TOPS: Toward Other Planetary
... throughout the universe, the nature of those systems, and the likelihood that other planets have given birth to life, even advanced and intelligent forms of life. We live in a remarkable time, when human beings, after thousands of years of wondering, have attained the possibility of finding the firs ...
... throughout the universe, the nature of those systems, and the likelihood that other planets have given birth to life, even advanced and intelligent forms of life. We live in a remarkable time, when human beings, after thousands of years of wondering, have attained the possibility of finding the firs ...
Introduction to Galaxies - West Jefferson Local Schools
... Recall, luminosity of stars scales with mass of stars… therefore, luminosity of galaxy scales with number of stars (and thus, mass of stars). Thus, luminosity of galaxy gives mass of galaxy. Going backwards… measure the velocity to “weigh” the galaxy to obtain luminosity. ...
... Recall, luminosity of stars scales with mass of stars… therefore, luminosity of galaxy scales with number of stars (and thus, mass of stars). Thus, luminosity of galaxy gives mass of galaxy. Going backwards… measure the velocity to “weigh” the galaxy to obtain luminosity. ...
Star formation in a galactic outflow
... population with kinematical fingerprints of formation inside the outflow. The stellar continuum is detected in the X-shooter spectra out to about 5 kpc from the nucleus, and its shape and stellar features do indeed indicate the presence of a young stellar population younger than a few tens of millio ...
... population with kinematical fingerprints of formation inside the outflow. The stellar continuum is detected in the X-shooter spectra out to about 5 kpc from the nucleus, and its shape and stellar features do indeed indicate the presence of a young stellar population younger than a few tens of millio ...
STELLAR AGE VERSUS MASS OF EARLY
... performed visually by allowing age steps of 0.05 dex. The age range was then kept fixed for the other colors (middle and bottom panel). We see from the top panel of Fig. 2 that the SSP of HPL07 exceeds the observed color range at intermediate ages. This is no surprise, though: since the reddest colo ...
... performed visually by allowing age steps of 0.05 dex. The age range was then kept fixed for the other colors (middle and bottom panel). We see from the top panel of Fig. 2 that the SSP of HPL07 exceeds the observed color range at intermediate ages. This is no surprise, though: since the reddest colo ...
Is $^ 6$ Li in metal-poor halo stars produced in situ by solar
... It has been known for many years that the chromospheric and coronal activities of dwarf stars are closely related to their rotation (Kraft 1967). This relationship results from the generation and amplification of surface magnetic fields by a complex dynamo mechanism, whose efficiency depends on the in ...
... It has been known for many years that the chromospheric and coronal activities of dwarf stars are closely related to their rotation (Kraft 1967). This relationship results from the generation and amplification of surface magnetic fields by a complex dynamo mechanism, whose efficiency depends on the in ...
Reassessing the formation of the inner Oort cloud
... For most embedded clusters, the observed surface density is a constant (Allen et al., 2007) i.e. N/R2 is constant, where R is the radius of the cluster. This relation is in agreement with the observed density structure of giant molecular clouds (Blitz et al., 2007) and theoretical modelling of cloud ...
... For most embedded clusters, the observed surface density is a constant (Allen et al., 2007) i.e. N/R2 is constant, where R is the radius of the cluster. This relation is in agreement with the observed density structure of giant molecular clouds (Blitz et al., 2007) and theoretical modelling of cloud ...
Radial Velocity - Yale Exoplanet
... and provided a precise wavelength solution spanning about 50 Å. The spectrum was recorded with a photon-counting Reticon photodiode array. Working from 1980 to 1992, they monitored 17 main sequence stars and 4 subgiant stars and achieved the unprecedented precision of 15 m s−1 . Unfortunately, beca ...
... and provided a precise wavelength solution spanning about 50 Å. The spectrum was recorded with a photon-counting Reticon photodiode array. Working from 1980 to 1992, they monitored 17 main sequence stars and 4 subgiant stars and achieved the unprecedented precision of 15 m s−1 . Unfortunately, beca ...
Program and Abstract Book - European Southern Observatory
... temperatures. Herschel observations of the cold and low density molecular gas extending tens of parsecs, that constitutes the bulk of the molecular clouds of the Milky Way, have shown a network of dense structures in the shape of filaments. These filaments supposedly condense into higher density clu ...
... temperatures. Herschel observations of the cold and low density molecular gas extending tens of parsecs, that constitutes the bulk of the molecular clouds of the Milky Way, have shown a network of dense structures in the shape of filaments. These filaments supposedly condense into higher density clu ...
MEarth
... brought about by the small surface areas and temperatures of M dwarfs, which lead to significantly more favorable planet-star contrast ratios. This ratio for a habitable 2 R⊕ planet orbiting an M5 is 0.05% (in the Rayleigh-Jeans limit), leading to secondary eclipse depths well reachable with Spitz ...
... brought about by the small surface areas and temperatures of M dwarfs, which lead to significantly more favorable planet-star contrast ratios. This ratio for a habitable 2 R⊕ planet orbiting an M5 is 0.05% (in the Rayleigh-Jeans limit), leading to secondary eclipse depths well reachable with Spitz ...
FIRST STELLAR ABUNDANCES IN THE DWARF IRREGULAR
... stars, thermal pulsing in low and intermediate mass AGB stars. Thus, more elements than just those observed in nebulae need to be measured, since each have different formation sites which sample different constituents. The α elements like oxygen are created primarily in short-lived massive stars, wh ...
... stars, thermal pulsing in low and intermediate mass AGB stars. Thus, more elements than just those observed in nebulae need to be measured, since each have different formation sites which sample different constituents. The α elements like oxygen are created primarily in short-lived massive stars, wh ...
Spectroscopic Atlas for Amateur Astronomers
... edition: “Atlas for Objective Prism Spectra” by Waltraut C. Seitter, 1975 [5]). This atlas, covering the spectral types from O5 to M2, is out of print today, but recently available as download [5]! Still based on photographic spectral strips it’s the only reviewed work, documenting most of the lines ...
... edition: “Atlas for Objective Prism Spectra” by Waltraut C. Seitter, 1975 [5]). This atlas, covering the spectral types from O5 to M2, is out of print today, but recently available as download [5]! Still based on photographic spectral strips it’s the only reviewed work, documenting most of the lines ...
The Perseid Meteor Shower
... Swift-Tuttle. It is named after two American scientists who discovered the comet in 1862. The scientists were not working together. They were each looking through their own telescopes and saw the comet. Lewis Swift saw it first and then, three days later, Horace Tuttle saw it. As the comet got close ...
... Swift-Tuttle. It is named after two American scientists who discovered the comet in 1862. The scientists were not working together. They were each looking through their own telescopes and saw the comet. Lewis Swift saw it first and then, three days later, Horace Tuttle saw it. As the comet got close ...
English version - Richard de Grijs
... Chandra’s images are giving the astronomers a closer-than-ever look at the distinctive geometry of the charged particle winds radiating in X-rays and other wavelengths from the objects, according to Posselt. Pulsar wind nebulae (PWN) are produced when the energetic particles streaming from pulsar ...
... Chandra’s images are giving the astronomers a closer-than-ever look at the distinctive geometry of the charged particle winds radiating in X-rays and other wavelengths from the objects, according to Posselt. Pulsar wind nebulae (PWN) are produced when the energetic particles streaming from pulsar ...
ALFALFA H-alpha: The Star-Formation-Rate Density
... Over one hundred billion stars lie in the Milky Way galaxy, a moderate-sized galaxy in a universe of roughly one hundred billion galaxies. These galaxies thus amount to 1022 (ten sextillion) stars in our Universe. The science of astronomy allows us to contemplate such grand numbers and to investigat ...
... Over one hundred billion stars lie in the Milky Way galaxy, a moderate-sized galaxy in a universe of roughly one hundred billion galaxies. These galaxies thus amount to 1022 (ten sextillion) stars in our Universe. The science of astronomy allows us to contemplate such grand numbers and to investigat ...
The Chemical Composition of Carbon-Rich, Very Metal
... of Beers, Preston & Shectman 1992; Beers 1999), which have identified objects as metal-poor as [Fe/H]= −4 5 . One unexpected result of the HK survey is that many (∼ 10-15%) of the most metal-poor stars exhibit anomalously strong CH bands, most easily understood in terms of an excess of carbon in the ...
... of Beers, Preston & Shectman 1992; Beers 1999), which have identified objects as metal-poor as [Fe/H]= −4 5 . One unexpected result of the HK survey is that many (∼ 10-15%) of the most metal-poor stars exhibit anomalously strong CH bands, most easily understood in terms of an excess of carbon in the ...
Astronomy Astrophysics
... present the results of the analysis of the NLTE cores of 22 DA white dwarfs covering the temperature range from 6800 K to 20 000 K. This is an extension of our previous investigation (Heber et al. 1997, henceforth Paper I) to lower temperatures. The analysis is based on the spectra obtained by Reid ...
... present the results of the analysis of the NLTE cores of 22 DA white dwarfs covering the temperature range from 6800 K to 20 000 K. This is an extension of our previous investigation (Heber et al. 1997, henceforth Paper I) to lower temperatures. The analysis is based on the spectra obtained by Reid ...
Marking Scheme of Observational Sessions
... observer can mark those Deep Sky Objects ( IF THEY CAN BE SEEN IN NAKED EYE ) by using standard symbols . Eg : - Observer can mark Orion nebula (by a Symbol) in its position ( at the constellation of “Orion”) in his/her constellation mapping drawing. But drawing Orion nebula IS NOT ACCEPTABLE ! Maxi ...
... observer can mark those Deep Sky Objects ( IF THEY CAN BE SEEN IN NAKED EYE ) by using standard symbols . Eg : - Observer can mark Orion nebula (by a Symbol) in its position ( at the constellation of “Orion”) in his/her constellation mapping drawing. But drawing Orion nebula IS NOT ACCEPTABLE ! Maxi ...
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 ...
Classification of Variable Stars
... QZ. This system (the letter J is omitted) can accommodate 334 names. There are so many variables in some constellations in the Milky Way, however, that additional nomenclature is necessary. After QZ, variables are named V335, V336, and so on. The letters representing stars are then combined with the ...
... QZ. This system (the letter J is omitted) can accommodate 334 names. There are so many variables in some constellations in the Milky Way, however, that additional nomenclature is necessary. After QZ, variables are named V335, V336, and so on. The letters representing stars are then combined with the ...
High-precision abundances of elements in solar twin stars: Trends
... ance of Fe lines. Non-LTE effects are considered and taken into account for some of the elements. In addition, precise (σ ∼ stellar ages are obtained by interpolating between Yonsei-Yale isochrones in the log g-T eff diagram. Results. It is confirmed that the ratio between refractory and volatile el ...
... ance of Fe lines. Non-LTE effects are considered and taken into account for some of the elements. In addition, precise (σ ∼ stellar ages are obtained by interpolating between Yonsei-Yale isochrones in the log g-T eff diagram. Results. It is confirmed that the ratio between refractory and volatile el ...
Cygnus (constellation)
Cygnus /ˈsɪɡnəs/ is a northern constellation lying on the plane of the Milky Way, deriving its name from the Latinized Greek word for swan. The swan is one of the most recognizable constellations of the northern summer and autumn, it features a prominent asterism known as the Northern Cross (in contrast to the Southern Cross). Cygnus was among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.Cygnus contains Deneb, one of the brightest stars in the night sky and one corner of the Summer Triangle, as well as some notable X-ray sources and the giant stellar association of Cygnus OB2. One of the stars of this association, NML Cygni, is one of the largest stars currently known. The constellation is also home to Cygnus X-1, a distant X-ray binary containing a supergiant and unseen massive companion that was the first object widely held to be a black hole. Many star systems in Cygnus have known planets as a result of the Kepler Mission observing one patch of the sky, the patch is the area around Cygnus. In addition, most of the eastern part of Cygnus is dominated by the Hercules–Corona Borealis Great Wall, a giant galaxy filament that is the largest known structure in the observable universe; covering most of the northern sky.