A Spectroscopically Confirmed Excess of 24 micron Sources in a
... confirms that it has a higher density of IR members compared to the cluster and includes bright IR sources (log(LIR )[erg s−1 ]> 45) not found in galaxy clusters at z . 0.35; and 3) there is a strong trend of decreasing 24µm fraction with increasing galaxy density, i.e. an infrared-density relation, ...
... confirms that it has a higher density of IR members compared to the cluster and includes bright IR sources (log(LIR )[erg s−1 ]> 45) not found in galaxy clusters at z . 0.35; and 3) there is a strong trend of decreasing 24µm fraction with increasing galaxy density, i.e. an infrared-density relation, ...
Astronomy Astrophysics - Niels Bohr Institutet
... would also be volume-complete to a sufficiently large distance (∼40 pc). For this, we chose the HD catalogue (Cannon & Pickering 1918–24), the only all-sky spectral catalogue then available. All A5-G0 stars brighter than mvis = 8.3, G0 stars in the interval 8.30 ≤ mvis ≤ 8.40, and all G5 or just G sta ...
... would also be volume-complete to a sufficiently large distance (∼40 pc). For this, we chose the HD catalogue (Cannon & Pickering 1918–24), the only all-sky spectral catalogue then available. All A5-G0 stars brighter than mvis = 8.3, G0 stars in the interval 8.30 ≤ mvis ≤ 8.40, and all G5 or just G sta ...
orion® starseekers - NexStar Resource Site
... Storage for programmable user defined objects; and ...
... Storage for programmable user defined objects; and ...
Comprehensive Wide-Band Magnitudes and Albedos for the Planets
... the rotation angle around the polar axis, which may influence the observed magnitude. Geophysical information can be derived from the analysis of planetary phase functions and by characterizing the varying absolute magnitudes over time. Some aspects of exo-planets can also be inferred by similar met ...
... the rotation angle around the polar axis, which may influence the observed magnitude. Geophysical information can be derived from the analysis of planetary phase functions and by characterizing the varying absolute magnitudes over time. Some aspects of exo-planets can also be inferred by similar met ...
The Milky Way as a galaxy
... to the motion of the Earth around the Sun the positions of nearby stars on the sphere change relative to those of very distant sources (e.g., extragalactic objects such as quasars). The latter therefore define a fixed reference frame on the sphere (see Fig. 2.3). In the course of a year the apparent ...
... to the motion of the Earth around the Sun the positions of nearby stars on the sphere change relative to those of very distant sources (e.g., extragalactic objects such as quasars). The latter therefore define a fixed reference frame on the sphere (see Fig. 2.3). In the course of a year the apparent ...
- National Optical Astronomy Observatory
... ! Experimentally determine the array frame rate (files / seconds). Use this information to determine the desired stepping rate for the limb guider translation stage and the number of spectral frame to collect. (Take into account that one slit width is about half an arcsecond and the diffraction limi ...
... ! Experimentally determine the array frame rate (files / seconds). Use this information to determine the desired stepping rate for the limb guider translation stage and the number of spectral frame to collect. (Take into account that one slit width is about half an arcsecond and the diffraction limi ...
instruction manual - NexStar Resource Site
... • Incredible 4°/second slew speed. • Fully enclosed motors and optical encoders for position location. • Computerized hand controller with 4,000 object data base. • Storage for programmable user defined objects; and • Many other high performance features! The StarSeeker’s deluxe features combined wi ...
... • Incredible 4°/second slew speed. • Fully enclosed motors and optical encoders for position location. • Computerized hand controller with 4,000 object data base. • Storage for programmable user defined objects; and • Many other high performance features! The StarSeeker’s deluxe features combined wi ...
Stars & Galaxies - newmanlib.ibri.org
... Different Kinds of Stars • Even a brief glance at the stars shows us that they differ in brightness. • As one looks at the stars more carefully, it becomes apparent that they are not all the ...
... Different Kinds of Stars • Even a brief glance at the stars shows us that they differ in brightness. • As one looks at the stars more carefully, it becomes apparent that they are not all the ...
A Digital Spectral Classification Atlas
... This version of the Digital Spectral Classification Atlas should really be considered a synopsis of the much more extensive Stellar Spectral Classification by R.O. Gray and C.J. Corbally, to be published by Princeton University Press in spring, 2009. Since I have borrowed extensively from that book ...
... This version of the Digital Spectral Classification Atlas should really be considered a synopsis of the much more extensive Stellar Spectral Classification by R.O. Gray and C.J. Corbally, to be published by Princeton University Press in spring, 2009. Since I have borrowed extensively from that book ...
Galaxy Sorting
... bound together by their mutual gravity. Our Sun is just one of more than one hundred billion stars that make up the Milky Way Galaxy. Note that other galaxies are very far away from us. Because of their size and distance, we cannot see any particular galaxy from more than one angle. You can't mov ...
... bound together by their mutual gravity. Our Sun is just one of more than one hundred billion stars that make up the Milky Way Galaxy. Note that other galaxies are very far away from us. Because of their size and distance, we cannot see any particular galaxy from more than one angle. You can't mov ...
A Star - Cloudy Nights
... Double Star Two thirds of all stars in the sky have a companion star. These double stars, or binary star systems have two stars that orbit around a common point. Some double stars orbit each other very quickly (once every few hours), while some orbit each other very slowly (once every few thousand y ...
... Double Star Two thirds of all stars in the sky have a companion star. These double stars, or binary star systems have two stars that orbit around a common point. Some double stars orbit each other very quickly (once every few hours), while some orbit each other very slowly (once every few thousand y ...
The science case for - Astrophysics
... technologies, will require vast increases in technology to take the next step to direct study. Each new generation of facilities is designed to answer the questions raised by the previous one, and yet most advance science by discovering the new and unexpected. As the current generation of telescopes ...
... technologies, will require vast increases in technology to take the next step to direct study. Each new generation of facilities is designed to answer the questions raised by the previous one, and yet most advance science by discovering the new and unexpected. As the current generation of telescopes ...
Galaxy formation in the Planck cosmology - II. Star
... formation occurs at a time corresponding to the mid-point of each SFH bin. To spread star formation out over the time-bin would be equivalent to using a larger number of timesteps (which we have also tested) and makes little difference except in the UV. Fig. 2 shows the difference between photometri ...
... formation occurs at a time corresponding to the mid-point of each SFH bin. To spread star formation out over the time-bin would be equivalent to using a larger number of timesteps (which we have also tested) and makes little difference except in the UV. Fig. 2 shows the difference between photometri ...
Elliptical Galaxies
... amounts of the gas and dust. As a result there are no obvious symptoms of continuing star formation: no H II regions or young star clusters. They are the simplest galactic systems comprising just a single component, relatively bright in the center but fading rapidly with increasing radius. Elliptica ...
... amounts of the gas and dust. As a result there are no obvious symptoms of continuing star formation: no H II regions or young star clusters. They are the simplest galactic systems comprising just a single component, relatively bright in the center but fading rapidly with increasing radius. Elliptica ...
CORONAL EVOLUTION OF THE SUN IN TIME: HIGH
... our solar system’s past, we have been studying the ‘‘Sun in time’’ from the early evolutionary stages on the ZAMS to the terminal stage on the main sequence, at ages of 5–10 Gyr. This study encompasses various wavelength regimes, including radio (Güdel & Gaidos 2001), optical and ultraviolet ( Dorr ...
... our solar system’s past, we have been studying the ‘‘Sun in time’’ from the early evolutionary stages on the ZAMS to the terminal stage on the main sequence, at ages of 5–10 Gyr. This study encompasses various wavelength regimes, including radio (Güdel & Gaidos 2001), optical and ultraviolet ( Dorr ...
a wide-field survey for variable stars
... formation. To further complicate the picture, infrared observations indicate that T Tauri itself is part of a multiple system and suggest that the associated Hind’s Nebula may also contain a very young stellar object. This remarkable color image spans about 4 light-years across, at the estimated dis ...
... formation. To further complicate the picture, infrared observations indicate that T Tauri itself is part of a multiple system and suggest that the associated Hind’s Nebula may also contain a very young stellar object. This remarkable color image spans about 4 light-years across, at the estimated dis ...
Sample pages 1 PDF
... wintertime sky also contains some of the most spectacular deep sky objects, of which the Orion Nebula and the Pleiades are the best known. It shouldn’t be overlooked that this is also the time of year when people give each other gifts. Quite a few budding astronomers will be testing out their first ...
... wintertime sky also contains some of the most spectacular deep sky objects, of which the Orion Nebula and the Pleiades are the best known. It shouldn’t be overlooked that this is also the time of year when people give each other gifts. Quite a few budding astronomers will be testing out their first ...
SPIRAL STRUCTURE IN THE OUTER GALACTIC
... and crowded stellar fields make membership assignments of faint stars difficult. Yet they contain massive (i.e., hot) stars that can be used to derive their parameters. The classical photometric method to address memberships in young clusters (e.g., Baume et al. 1999) simultaneously checks the consi ...
... and crowded stellar fields make membership assignments of faint stars difficult. Yet they contain massive (i.e., hot) stars that can be used to derive their parameters. The classical photometric method to address memberships in young clusters (e.g., Baume et al. 1999) simultaneously checks the consi ...
Evolution of galaxy morphology - Lecture 1 - NCRA-TIFR
... Morphological classification is at least partially affected by projection effects. If, for instance, the spatial shape of an elliptical galaxy is a triaxial ellipsoid, then the observed ellipticity will depend on its orientation with respect to the line-of-sight. Also, it will be difficult to iden ...
... Morphological classification is at least partially affected by projection effects. If, for instance, the spatial shape of an elliptical galaxy is a triaxial ellipsoid, then the observed ellipticity will depend on its orientation with respect to the line-of-sight. Also, it will be difficult to iden ...
Open clusters and associations in the Gaia era
... Not so long ago, the usual way to search for members was to select candidates based on their photometric properties and then to do follow-up observations for each object to confirm its membership based on spectroscopy and/or kinematics. Over the last ten years, full sky proper motion catalogs such a ...
... Not so long ago, the usual way to search for members was to select candidates based on their photometric properties and then to do follow-up observations for each object to confirm its membership based on spectroscopy and/or kinematics. Over the last ten years, full sky proper motion catalogs such a ...
How We See The Sky
... foci (also called radial & tangential) creating an irregular shape. Many human eyes exhibit astigmatism. ...
... foci (also called radial & tangential) creating an irregular shape. Many human eyes exhibit astigmatism. ...
LCM Analysis for PLATO 2.0
... about a complete process. This is particularly aplicable to the ongoing and planned spaceborne missions of the orbital observatories, as the method presented here provides a very fast essesment for every potenetial object in the database. The analysis has been tested for contact binaries and can be ...
... about a complete process. This is particularly aplicable to the ongoing and planned spaceborne missions of the orbital observatories, as the method presented here provides a very fast essesment for every potenetial object in the database. The analysis has been tested for contact binaries and can be ...
Stars: Intro & Classification Astronomy 1 — Elementary Astronomy LA Mission College
... We intentionally do not suggest that there is a simple mechanism for accomplishing this and we avoid the concept of filters. ...
... We intentionally do not suggest that there is a simple mechanism for accomplishing this and we avoid the concept of filters. ...
Star Clusters - Caltech Astronomy
... diagrams of two clusters will in general have the same shape, but will be shifted in magnitude by an amount equal to the difference in distance modulus between the two. There may also be additional shifts in magnitude and color index resulting from interstellar absorption. The general procedure is t ...
... diagrams of two clusters will in general have the same shape, but will be shifted in magnitude by an amount equal to the difference in distance modulus between the two. There may also be additional shifts in magnitude and color index resulting from interstellar absorption. The general procedure is t ...
Malmquist bias
The Malmquist bias is an effect in observational astronomy which leads to the preferential detection of intrinsically bright objects. It was first described in 1922 by Swedish astronomer Gunnar Malmquist (1893–1982), who then greatly elaborated upon this work in 1925. In statistics, this bias is referred to as a selection bias and affects the survey results in a brightness limited survey, where stars below a certain apparent brightness are not included. Since observed stars and galaxies appear dimmer when farther away, the brightness that is measured will fall off with distance until their brightness falls below the observational threshold. Objects which are more luminous, or intrinsically brighter, can be observed at a greater distance, creating a false trend of increasing intrinsic brightness, and other related quantities, with distance. This effect has led to many spurious claims in the field of astronomy. Properly correcting for these effects has become an area of great focus.