the constellations is when the moon, brighter than a quarter phase, i ...
Was the bright comet of 1742 discovered from India?
... ‘Alī took these events to be signs in the sky, given the uncertain times under a weakening Mughal Empire and the ripples of the recent invasion of Delhi in 1739 by Nādir Shāh lingering still is difficult to say. The manner in which he reports the natural occurrences, Muhammad ‘Alī comes across more ...
... ‘Alī took these events to be signs in the sky, given the uncertain times under a weakening Mughal Empire and the ripples of the recent invasion of Delhi in 1739 by Nādir Shāh lingering still is difficult to say. The manner in which he reports the natural occurrences, Muhammad ‘Alī comes across more ...
lecture course
... low brightnesses at their centres and absolute B magnitudes fainter than about -18. The faintest galaxies known are dwarf ellipticals. Elliptical galaxies are featureless, with brightness profiles that are high in the centre and lower far away from the centre. Spiral galaxies like the Milky Way and ...
... low brightnesses at their centres and absolute B magnitudes fainter than about -18. The faintest galaxies known are dwarf ellipticals. Elliptical galaxies are featureless, with brightness profiles that are high in the centre and lower far away from the centre. Spiral galaxies like the Milky Way and ...
Super-Eddington outburst in a binary system: V4641 Sgr Mikhail Revnivtsev, Marat Gilfanov
... Low mass X-ray binary • Optical companion is small M < High mass X-ray binary M . Ratio of the accretion disk size to the companion star size is • Optical companion is large M > 3 − 5M . Ratio of the accretion large disk size to the companion star size ...
... Low mass X-ray binary • Optical companion is small M < High mass X-ray binary M . Ratio of the accretion disk size to the companion star size is • Optical companion is large M > 3 − 5M . Ratio of the accretion large disk size to the companion star size ...
Confirmation of Hostless Type Ia Supernovae Using Hubble Space
... truly belonged to the intracluster stellar population we used the HST ACS to obtain deep images at their locations. We waited until >3 years after peak brightness to obtain these images to avoid contamination from the SN itself (this is discussed in Section 3.5). To either rule out or classify a fai ...
... truly belonged to the intracluster stellar population we used the HST ACS to obtain deep images at their locations. We waited until >3 years after peak brightness to obtain these images to avoid contamination from the SN itself (this is discussed in Section 3.5). To either rule out or classify a fai ...
The spectroscopic Hertzsprung-Russell diagram
... the absolute brightnesses, i.e. the distances, are required to properly order the stars in the HR diagram. Also for stars in star clusters, where the distance may still be unknown, but the distances of all stars are roughly equal, order can be achieved in what we now call color-magnitude diagrams, s ...
... the absolute brightnesses, i.e. the distances, are required to properly order the stars in the HR diagram. Also for stars in star clusters, where the distance may still be unknown, but the distances of all stars are roughly equal, order can be achieved in what we now call color-magnitude diagrams, s ...
Mission Possible: Voyage to the Stars
... temperature of 10 million Kelvin or higher. Once the protostar reaches this temperature it officially becomes a star. The extreme temperatures on the surface of the star cause the newly formed star to shine. The process of a protostar becoming a star takes approximately 10 million years. The star th ...
... temperature of 10 million Kelvin or higher. Once the protostar reaches this temperature it officially becomes a star. The extreme temperatures on the surface of the star cause the newly formed star to shine. The process of a protostar becoming a star takes approximately 10 million years. The star th ...
Catch a Comet - Innovative Teachers BG
... By the early 20th century, most comets had been named after the year of their discovery and the brightness or season of the year was specified. For example, "The Great Comet of 1680." Daily Comet of 1882. and others. In the early 20th - century when comets were discovered frequently, an agreement on ...
... By the early 20th century, most comets had been named after the year of their discovery and the brightness or season of the year was specified. For example, "The Great Comet of 1680." Daily Comet of 1882. and others. In the early 20th - century when comets were discovered frequently, an agreement on ...
The Ages of Stars
... can place events in the correct sequence and understand the relative duration of phases. But often we need to tie together observations of independent objects to arrive at an understanding of a process. Some examples include: • The formation and evolution of proto-planetary disks appear to occur in ...
... can place events in the correct sequence and understand the relative duration of phases. But often we need to tie together observations of independent objects to arrive at an understanding of a process. Some examples include: • The formation and evolution of proto-planetary disks appear to occur in ...
Simplify each expression. Assume that no denominator equals zero
... a. What product has the greatest probability of occurring? b. What is the probability of that product occurring? SOLUTION: a. The possible products are 1, 2, 3, 4, 6, 8, 9, 12, and 16. The only product that can be made by two different sets of numbers is 4 (2 • 2 and 1 • 4). So, 4 is the product ...
... a. What product has the greatest probability of occurring? b. What is the probability of that product occurring? SOLUTION: a. The possible products are 1, 2, 3, 4, 6, 8, 9, 12, and 16. The only product that can be made by two different sets of numbers is 4 (2 • 2 and 1 • 4). So, 4 is the product ...
Galaxy Sorting
... are probably so many dwarf galaxies that their combined mass probably exceeds that of all the larger galaxies taken together. But their small size and dimness make them hard to detect and we have only been able to discover them when they are relatively nearby. Hubble based his classification sche ...
... are probably so many dwarf galaxies that their combined mass probably exceeds that of all the larger galaxies taken together. But their small size and dimness make them hard to detect and we have only been able to discover them when they are relatively nearby. Hubble based his classification sche ...
Altas Farnese
... hence Eudoxus), Hipparchus, Pseudo-Eratosthenes (and presumably Eratosthenes), and Ptolemy. As a preview, I will highlight several of the more distinct differences. First, the Farnese Atlas is completely missing the later Greek constellations of Equuleus, Coma Berenices, and Antinous. Second, Hercul ...
... hence Eudoxus), Hipparchus, Pseudo-Eratosthenes (and presumably Eratosthenes), and Ptolemy. As a preview, I will highlight several of the more distinct differences. First, the Farnese Atlas is completely missing the later Greek constellations of Equuleus, Coma Berenices, and Antinous. Second, Hercul ...
The spectroscopic Hertzsprung
... that the absolute brightnesses, i.e., the distances, are required to properly order the stars in the HR diagram. Order can also be achieved for stars in star clusters where the distance may still be unknown, but the distances of all stars are roughly equal, in what we now call color-magnitude diagra ...
... that the absolute brightnesses, i.e., the distances, are required to properly order the stars in the HR diagram. Order can also be achieved for stars in star clusters where the distance may still be unknown, but the distances of all stars are roughly equal, in what we now call color-magnitude diagra ...
Galactic Stellar and Substellar Initial Mass Function Invited Review Gilles Chabrier
... kinematic shear between the thick-disk population, present in local samples, and the genuine spheroid one. This enables us to derive only an upper limit for the spheroid mass density and IMF. Within all the uncertainties, the latter is found to be similar to the one derived for globular clusters and ...
... kinematic shear between the thick-disk population, present in local samples, and the genuine spheroid one. This enables us to derive only an upper limit for the spheroid mass density and IMF. Within all the uncertainties, the latter is found to be similar to the one derived for globular clusters and ...
Evolution in circumstellar envelopes of Be stars: From disks to rings?
... disks of several Be stars. Subtle variations in the wings of optically thin and thick emission lines suggest that the conventional, static picture of the disk being in quasi-contact with the central star is justified primarily (or perhaps only) after an outburst event. Some weeks to months later, a ...
... disks of several Be stars. Subtle variations in the wings of optically thin and thick emission lines suggest that the conventional, static picture of the disk being in quasi-contact with the central star is justified primarily (or perhaps only) after an outburst event. Some weeks to months later, a ...
as PDF - Minnesota Academy of Science
... comet, made also by Professor Bond, October 10, following. The drawing below on the right (3) represents the comet as seen five days earlier, while its head W88 passing the bright star, Arcturus, which we, have chosen al! the reference star for all these figures. On the left hand is another drawing ...
... comet, made also by Professor Bond, October 10, following. The drawing below on the right (3) represents the comet as seen five days earlier, while its head W88 passing the bright star, Arcturus, which we, have chosen al! the reference star for all these figures. On the left hand is another drawing ...
Stars, Galaxies, and Beyond
... I have prepared this summary to assist in learning some of the materials relevant to the courses named. These 300–level (junior) college courses have provided a satisfying opportunity to take a more detailed but still manageable look at astronomy and astrophysics applying to space well beyond the so ...
... I have prepared this summary to assist in learning some of the materials relevant to the courses named. These 300–level (junior) college courses have provided a satisfying opportunity to take a more detailed but still manageable look at astronomy and astrophysics applying to space well beyond the so ...
Boötes
Boötes /boʊˈoʊtiːz/ is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from the Greek Βοώτης, Boōtēs, meaning herdsman or plowman (literally, ox-driver; from βοῦς bous “cow”). The ""ö"" in the name is a diaeresis, not an umlaut, meaning that each 'o' is to be pronounced separately.One of the 48 constellations described by the 2nd century astronomer Ptolemy, Boötes is now one of the 88 modern constellations. It contains the fourth brightest star in the night sky, the orange-hued Arcturus. Boötes is home to many other bright stars, including eight above the fourth magnitude and an additional 21 above the fifth magnitude, making a total of 29 stars easily visible to the naked eye.