ASTR2100 - Saint Mary's University | Astronomy & Physics
... The relationship is not zeroed to the Sun, since solar metallicity is calculated to have been reached at an age of ~2.5 109 years. [Fe/H] = log[(Fe/H)/(F/H)], i.e. 2 the solar metallicity is equivalent to [Fe/H] = +0.30. Of the main components of the Galaxy, there are at least two components of ...
... The relationship is not zeroed to the Sun, since solar metallicity is calculated to have been reached at an age of ~2.5 109 years. [Fe/H] = log[(Fe/H)/(F/H)], i.e. 2 the solar metallicity is equivalent to [Fe/H] = +0.30. Of the main components of the Galaxy, there are at least two components of ...
PH607 – Galaxies
... used for calibrating distances and also that what Hubble thought were bright stars in distant galaxies were actually H II regions. Throughout the 20th century we found evidence for H0 in the range 50 -100 km/s/Mpc, depending on the method employed. So, we took h = H/100 km/s/Mpc in all our formula t ...
... used for calibrating distances and also that what Hubble thought were bright stars in distant galaxies were actually H II regions. Throughout the 20th century we found evidence for H0 in the range 50 -100 km/s/Mpc, depending on the method employed. So, we took h = H/100 km/s/Mpc in all our formula t ...
Examining the M67 Classification as an Open Cluster
... bound clusters. In Ref. [15], it has pointed out that because of the scattering of stars in clusters on the stars in the galactic field the total internal energy of a cluster should rise, ultimately leading to a complete breakup of the cluster. It turned out that the characteristic time for this pro ...
... bound clusters. In Ref. [15], it has pointed out that because of the scattering of stars in clusters on the stars in the galactic field the total internal energy of a cluster should rise, ultimately leading to a complete breakup of the cluster. It turned out that the characteristic time for this pro ...
Astronomical Distance Determination • etc.
... Size of galaxy determined by how far away we could see stars 1912 - Henrietta Leavitt discovers P-L relation for Cepheid variables 1913 - Ejnar Hertzsprung calibrates the relation using nearby (Type I Cepheids) but ignored reddening. 1918 - Shapley determines distance to galactic center by getting d ...
... Size of galaxy determined by how far away we could see stars 1912 - Henrietta Leavitt discovers P-L relation for Cepheid variables 1913 - Ejnar Hertzsprung calibrates the relation using nearby (Type I Cepheids) but ignored reddening. 1918 - Shapley determines distance to galactic center by getting d ...
Universe 8e Lecture Chapter 24 Galaxies
... cluster of galaxies is not large enough to account for the observed motions of the galaxies; a large amount of unobserved mass must also be present. This situation is called the dark-matter problem. Hot intergalactic gases in rich clusters account for a small part of the unobserved mass. These gases ...
... cluster of galaxies is not large enough to account for the observed motions of the galaxies; a large amount of unobserved mass must also be present. This situation is called the dark-matter problem. Hot intergalactic gases in rich clusters account for a small part of the unobserved mass. These gases ...
19 The Milky Way Galaxy
... No evidence so far, but they are looking for them using the Large Hadron Collider ...
... No evidence so far, but they are looking for them using the Large Hadron Collider ...
question - UW Canvas
... a. The locations or coordinates on the celestial sphere where the clusters are located. b. How fast each cluster is moving relative to Earth; i.e., spectral redshifts or blueshifts. c. The value of Hubble’s constant by fitting a slope to the main sequence. d. The approximate masses of main sequence ...
... a. The locations or coordinates on the celestial sphere where the clusters are located. b. How fast each cluster is moving relative to Earth; i.e., spectral redshifts or blueshifts. c. The value of Hubble’s constant by fitting a slope to the main sequence. d. The approximate masses of main sequence ...
26.4 Groups of Stars
... Most stars occur in groups of two or more. • A star system is a group of two or more stars that are held together by gravity. • A star system with two stars is called a binary star. The two stars orbit each other. ...
... Most stars occur in groups of two or more. • A star system is a group of two or more stars that are held together by gravity. • A star system with two stars is called a binary star. The two stars orbit each other. ...
Some Examples of Virtual Observatory Enabled Science What Are the Some Distinguishing
... • Only ~ 10 - 20% of galaxies live in clusters, but it is hard to draw the line between groups and clusters, and at least ~50% of all galaxies are in clusters or groups • Clusters have higher densities than groups, contain a majority of E’s and S0’s while groups are dominated by spirals • Interestin ...
... • Only ~ 10 - 20% of galaxies live in clusters, but it is hard to draw the line between groups and clusters, and at least ~50% of all galaxies are in clusters or groups • Clusters have higher densities than groups, contain a majority of E’s and S0’s while groups are dominated by spirals • Interestin ...
Part 2 - Aryabhat
... All stars shine but none do it like Sirius, the brightest star in the night sky. Aptly named, Sirius comes from the Greek word Seirius, meaning, "searing" or "scorching." Blazing at a visual magnitude of –1.42, it is twice as bright as any other star in our sky. Sirius resides in the constellation C ...
... All stars shine but none do it like Sirius, the brightest star in the night sky. Aptly named, Sirius comes from the Greek word Seirius, meaning, "searing" or "scorching." Blazing at a visual magnitude of –1.42, it is twice as bright as any other star in our sky. Sirius resides in the constellation C ...
PH607lec12
... Can define a Hubble length: c / H0 ~ 4000 Mpc at which this expression for the recession velocity extrapolates to the speed of light - more detailed relativistic treatment is needed for distances of this order. Can also define a Hubble time: 1 / H0 ~ 1010 years …this is to order of magnitude the age ...
... Can define a Hubble length: c / H0 ~ 4000 Mpc at which this expression for the recession velocity extrapolates to the speed of light - more detailed relativistic treatment is needed for distances of this order. Can also define a Hubble time: 1 / H0 ~ 1010 years …this is to order of magnitude the age ...
CCD PHOTOMETRY OF OPEN STAR CLUSTER M67
... values have been reduced and calibrated so thoroughly and in the correct manner that the resulting diagrams show marked and clearly defined main sequences. On the colourmagnitude diagrams can be seen the main sequence directed from the lower right to upper left corner, which means that it is a very ...
... values have been reduced and calibrated so thoroughly and in the correct manner that the resulting diagrams show marked and clearly defined main sequences. On the colourmagnitude diagrams can be seen the main sequence directed from the lower right to upper left corner, which means that it is a very ...
12 The Milky Way - Journigan-wiki
... Population I and II Groups Population I and II stars differ in almost every respect: age, color, location, motion and composition. Population I stars are younger, averaging from 106 to 109 years old. Most are blue and lie in the galactic disk following approximately circular orbits. Their compositi ...
... Population I and II Groups Population I and II stars differ in almost every respect: age, color, location, motion and composition. Population I stars are younger, averaging from 106 to 109 years old. Most are blue and lie in the galactic disk following approximately circular orbits. Their compositi ...
harrold_kajubi_astro1
... Mees Telescope with Charge-Coupled Device (CCD) Camera Photometry with ATV ...
... Mees Telescope with Charge-Coupled Device (CCD) Camera Photometry with ATV ...
Brown et al. 2008 Studying Resolved Stellar
... JWST will observe the birth of galaxies at high redshift, but it will complement that research by reconstructing the star formation histories of nearby galaxies, using multiband photometry of their resolved stellar populations. In a complex population hosting a mix of chemical abundances and ages, a ...
... JWST will observe the birth of galaxies at high redshift, but it will complement that research by reconstructing the star formation histories of nearby galaxies, using multiband photometry of their resolved stellar populations. In a complex population hosting a mix of chemical abundances and ages, a ...
Measuring the Milky Way
... These objects are very close to the Galactic center. The orbit on the right is the best fit; it assumes a central black hole of 3.7 million solar masses. ...
... These objects are very close to the Galactic center. The orbit on the right is the best fit; it assumes a central black hole of 3.7 million solar masses. ...
1/2016
... Description: Delta Cephei is the prototype of the Cepheid class of variable stars. With a change in visual magnitude of 3.5 to 4.4, delta Cephei’s entire range of variability can be observed with the unaided eye. Its period of 5.366 days makes it an attractive candidate for anyone anxious to obtain ...
... Description: Delta Cephei is the prototype of the Cepheid class of variable stars. With a change in visual magnitude of 3.5 to 4.4, delta Cephei’s entire range of variability can be observed with the unaided eye. Its period of 5.366 days makes it an attractive candidate for anyone anxious to obtain ...
1 Pau Amaro Seoane - modest 15-s
... radii between 10 to 100 pc they are more than a factor 1000 denser than dwarf galaxies of the same mass. They also show evidence for elevated mass-to-light ratios, which could be due to the presence of massive black holes or unusual stellar IMFs as a result of their extreme densities. While the firs ...
... radii between 10 to 100 pc they are more than a factor 1000 denser than dwarf galaxies of the same mass. They also show evidence for elevated mass-to-light ratios, which could be due to the presence of massive black holes or unusual stellar IMFs as a result of their extreme densities. While the firs ...
ppt document - FacStaff Home Page for CBU
... Way. By looking in the infrared (which is not scattered as much as visible light by the dust and gas), we see that we are not in the center of the disk, but somewhere away from the center. The approximate size of the Milky Way appears to be about 100,000 light years across and 2,000 light years thic ...
... Way. By looking in the infrared (which is not scattered as much as visible light by the dust and gas), we see that we are not in the center of the disk, but somewhere away from the center. The approximate size of the Milky Way appears to be about 100,000 light years across and 2,000 light years thic ...
Slide 1
... 5. Distance, age, metallicity, extinction, and differential reddening estimates 6. Uncertainties in evolutionary tracks, isochrones;Teff scale: especially for very young clusters (PMS stars) and low-mass stars, but to some extent for all cluster studies. Coupled to 5 above. Nearly all these uncert ...
... 5. Distance, age, metallicity, extinction, and differential reddening estimates 6. Uncertainties in evolutionary tracks, isochrones;Teff scale: especially for very young clusters (PMS stars) and low-mass stars, but to some extent for all cluster studies. Coupled to 5 above. Nearly all these uncert ...
The Milky Way
... • The gravitational field of this spiral pattern causes stars and gas to slow down near the arm • This compresses the interstellar clouds, triggering the formation of stars • The entire arm pattern rotates around the Milky Way once every 500 million years ...
... • The gravitational field of this spiral pattern causes stars and gas to slow down near the arm • This compresses the interstellar clouds, triggering the formation of stars • The entire arm pattern rotates around the Milky Way once every 500 million years ...
Chapter 1 Introduction
... tend to show little or no hydrogen, and are therefore classed as Type Ib (containing helium lines) or Type Ic (containing no helium lines). e mass of the ejecta in these supernovae is small (and may be almost non-existent in the case of ultra-stripped Type Ic supernovae), and therefore so is the tot ...
... tend to show little or no hydrogen, and are therefore classed as Type Ib (containing helium lines) or Type Ic (containing no helium lines). e mass of the ejecta in these supernovae is small (and may be almost non-existent in the case of ultra-stripped Type Ic supernovae), and therefore so is the tot ...
Globular cluster
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is derived from the Latin globulus—a small sphere. A globular cluster is sometimes known more simply as a globular.Globular clusters, which are found in the halo of a galaxy, contain considerably more stars and are much older than the less dense galactic, or open clusters, which are found in the disk. Globular clusters are fairly common; there are about 150 to 158 currently known globular clusters in the Milky Way, with perhaps 10 to 20 more still undiscovered. These globular clusters orbit the Galaxy at radii of 40 kiloparsecs (130,000 light-years) or more. Larger galaxies can have more: Andromeda, for instance, may have as many as 500. Some giant elliptical galaxies, particularly those at the centers of galaxy clusters, such as M87, have as many as 13,000 globular clusters.Every galaxy of sufficient mass in the Local Group has an associated group of globular clusters, and almost every large galaxy surveyed has been found to possess a system of globular clusters. The Sagittarius Dwarf galaxy and the disputed Canis Major Dwarf galaxy appear to be in the process of donating their associated globular clusters (such as Palomar 12) to the Milky Way. This demonstrates how many of this galaxy's globular clusters might have been acquired in the past.Although it appears that globular clusters contain some of the first stars to be produced in the galaxy, their origins and their role in galactic evolution are still unclear. It does appear clear that globular clusters are significantly different from dwarf elliptical galaxies and were formed as part of the star formation of the parent galaxy rather than as a separate galaxy. However, recent conjectures by astronomers suggest that globular clusters and dwarf spheroidals may not be clearly separate and distinct types of objects.