Nikon Action Extremes 8x40, 10x50 and 12x50
... For detailed viewing, only the central 50%, possibly to 60% in the Orion, is effective. For wide angled finding, you could use the field out to 70%. The net effective field out to 70% provides a 4.25° usable field of view in both models of 10x50. Beyond that, everything is distorted. None of these t ...
... For detailed viewing, only the central 50%, possibly to 60% in the Orion, is effective. For wide angled finding, you could use the field out to 70%. The net effective field out to 70% provides a 4.25° usable field of view in both models of 10x50. Beyond that, everything is distorted. None of these t ...
Relativistic stellar aberration for the Space Interferometry Mission
... respect to the deflector. For the astrometric accuracy of a few µas and, in the case when the Sun is the deflector, positions of all observed sources experiencing such an apparent displacement, except the ones that are on exactly opposite side from the instrument with respect to the Sun, e.g. χ = ±π ...
... respect to the deflector. For the astrometric accuracy of a few µas and, in the case when the Sun is the deflector, positions of all observed sources experiencing such an apparent displacement, except the ones that are on exactly opposite side from the instrument with respect to the Sun, e.g. χ = ±π ...
Navigating the Night Sky Checklist
... The ecliptic marks the path of the sun. It’s the projection of Earth’s orbit onto the sky. And it’s an essential part of any stargazer’s vocabulary. ...
... The ecliptic marks the path of the sun. It’s the projection of Earth’s orbit onto the sky. And it’s an essential part of any stargazer’s vocabulary. ...
Oxygen and Neon Abundances of B-Type Stars in Comparison with
... Simón-Dı́az 2010). In our opinion, however, these studies are not necessarily adequate from the viewpoint of precisely investigating star Sun differential oxygen abundances, because the abundances were established mostly from O II lines1 (particularly seen in the spectra of early-B stars), and we ...
... Simón-Dı́az 2010). In our opinion, however, these studies are not necessarily adequate from the viewpoint of precisely investigating star Sun differential oxygen abundances, because the abundances were established mostly from O II lines1 (particularly seen in the spectra of early-B stars), and we ...
Laboratory A
... 10. On the scale drawing of the NPOI site, 1 in is 140 ft. What is this in centimeters to meters? 2.54 cm to 42.672 m, or 1 cm to 16.8 m 11. On the scale drawing of the NPOI site, 1 in is 140 ft. What are the dimensions of the Beam Combing Building on the drawing in inches? length = 1,125/3,556 in, ...
... 10. On the scale drawing of the NPOI site, 1 in is 140 ft. What is this in centimeters to meters? 2.54 cm to 42.672 m, or 1 cm to 16.8 m 11. On the scale drawing of the NPOI site, 1 in is 140 ft. What are the dimensions of the Beam Combing Building on the drawing in inches? length = 1,125/3,556 in, ...
Gas Mass Fractions and the Evolution of Spiral Galaxies
... final fg . Rather than convolve together all these uncertainties, we simply use equation (5), realizing that this is probably the greatest uncertainty in the process. The uncertainty in the correction for molecular gas will have little impact on our final results. The correction is only important in ...
... final fg . Rather than convolve together all these uncertainties, we simply use equation (5), realizing that this is probably the greatest uncertainty in the process. The uncertainty in the correction for molecular gas will have little impact on our final results. The correction is only important in ...
11 - Visual Magnitudes Project
... 10 is raised the exponent of magnitude difference divided by -2.5, not 10 times magnitude difference divided by -2.5. Be careful with this calculation. The -2.5 in the exponent tweaks the equations to match Hipparchus' original visual magnitude scale with smaller magnitude being brighter and larger ...
... 10 is raised the exponent of magnitude difference divided by -2.5, not 10 times magnitude difference divided by -2.5. Be careful with this calculation. The -2.5 in the exponent tweaks the equations to match Hipparchus' original visual magnitude scale with smaller magnitude being brighter and larger ...
Statistical analysis of stellar evolution
... aim is to fit physically meaningful stellar parameters and compare stellar evolution models by developing principled statistical methods that directly incorporate the evolution models via state-of-the-art complex computer models. We focus on developing methods for the analysis of CMDs of the stars i ...
... aim is to fit physically meaningful stellar parameters and compare stellar evolution models by developing principled statistical methods that directly incorporate the evolution models via state-of-the-art complex computer models. We focus on developing methods for the analysis of CMDs of the stars i ...
Astron 104 Laboratory #9 Cepheid Variable Stars
... actually radiating into space (i.e, how bright it actually is). • The star’s distance from us. In principle, if we know the first two of these quantities, we can calculate the distance. The apparent magnitude is usually easy to measure because all we need to do is use a telescope that has a calibrat ...
... actually radiating into space (i.e, how bright it actually is). • The star’s distance from us. In principle, if we know the first two of these quantities, we can calculate the distance. The apparent magnitude is usually easy to measure because all we need to do is use a telescope that has a calibrat ...
Binarity in carbon-enhanced metal-poor stars
... have in the meantime been added (Hansen, Andersen & Nordtröm 2012, also see Andersen et al. in preparation). They find that two out of their sample of eight CEMP-no stars are in binary systems. Due to these small numbers, it is not at all clear if CEMP-no stars have binary companions, and the prese ...
... have in the meantime been added (Hansen, Andersen & Nordtröm 2012, also see Andersen et al. in preparation). They find that two out of their sample of eight CEMP-no stars are in binary systems. Due to these small numbers, it is not at all clear if CEMP-no stars have binary companions, and the prese ...
CHaracterising ExOPlanets Satellite arXiv:1310.7800v1 [astro
... Space Agency. It will carry out follow-up measurements on transiting planets. This requires exquisite data that can be acquired only by a space-borne observatory and by well understood and mitigated sources of noise. Earth stray light is one of them which becomes the most prominent noise for faint s ...
... Space Agency. It will carry out follow-up measurements on transiting planets. This requires exquisite data that can be acquired only by a space-borne observatory and by well understood and mitigated sources of noise. Earth stray light is one of them which becomes the most prominent noise for faint s ...
Elliptical Galaxies
... This ambiguity can be avoided altogether for lowluminosity ellipticals or spiral bulges as we believe them to have isotropic dispersions so determining the mass distributions in these systems is more straightforward. Similarly if galaxies possess disks of excited or ionized gas we can trace the mass ...
... This ambiguity can be avoided altogether for lowluminosity ellipticals or spiral bulges as we believe them to have isotropic dispersions so determining the mass distributions in these systems is more straightforward. Similarly if galaxies possess disks of excited or ionized gas we can trace the mass ...
A Digital Spectral Classification Atlas
... MK system is defined by a set of standard stars, and classification on the system is carried out by the comparison of the program star with the standard stars, taking into account all of the features in the spectrum. The use of standards is vital because it maintains the autonomy of the system as we ...
... MK system is defined by a set of standard stars, and classification on the system is carried out by the comparison of the program star with the standard stars, taking into account all of the features in the spectrum. The use of standards is vital because it maintains the autonomy of the system as we ...
RAL Space brochure - Science and Technology Facilities Council
... Solar Orbiter was selected in October 2011 as ESA’s M class mission scheduled for launch in 2017. The mission is highly challenging, using repeated flybys of Venus to enable the spacecraft to climb out of the ecliptic, allowing it to make the first high latitude observations of the solar atmosphere. ...
... Solar Orbiter was selected in October 2011 as ESA’s M class mission scheduled for launch in 2017. The mission is highly challenging, using repeated flybys of Venus to enable the spacecraft to climb out of the ecliptic, allowing it to make the first high latitude observations of the solar atmosphere. ...
Candidate star clusters toward the inner Milky Way discovered on
... We run six different kernel overdensity searches on a sample of ∼266 000 stars from one pawprint from the stacked deep KS -band image. Similar to Piatti et al. (2016) we adopted a cutoff density of 0.05 arcsec−2 , which is a factor of 1.25 higher than the typical background surface density of 0.04 a ...
... We run six different kernel overdensity searches on a sample of ∼266 000 stars from one pawprint from the stacked deep KS -band image. Similar to Piatti et al. (2016) we adopted a cutoff density of 0.05 arcsec−2 , which is a factor of 1.25 higher than the typical background surface density of 0.04 a ...
Article PDF - IOPscience
... indicators, the white dwarf population sampled must be as close as possible to being statistically complete. The white dwarf population is composed mainly of lowluminosity stars that are rather difficult to study as we move further away from the Sun. Candidates are mainly discovered from either prop ...
... indicators, the white dwarf population sampled must be as close as possible to being statistically complete. The white dwarf population is composed mainly of lowluminosity stars that are rather difficult to study as we move further away from the Sun. Candidates are mainly discovered from either prop ...
The Origin and Evolution of Dust in Galaxies
... Star formation rate (SFR) > Gas injection rate from SNe and AGB LMC star formation depends on the large reservoir of existing ISM gas The LMC is getting gas poorer. The SFR is likely to be declining with time. Chemical evolution of the LMC ISM is very slow process (~1 Gyrs) – ISM gas : 8x108 Msun (H ...
... Star formation rate (SFR) > Gas injection rate from SNe and AGB LMC star formation depends on the large reservoir of existing ISM gas The LMC is getting gas poorer. The SFR is likely to be declining with time. Chemical evolution of the LMC ISM is very slow process (~1 Gyrs) – ISM gas : 8x108 Msun (H ...
PDF 523 KB
... from this fact. In some languages, like for example Spanish, still names of days of the week are closely matching names of planets. The country of origin of that is probably ancient Babylon, where astronomy was highly developed. Five planets inherited from Babylon and Egypt by Greece, then by Romans ...
... from this fact. In some languages, like for example Spanish, still names of days of the week are closely matching names of planets. The country of origin of that is probably ancient Babylon, where astronomy was highly developed. Five planets inherited from Babylon and Egypt by Greece, then by Romans ...
Andromeda: Daughter of Cassiopeia Ἀνδρομέδη Kaitlyn Heaton
... The Andromeda Galaxy. (Shown in figure 2) is the most distant object visible to the naked eye. You can find this famous galaxy on the right side of Andromeda, about half-way up the constellation. [2] It is a spiral galaxy approximately 2.5 million light years distant. In the past, it was also referr ...
... The Andromeda Galaxy. (Shown in figure 2) is the most distant object visible to the naked eye. You can find this famous galaxy on the right side of Andromeda, about half-way up the constellation. [2] It is a spiral galaxy approximately 2.5 million light years distant. In the past, it was also referr ...
Observational astronomy
Observational astronomy is a division of the astronomical science that is concerned with recording data, in contrast with theoretical astrophysics, which is mainly concerned with finding out the measurable implications of physical models. It is the practice of observing celestial objects by using telescopes and other astronomical apparatus.As a science, the study of astronomy is somewhat hindered in that direct experiments with the properties of the distant universe are not possible. However, this is partly compensated by the fact that astronomers have a vast number of visible examples of stellar phenomena that can be examined. This allows for observational data to be plotted on graphs, and general trends recorded. Nearby examples of specific phenomena, such as variable stars, can then be used to infer the behavior of more distant representatives. Those distant yardsticks can then be employed to measure other phenomena in that neighborhood, including the distance to a galaxy.Galileo Galilei turned a telescope to the heavens and recorded what he saw. Since that time, observational astronomy has made steady advances with each improvement in telescope technology.A traditional division of observational astronomy is given by the region of the electromagnetic spectrum observed: Optical astronomy is the part of astronomy that uses optical components (mirrors, lenses and solid-state detectors) to observe light from near infrared to near ultraviolet wavelengths. Visible-light astronomy (using wavelengths that can be detected with the eyes, about 400 - 700 nm) falls in the middle of this range. Infrared astronomy deals with the detection and analysis of infrared radiation (this typically refers to wavelengths longer than the detection limit of silicon solid-state detectors, about 1 μm wavelength). The most common tool is the reflecting telescope but with a detector sensitive to infrared wavelengths. Space telescopes are used at certain wavelengths where the atmosphere is opaque, or to eliminate noise (thermal radiation from the atmosphere). Radio astronomy detects radiation of millimetre to dekametre wavelength. The receivers are similar to those used in radio broadcast transmission but much more sensitive. See also Radio telescopes. High-energy astronomy includes X-ray astronomy, gamma-ray astronomy, and extreme UV astronomy, as well as studies of neutrinos and cosmic rays.Optical and radio astronomy can be performed with ground-based observatories, because the atmosphere is relatively transparent at the wavelengths being detected. Observatories are usually located at high altitudes so as to minimise the absorption and distortion caused by the Earth's atmosphere. Some wavelengths of infrared light are heavily absorbed by water vapor, so many infrared observatories are located in dry places at high altitude, or in space.The atmosphere is opaque at the wavelengths used by X-ray astronomy, gamma-ray astronomy, UV astronomy and (except for a few wavelength ""windows"") far infrared astronomy, so observations must be carried out mostly from balloons or space observatories. Powerful gamma rays can, however be detected by the large air showers they produce, and the study of cosmic rays is a rapidly expanding branch of astronomy.For much of the history of observational astronomy, almost all observation was performed in the visual spectrum with optical telescopes. While the Earth's atmosphere is relatively transparent in this portion of the electromagnetic spectrum, most telescope work is still dependent on seeing conditions and air transparency, and is generally restricted to the night time. The seeing conditions depend on the turbulence and thermal variations in the air. Locations that are frequently cloudy or suffer from atmospheric turbulence limit the resolution of observations. Likewise the presence of the full Moon can brighten up the sky with scattered light, hindering observation of faint objects.For observation purposes, the optimal location for an optical telescope is undoubtedly in outer space. There the telescope can make observations without being affected by the atmosphere. However, at present it remains costly to lift telescopes into orbit. Thus the next best locations are certain mountain peaks that have a high number of cloudless days and generally possess good atmospheric conditions (with good seeing conditions). The peaks of the islands of Mauna Kea, Hawaii and La Palma possess these properties, as to a lesser extent do inland sites such as Llano de Chajnantor, Paranal, Cerro Tololo and La Silla in Chile. These observatory locations have attracted an assemblage of powerful telescopes, totalling many billion US dollars of investment.The darkness of the night sky is an important factor in optical astronomy. With the size of cities and human populated areas ever expanding, the amount of artificial light at night has also increased. These artificial lights produce a diffuse background illumination that makes observation of faint astronomical features very difficult without special filters. In a few locations such as the state of Arizona and in the United Kingdom, this has led to campaigns for the reduction of light pollution. The use of hoods around street lights not only improves the amount of light directed toward the ground, but also helps reduce the light directed toward the sky.Atmospheric effects (astronomical seeing) can severely hinder the resolution of a telescope. Without some means of correcting for the blurring effect of the shifting atmosphere, telescopes larger than about 15–20 cm in aperture can not achieve their theoretical resolution at visible wavelengths. As a result, the primary benefit of using very large telescopes has been the improved light-gathering capability, allowing very faint magnitudes to be observed. However the resolution handicap has begun to be overcome by adaptive optics, speckle imaging and interferometric imaging, as well as the use of space telescopes.Astronomers have a number of observational tools that they can use to make measurements of the heavens. For objects that are relatively close to the Sun and Earth, direct and very precise position measurements can be made against a more distant (and thereby nearly stationary) background. Early observations of this nature were used to develop very precise orbital models of the various planets, and to determine their respective masses and gravitational perturbations. Such measurements led to the discovery of the planets Uranus, Neptune, and (indirectly) Pluto. They also resulted in an erroneous assumption of a fictional planet Vulcan within the orbit of Mercury (but the explanation of the precession of Mercury's orbit by Einstein is considered one of the triumphs of his general relativity theory).