Global ETD Search

1	UBVRI photometry of variable red dwarf emission objects Martins, Donald Henry, January 1974 (has links) Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Bibliography: leaves 143-144. Red dwarf stars. Photometry.
2	On the reliability of 2MASS data in identifying red dwarf stars / On the reliability of Two-Micron All-Sky Survey data in identifying red dwarf stars Snyder, Lucas A. January 2004 (has links) Volume-limited samples indicate that red dwarfs are the most abundant stars in the Milky Way and account for most of its mass, despite their low individual masses. However, because of their low luminosity, they are extremely underdetected in magnitude-limited surveys. Complicating the task of identification is the fact that they have the same temperature as red giants and thus are in the same spectral class. We must therefore look for certain spectral features to differentiate between dwarfs and giants. Intermediate-to-broad-band photometry is one method that allows us to perform this task quantitatively. The 2MASS point source catalog contains data for -0.5 billion objects, including photometry in three broadband infrared filters. This paper discusses the manner in which these data can be analyzed to find red dwarfs and the success rate of such analysis. / Department of Physics and Astronomy Red dwarf stars -- Identification. Astronomical photometry. Red dwarf stars -- Spectra.
3	Accretion flows in polars Harrop-Allin, Margaret January 1999 (has links) No description available. 520 Red dwarf; White dwarf
4	In search of red dwarf stars application of three-color photometric techniques / Mason, Justin R. January 2009 (has links) Thesis (M.S.)--Ball State University, 2009. / Title from PDF t.p. (viewed on June 07, 2010). Includes bibliographical references (p. [46]).
5	Photometric parallaxes and subdwarf identification for M-type stars Thompson, Dayna L. 21 July 2012 (has links) Photometric data on the Kron-Cousins photometric system have been obtained for 118 new late K to middle M-type stars with known distances. These data have been used to obtain absolute red magnitudes, to construct a color-magnitude diagram, and to compute a polynomial function for disk dwarf stars in the color range 1.5 ≤ R-I < 2.0, which can be used to compute absolute red magnitudes to be used for photometric parallaxes. Such photometric parallaxes allow new stellar distance estimations that are essential when modeling the spatial distribution of stars in our Galaxy. This is especially important for M-type stars, as they make up more than half of the mass of the Milky Way. Intermediate-band CaH observations have also been obtained in an ongoing effort to distinguish stellar luminosity classes and populations; R-L and R-I colors are used to identify possible subdwarf stars. A total of seven possible new subdwarfs and three previously known subdwarfs have been identified with this method. / Department of Physics and Astronomy Parallax -- Stars Astronomical photometry M stars -- Magnitudes Red dwarf stars
6	An analysis of luminosity classification of red stars using 2MASS photometric data to create an unbiased sample of red dwarf stars Furiak, Nicolas M. January 2002 (has links) Study determined if 2MASS photometric data are reliable for luminosity classification using JHK plots of Reid and Hawley (2001). Effects of interstellar reddening on the placement of giant and dwarf data on the JIIK plot were analyzed. Dwarfs (N=54) were selected from Hipparchos and the 2MASS data reduced to an H-K range of 0.14-0.40. A disk dwarf region was identified using linear regression on the low space velocity stars. Giants selected from Volume 5 of the Michigan Catalogue of HD stars and SAG stars classified at Ball State University. They yielded 304 individual giants and 13 matches in the 0.14-0.40 H-K range respectively. The 2MASS data was reliable for luminosity classification of the SAGBSU giants. The classification of the Michigan giants was not possible due to interstellar reddening and the likely presence of faint giant companions. / Department of Physics and Astronomy Red dwarf stars. Red giants. Stars -- Classification. Stars -- Luminosity function.
7	In search of red dwarf stars : application of three-color photometric techniques Mason, Justin R. January 2009 (has links) This paper presents the photometric luminosity classification of M dwarfs in Kaptyn’s Selected Area 124 (SA124). This project is part of an ongoing program at Ball State University to use R, I, and CaH photometry in an attempt to probe low luminosity star contributions to the luminosity function. Data is taken at the Southeastern Association for Research in Astronomy (SARA) telescope located at Kitt Peak, Arizona. With a limiting magnitude of R=15.0, we have observed ~75% of a full square degree in SA124 and have detected 19 M dwarf candidates, which are then confirmed using matched 2MASS J, H, and K magnitudes. We present the detections of 19 ±4.4 M dwarfs observed in SA124. The current estimates of our luminosity function are consistent with those previously determined for the galactic plane. / Department of Physics and Astronomy Red dwarf stars--Identification Stars--Luminosity function Astronomical photometry
8	Luminosity classification of red stars and distances to nearby red dwarfs Maupin, Richard E. January 2002 (has links) This investigation in the 24 Kapteyn Selected Areas along the celestial equator examined 21 red dwarf stars identified in an objective-prism survey. These stars were classified as red dwarf stars using light at wavelengths between 5800 A and 6800 A. Using calcium-hydride-based luminosity classification, this study found 13 of these stars to be red giant stars, and only 6 stars were found to be red dwarfs. One star was determined to be warm star. One star was not clearly distinguishable as a dwarf or giant. Distance calculations for the red dwarf stars found that these stars lie within 40 parsecs of the sun. / Department of Physics and Astronomy Stars -- Luminosity function. Red dwarf stars. Luminosity distance. Parallax -- Stars.
9	The impact of abundance variations on photometric luminosity indicators DeCocq, John D. January 1996 (has links) Red dwarf stars are one proposed solution to the dark matter problem in the Milky Way Galaxy These cool, low luminosity stars are difficult to detect and segregate in surveys. This study utilizes photometric data obtained on the Kron-Cousins photometric system to develop criteria that classifies stars as red. Two of the color indices are then used to create a two-color diagram to allow separation of giant and dwarf stars. An algorithm based on calculated equations is provided to separate the giant and dwarf stars after detection. A third class of stars, subdwarfs, is addressed as a potential problem in future surveys. Some suggestions for detecting and removing these contaminating stars from the data are offered. Finally, a colormagnitude diagram is developed for red dwarf stars with KronCousins photometry. This curve allows for fairly accurate determination of photometric parallaxes for the red dwarf stars.An attempt was made to segregate the red dwarfs into velocity classes prior to calibrating the color-magnitude diagram. It was found that this approach offered no additional useful information. / Department of Physics and Astronomy Red dwarf stars. Stars -- Masses. Astronomical photometry. Stars -- Color.
10	Spectroscopic characterization of transiting exoplanets : A study of the possibility to detect atmospheres around exoplanets using SIMPLE Waldén, Pierre, Aronson, Erik January 2011 (has links) This report describes simulations of observations with the near-infrared high-resolution spectrometer SIMPLE that is proposed to the ESO telescope E-ELT. We simulate M4 and G2 stars with transiting Earth-like planets and the goal is to distinguish spectral features originating from the atmosphere of the exoplanet. Noise levels of different magnitudes are added to the simulations and the minimal signal-to-noise required for detection of the atmosphere is estimated. Our conclusion is that detection of atmospheric features looks promising using this setup. exoplanet atmosphere spectrum extra solar planet spectroscopy SIMPLE E-ELT ESO spectrometer telescope spectral features noise signal to noise S/N planet star red dwarf atmospheric features Super-Earth Earth-like Astronomy Astronomi

Search results