3 edition of UV-bright stars in globular clusters found in the catalog.
UV-bright stars in globular clusters
|Statement||by Wayne B. Landsman.|
|Series||NASA contractor report -- NASA CR-189324.|
|Contributions||United States. National Aeronautics and Space Administration.|
|The Physical Object|
Introduction  Naming of pulsars in globular clusters  Individual clusters  47 Tucanae . The first two pulsars, PSR BA and BB were reported by Ables et al. () and Ables et al. () and had a dispersion measure of 65cm-3 pc, but were subsequently shown to be false candidates. This was quickly followed by Manchester et al. () (Manchester et al. . Elliptical galaxies and globular clusters have a lot in common. There is no gas or dust in a globular cluster, and the stars are old. In fact, globular clusters may be the some of the oldest objects in the universe. The big difference is size! Globular clusters contain hundreds of thousands or millions of stars.
Messier Messier 55 (also known as M55 or NGC ) is a globular cluster in the constellation Sagittarius. It was discovered by Nicolas Louis de Lacaille in J while observing from what today is South llation: Sagittarius. Globular clusters are composed of Population II objects (i.e., old stars). The brightest stars are the red giants, bright red stars with an absolute magnitude of −2, about times the Sun’s brightness or luminosity.
27 works Search for books with subject Globular clusters. Search. UV-bright stars in globular clusters Wayne B. Landsman Read. Read. Read. Read. Borrow. Read. Globular clusters NATO Advanced Study Institute Read. Dynamical evolution of dense stellar systems International Astronomical Uni. Star Generations. It had been thought that NGC , like typical globular clusters, contains only one generation of stars formed simultaneously from the same material. In , a team of astronomers led by Giampaolo Piotto of the University of Padua in Italy investigated Hubble Space Telescope images of NGC taken in and with Hubble's Advanced Constellation: Carina.
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While globular clusters with a populous EHB are ex-pected to be deﬁcient in post-AGB stars, they should show a substantial population of less luminous ( post-early AGB stars.
The population of post-EHB stars is expected to be about 15–20 % of the population. Blue horizontal branch and UV bright stars in several globular clusters are analysed spectroscopically and the results are compared with predictions of stellar evolutionary theory. We find that the distribution of temperatures and surface gravities of the blue HB stars may be explained by the effects of deep mixing.
Abstract. This paper highlights globular cluster studies with Ultraviolet Imaging Telescope (UIT) in three areas: the discrepancy between observed ultraviolet HB magnitudes and predictions of theoretical HB models; the discovery of two hot subdwarfs in NGCa globular not previously known to contain such stars; and spectroscopic follow up of newly identified UV-bright stars Cited by: 1.UV-bright stars in globular clusters [microform] / by Wayne B.
Landsman National Aeronautics and Space Administration [Washington, D.C. Wikipedia Citation Please see Wikipedia's template documentation for further citation fields that may be required. We have obtained medium-resolution spectra of seven UV-bright stars discovered on images of four southern globular clusters obtained with the Ultraviolet.
Blue horizontal branch and UV bright stars in several globular clusters are analysed spectroscopically and the results are compared with predictions of stellar. Abstract. We have obtained medium-resolution spectra of seven UV-bright stars discovered on images of four southern globular clusters obtained with the Ultraviolet Imaging Telescope (UIT).
Effective temperatures, surface gravities and helium abundances are derived from LTE and non-LTE model atmosphere fits. Abstract: We have performed a UV-bright stars in globular clusters book of the UV-bright population in 78 globular clusters using wide-field UV telescopes.
This population includes a variety of phases of post-horizontal branch (HB) evolution, including hot post-asymptotic giant branch (AGB) stars, and post-early AGB : S. Moehler, W. Landsman, T. Lanz, M. Miller Bertolami. UV bright stars can be found in colour-magnitude diagrams of globular clusters, lying above the horizontal branch and to the blue of the giant branch.
They are mostly post-AGB stars evolving to white dwarfs. Recent analyses of field pop. The origins, evolution and fates of the various stars and star clusters in the Galaxy are surveyed. The structure and composition of the Galaxy is discussed, and the Hyades cluster is presented as a model for other star clusters located further from the sun.
Consideration is given to the chemical compositions of stars in various stages of evolution, and to the physics of this Cited by: 6. UV-bright stars in globular clusters (SuDoc NAS ) [Wayne B.
Landsman] on *FREE* shipping on qualifying : Wayne B. Landsman. Get this from a library. UV-bright stars in globular clusters. [Wayne B Landsman; United States. National Aeronautics and Space Administration.]. Moehler et al.: Hot UV bright stars in globular clusters During the two ﬂights of the ASTRO observatory in andthe Ultraviolet Imaging Telescope (UIT, Stecher et al.
) was used to obtain ultraviolet (˘ A) images of˚ 14 globular clusters. The solar-blind detectors on UIT suppress.
We have obtained medium-resolution spectra of seven UV-bright stars discovered on images of four southern globular clusters obtained with the Ultraviolet Imaging Telescope (UIT). Effective temperatures, surface gravities and helium abundances are derived from LTE and non-LTE model atmosphere fits.
It is not a field guide as the other ones are meant to be. Yet the information contained is invaluable to all star cluster (and this book, as do the others cover both open and globular clusters) observers.
A virtually complete list of all the cataloged star clusters and suspected star clusters as well as several asterisms is covered/5(7).
Download Citation | Hot UV-bright stars of galactic globular clusters | Context. We have performed a census of the UV-bright population in 78 globular clusters using wide. CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): Abstract.
Two UV brights stars in globular clusters, ROA (ω Cen) and Barnard 29 (M 13) are analysed from highresolution UV and optical spectra. The main aim is the measurement of iron abundances from UV spectra obtained with the HST-GHRS. In addition atmospheric parameters and. Globular clusters are extremely luminous objects.
Their mean luminosity is the equivalent of approximat Suns. The most luminous are 50 times brighter. The brightest stars are the red giants, bright red stars with an absolute magnitude of −2, about times the Sun’s brightness, or luminosity.
Milky WayEdit. These are globular clusters within the halo of the Milky Way galaxy. The diameter is in minutes of arc as seen from Earth.
For reference, the J epoch celestial coordinates of the Galactic Center are R.A. 17 h 45 m s, Dec. −29° 00′ ″. A high proportion of globular clusters are located in. A globular cluster is a spherical collection of stars that orbits a galactic core. 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. Occasionally, a globular cluster is known simply as a globular. Globular clusters. Messier 22 or M22, also known as NGCis an elliptical globular cluster of stars in the constellation Sagittarius, near the Galactic bulge region.
It is one of the brightest globulars that is visible in the night llation: Sagittarius.individual: NGC – ultraviolet: stars 1. Introduction Theterm“UVbrightstars”wasintroducedbyZinnetal.() for stars in globular clusters that lie above the horizontal branch (HB) and are bluer than red giants.
The name resulted from the fact that in the U band these stars were brighter than all other cluster stars.Oddly behaving star reveals a black hole hiding in a globular cluster, a first By the way, it’s also the first stellar-mass black hole ever found based on its gravitational pull.