Results 11 to 20 of about 995 (187)

A geometric framework for outlier detection in high‐dimensional data

WIREs Data Mining and Knowledge Discovery, Volume 13, Issue 3, May/June 2023., 2023
A geometric framework exploiting the metric structure of a data set allows to (1) conceptualize outlier detection on a general level and (2) to conduct outlier detection in a principled and canonical way in very different high‐dimensional and/or non‐tabular data types such as functions (A.1), graphs (B.1), or images (C.1).
Moritz Herrmann, Florian Pfisterer, Fabian Scheipl   +2 more
wiley   +1 more source

RR Lyrae variables in Galactic globular clusters [PDF]

Astronomy & Astrophysics, 2004
We present theoretical predictions concerning horizontal branch stars in globular clusters, including RR Lyrae variables, as derived from synthetic procedures collating evolutionary and pulsational constraints. On this basis, we explore the predicted behavior of the pulsators as a function of the horizontal branch morphology and over the metallicity ...
Cassisi, S., Castellani, M., Caputo, F., Castellani, V.   +3 more
openaire   +2 more sources

RR Lyrae Stars and Anomalous Cepheids as Population Tracers in Local Group Galaxies

Universe, 2022
We discuss the use and importance of pulsating variable stars as population tracers in Local Group galaxies. Among bright variable crossing the classical instability strip, we mostly focus on RR Lyrae stars and Anomalous Cepheids.
Matteo Monelli, Giuliana Fiorentino
doaj   +1 more source

The Distances to RR Lyrae Variables [PDF]

Symposium - International Astronomical Union, 1988
Of all the different methods employed to estimate the mean absolute magnitude of RR Lyrae variables, only an analysis of the Baade-Wesselink type can determine this quantity directly. The distance to a globular cluster can therefore be measured by determining <MV>RR for that cluster instead of being forced to assume that <MV>RR is the same ...
Rodney V. Jones, Bruce W. Carney, David W. Latham, Robert L. Kurucz   +3 more
openaire   +1 more source

Modulation of the Blazhko Cycle in LS Her

The Astronomical Journal, 2023
We present analysis of the RR Lyrae star, LS Her, and confirm the previously reported modulation to its Blazhko cycles. We performed Fourier analysis on two sectors (Sector 24 and 25) of data from the Transiting Exoplanet Survey Satellite (TESS) spanning
Ronald Wilhelm, Kenneth Carrell, Hannah H. Means, Adam Popowicz, Krzysztof Bernacki, Mariusz Frąckiewicz, Marek Szczepański, Adam Dustor, Jaylon Lockett, Jill Taylor, Stasha Youngquist   +10 more
doaj   +1 more source

RR Lyrae and BL Herculis variables [PDF]

Space Science Reviews, 1980
AbstractThe RR Lyrae variables are currently believed to have masses between about 0.5 and 0.8 M⊙, effective surface temperatures between 6350 and 7500K, radii from about 4.0 to 6.0 R⊙ and luminosities between log L/L⊙ of 1.5 and 2.0. Since they are found in population II locations, they generally have Y = 0.3 and Z = 10−3 , but there are exceptions ...
openaire   +1 more source

Semiconvection and the RR Lyrae Variables [PDF]

International Astronomical Union Colloquium, 1973
Theoretical computations (Hoyle and Schwarzschild, 1955; Faulkner, 1966; Iben and Rood, 1970; Demarque and Mengel, 1971a, b) have identified the horizontal-branch stars in globular clusters with the evolution phase in which helium burns within a convective core and hydrogen burns in a shell outside the convective core. Most computations for such double-
A. V. Sweigart, P. Demarque
openaire   +1 more source

Metallicity Effects on RR Lyrae Variables [PDF]

The Astrophysical Journal, 1996
postscript file of 14 pages and 4 figures; for any problem please write to bono@oat.ts.astro ...
Bono, G., Incerpi, R., Marconi, M.
openaire   +2 more sources

RR Lyrae Variables in NGC 7006 [PDF]

International Astronomical Union Colloquium, 1995
AbstractB and V CCD frames of the globular cluster NGC 7006 have been obtained to study the period change rates and determine photometric colours for the RR Lyr variables.
Amelia Wehlau, Robert W. Slawson, James M. Nemec, Steve Butterworth   +3 more
openaire   +1 more source

PLATO as it is: A legacy mission for Galactic archaeology

Astronomische Nachrichten, Volume 338, Issue 6, Page 644-661, July 2017., 2017
Deciphering the assembly history of the Milky Way is a formidable task, which becomes possible only if one can produce high‐resolution chrono‐chemo‐kinematical maps of the Galaxy. Data from large‐scale astrometric and spectroscopic surveys will soon provide us with a well‐defined view of the current chemo‐kinematical structure of the Milky Way, but it ...
A. Miglio, C. Chiappini, B. Mosser, G. R. Davies, K. Freeman, L. Girardi, P. Jofré, D. Kawata, B. M. Rendle, M. Valentini, L. Casagrande, W. J. Chaplin, G. Gilmore, K. Hawkins, B. Holl, T. Appourchaux, K. Belkacem, D. Bossini, K. Brogaard, M.‐J. Goupil, J. Montalbán, A. Noels, F. Anders, T. Rodrigues, G. Piotto, D. Pollacco, H. Rauer, C. Allende Prieto, P. P. Avelino, C. Babusiaux, C. Barban, B. Barbuy, S. Basu, F. Baudin, O. Benomar, O. Bienaymé, J. Binney, J. Bland‐Hawthorn, A. Bressan, C. Cacciari, T. L. Campante, S. Cassisi, J. Christensen‐Dalsgaard, F. Combes, O. Creevey, M. S. Cunha, R. S. Jong, P. Laverny, S. Degl'Innocenti, S. Deheuvels, É. Depagne, J. Ridder, P. Di Matteo, M. P. Di Mauro, M.‐A. Dupret, P. Eggenberger, Y. Elsworth, B. Famaey, S. Feltzing, R. A. García, O. Gerhard, B. K. Gibson, L. Gizon, M. Haywood, R. Handberg, U. Heiter, S. Hekker, D. Huber, R. Ibata, D. Katz, S. D. Kawaler, H. Kjeldsen, D. W. Kurtz, N. Lagarde, Y. Lebreton, M. N. Lund, S. R. Majewski, P. Marigo, M. Martig, S. Mathur, I. Minchev, T. Morel, S. Ortolani, M. H. Pinsonneault, B. Plez, P. G. Prada Moroni, D. Pricopi, A. Recio‐Blanco, C. Reylé, A. Robin, I. W. Roxburgh, M. Salaris, B. X. Santiago, R. Schiavon, A. Serenelli, S. Sharma, V. Silva Aguirre, C. Soubiran, M. Steinmetz, D. Stello, K. G. Strassmeier, P. Ventura, R. Ventura, N. A. Walton, C. C. Worley   +104 more
wiley   +1 more source