Journal articles: 'RR'

1

Sekula, Allan, Cyril Béghin, and D'Allan Sekula. "RR JB." Vertigo 36, no. 2 (2009): 108. http://dx.doi.org/10.3917/ver.036.0108.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Saintamand, Alexis, Nour Ghazzaui, Hussein Issaoui, and Yves Denizot. "3’RR." médecine/sciences 33, no. 11 (November 2017): 963–70. http://dx.doi.org/10.1051/medsci/20173311013.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Kolenberg, Katrien, Robert L. Kurucz, Robert Stellingwerf, James M. Nemec, Paweł Moskalik, Luca Fossati, and Thomas G. Barnes. "RR Lyrae studies with Kepler: showcasing RR Lyr." Proceedings of the International Astronomical Union 9, S301 (August 2013): 257–60. http://dx.doi.org/10.1017/s1743921313014415.

Full text

Abstract:

AbstractFour years into the Kepler mission, an updated review on the results for RR Lyrae stars is in order. More than 50 RR Lyrae stars in the Kepler field are observed with Kepler and each one of them can provide us with new insight into this class of pulsating stars. Ground-based spectroscopy of the Kepler targets allows us to narrow down their physical parameters. Previously, we already reported a 50% occurrence rate of modulation in the RRab stars, a large variety of modulation behavior, period doubling in several Blazhko stars, the detection of higher- overtone radial modes, probable non-radial modes and new types of multiple-mode RR Lyrae pulsators, among both the RRab and the RRc stars. In addition, the quasi-continuous photometry obtained over several years with Kepler allows one to observe changes in Blazhko behavior and additional longer cycles. These observations have sparked new theoretical modelling efforts. In this short paper we showcase RR Lyr itself. The star has been observed with Kepler in short cadence, and some remarkable features of its pulsation behavior are unveiled in this long-studied prototype, through the Kepler photometry and additional spectroscopic data.

APA, Harvard, Vancouver, ISO, and other styles

4

ZAREBA, WOJCIECH. "QT‐RR Slope:." Journal of Cardiovascular Electrophysiology 14, no. 3 (March 2003): 234–35. http://dx.doi.org/10.1046/j.1540-8167.2003.02567.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Bono, G., and M. Marconi. "RR Lyrae variables." Symposium - International Astronomical Union 189 (1997): 305–10. http://dx.doi.org/10.1017/s0074180900116821.

Full text

Abstract:

On the basis of a historical overview we outline the relevant results which allowed to approach on firm basis the physical mechanisms which govern the radial pulsation of RR Lyrae variables, revealing the astrophysical parameters which account for their limiting amplitude pulsational behavior.

APA, Harvard, Vancouver, ISO, and other styles

6

Malik, Marek. "QT/RR hysteresis." Journal of Electrocardiology 47, no. 2 (March 2014): 236–39. http://dx.doi.org/10.1016/j.jelectrocard.2014.01.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Ya’u, Badamasi Imam, Azlin Nordin, and Norsaremah Salleh. "Investigation of Requirements Reuse (RR) Challenges and Existing RR Approaches." Advanced Science Letters 23, no. 5 (May 1, 2017): 4101–5. http://dx.doi.org/10.1166/asl.2017.8232.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Han, Ha-si-ao-qi-er, Chun-Yang Han, Zhen-Bang Xu, Ming-Chao Zhu, Yang Yu, and Qing-Wen Wu. "Kinematics analysis and testing of novel 6-P-RR-R-RR parallel platform with offset RR-joints." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 10 (December 11, 2018): 3512–30. http://dx.doi.org/10.1177/0954406218817001.

Full text

Abstract:

This paper presents a novel six-degree-of-freedom (6-DOF) parallel platform that is used as the third mirror adjustment system of a large space telescope. In order to meet the design requirements of high precision, a large load–size ratio, and high stiffness in both the transverse and the vertical directions, the parallel platform is designed to be a 6-P-RR-R-RR structure via use of offset RR-joints. The inverse kinematics problem of the designed platform with offset RR-joints is much more complicated than that of a parallel platform with common universal joints owing to the presence of joint-dependent variables in the former problem. In this study, inverse kinematics of the designed parallel platform is mathematically modeled and the Newton–Raphson numerical iterative computation is performed. The accuracy and effectiveness of the proposed mathematical approach are verified by numerical co-simulations using MATLAB and ADAMS. The initial position of the platform is determined by a precision measuring arm. A test system is constructed, and then inverse kinematics solution, resolutions and adjusting steps accuracies of the platform are tested using grating length gauges. Motion strokes of the parallel mechanism are measured using laser tracker.

APA, Harvard, Vancouver, ISO, and other styles

9

Avadayappan, S., M. Bhuvaneshwari, and S. Vimalajenifer. "rr-SEQUENCE PRODUCT GRAPHS." Advances in Mathematics: Scientific Journal 9, no. 3 (June 4, 2020): 927–36. http://dx.doi.org/10.37418/amsj.9.3.18.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Gaylor, SK, JA Ryan, ME Sanders, GS Hughes, TV Ringer, MJ DeLoof, GE Winterrowd, and SF Francom. "Reply to RR Watson." American Journal of Clinical Nutrition 54, no. 3 (September 1, 1991): 610. http://dx.doi.org/10.1093/ajcn/54.3.610.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Nair, RR, and Gurleen Nanra. "Interview with RR Nair." NHRD Network Journal 9, no. 3 (July 2016): 7–10. http://dx.doi.org/10.1177/0974173920160303.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Yoshigoe, Kenji, Ken Christensen, and Allen Roginsky. "Performance evaluation of new scheduling methods for the RR/RR CICQ switch." Computer Communications 28, no. 4 (March 2005): 417–28. http://dx.doi.org/10.1016/j.comcom.2004.08.021.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Dombrovsky, Aviv, Irena Sobolev, Nor Chejanovsky, and Benajmin Raccah. "Characterization of RR-1 and RR-2 cuticular proteins from Myzus persicae." Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 146, no. 2 (February 2007): 256–64. http://dx.doi.org/10.1016/j.cbpb.2006.11.013.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Milman, Vitali, and Hermann Köenig. "Derivative and entropy: the only derivations from $C^1(\RR)$ to $C(\RR)$." Electronic Research Announcements in Mathematical Sciences 18 (July 2011): 54–60. http://dx.doi.org/10.3934/era.2011.18.54.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Kopacki, G. "RR Lyrae stars in M4." Communications in Asteroseismology 150 (2007): 383–84. http://dx.doi.org/10.1553/cia150s383.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Szabó, R. "The K2 RR Lyrae Survey." Proceedings of the International Astronomical Union 14, S339 (November 2017): 83–86. http://dx.doi.org/10.1017/s1743921318002272.

Full text

Abstract:

AbstractIn the framework of this project, the K2 RR Lyrae Survey, we proposed to observe thousands of RR Lyrae stars along the Ecliptic in Kepler’s K2 Mission. The high photometric precision and the 80-to-90-day continuous coverage enabled us to investigate in unprecedented detail the light variations of these variable stars which can trace galactic structure. The survey enabled us to conduct a thorough statistical study of RR Lyrae pulsation dynamics, including both old and more recently discovered dynamical phenomena such as resonances, non-radial modes, period doubling and the Blazhko effect. This talk described the K2 RR Lyrae Survey, and discussed the prospects of combining our endeavour with Gaia, LSST and other surveys in the context of studies of Galactic archeology.

APA, Harvard, Vancouver, ISO, and other styles

17

Stellingwerf, R. F., and G. Bono. "Convection in RR Lyrae Stars." International Astronomical Union Colloquium 139 (1993): 252–60. http://dx.doi.org/10.1017/s0252921100117518.

Full text

Abstract:

AbstractConvection undoubtedly plays a strong role in defining the RR Lyrae instability strip, but its effects on amplitude, mode of pulsation, and light curve have always been problematical. One reason is simply that convective models are difficult to compute, and their accuracy is difficult to ascertain. We present results of a new convective survey of RR Lyrae stars that constitute the best models available at this time, with better boundary conditions, physics, zoning, and length of computational run than previous results.

APA, Harvard, Vancouver, ISO, and other styles

18

Bono, G., and R. F. Stellingwerf. "Double-mode RR Lyrae models." International Astronomical Union Colloquium 139 (1993): 275–76. http://dx.doi.org/10.1017/s0252921100117580.

Full text

Abstract:

AbstractDouble-mode RR Lyrae stars (RRd) represent a fundamental testing ground for the theory of stellar pulsation because they play an important role in understanding the interaction between different pulsation modes. In spite of the fact that from an observational point of view the identification of the fundamental (F) and first overtone (IO) periods needs only few periods of light curve coverage (Sandage et al. 1981, Nemec 1985), the theoretical models of double-mode and mixed-mode variables dating back to the original papers of Cox et al. (1983) and Stellingwerf (1975) were not integrated for long enough times to ensure proper mode identification. Recently Kovacs and Buchler (1992) using a standard radiative hydrodynamical code investigated the theoretical properties of RRd stars in more detail. This paper represents a brief description of the results of few cases computed adopting a non-linear, non-local treatment of convective transport, and long integration times to enable positive mode identification.

APA, Harvard, Vancouver, ISO, and other styles

19

Cox, Arthur N. "The Periods of RR Lyrae." International Astronomical Union Colloquium 139 (1993): 409. http://dx.doi.org/10.1017/s0252921100118081.

Full text

Abstract:

AbstractRR Lyrae (0.566 day period) exhibits the Blasko effect that suggests another natural mode with almost the same period as the accepted fundamental radial mode. This mode might be nonradial, but no one has done an extensive evaluation of this idea. An investigation requires a model that includes the deep composition structure where g-modes of low angular (observable) degree have weight and amplitude. An RR Lyrae model including the outer half of the mass and more than 99% of the radius, based on an asymptotic giant branch model from Hollowell (private communication), see below, was used for this study. It includes composition gradient ramps between the primordial surface hydrogen and helium and the almost pure helium shell and the one between this helium shell and the convective core that is burning helium.Nonradial mode periods almost resonant with the radial fundamental mode period seem to occur for all low ℓ values. In addition to significant pulsation amplitudes in the composition gradient regions where the Brunt Väisälä frequency is large, these low degree and low radial order modes have near-surface amplitudes very similar to the low order radial modes. These modes are evanescent in the convective core. Classical K and γ effects give enough driving in the very low mass surface layers, so that important deep radiative damping for these modes does not completely stabilize nonradial g-mode pulsations. The g4, ℓ=1 mode gives a. double-mode RR Lyrae with Blasko effect.A nonradial mode may not always be visible, depending on how rotation presents the nonspherical pulsations to the observer. Thus the Blasko effect might come and go, as observed for maybe 20% of all RR Lyrae variables. For many, the Blasko effect may not be observable, even when a nonradial mode is there.

APA, Harvard, Vancouver, ISO, and other styles

20

Baselli, G., A. Porta, S. Cerutti, E. G. Caiani, D. Lucini, and M. Pagani. "RR–arterial pressure variability relationships." Autonomic Neuroscience 90, no. 1-2 (July 2001): 57–65. http://dx.doi.org/10.1016/s1566-0702(01)00268-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Liu, Tianxing. "Synthetic RR Lyrae velocity curves." Publications of the Astronomical Society of the Pacific 103 (February 1991): 205. http://dx.doi.org/10.1086/132809.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Kollath, Zoltan, J. Robert Buchler, and Michael Feuchtinger. "RR Lyrae: Theory versus Observation." Astrophysical Journal 540, no. 1 (September 2000): 468–73. http://dx.doi.org/10.1086/309330.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Alekseev, A., A. Mironov, and A. Morozov. "B-independence of RR charges." Physics Letters B 532, no. 3-4 (April 2002): 350–56. http://dx.doi.org/10.1016/s0370-2693(02)01569-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Davis, Cecil G. "Colors of RR Lyrae Stars." Publications of the Astronomical Society of the Pacific 111, no. 756 (February 1999): 196–202. http://dx.doi.org/10.1086/316308.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Moss, Arthur J. "Heart Rate (RR Interval) Variability." Annals of Noninvasive Electrocardiology 1, no. 4 (October 1996): 347–48. http://dx.doi.org/10.1111/j.1542-474x.1996.tb00288.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Staña, Jirí. "The Rally Rejviz (RR) Project." Prehospital and Disaster Medicine 15, S2 (September 2000): S69. http://dx.doi.org/10.1017/s1049023x00031708.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Szabó, Róbert, Katrien Kolenberg, László Molnár, Emese Plachy, Péter Klagyivik, and Ottó Hanyecz. "The K2 RR Lyrae Survey." EPJ Web of Conferences 160 (2017): 04004. http://dx.doi.org/10.1051/epjconf/201716004004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Kuehn, Charles A., Pawel Moskalik, and Jason A. Drury. "RR Lyrae Stars in M4." EPJ Web of Conferences 160 (2017): 04011. http://dx.doi.org/10.1051/epjconf/201716004011.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Reid, N. "The M5 RR Lyrae population." Monthly Notices of the Royal Astronomical Society 278, no. 2 (January 11, 1996): 367–94. http://dx.doi.org/10.1093/mnras/278.2.367.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Molnár, L., Z. Kolláth, R. Szabó, S. Bryson, K. Kolenberg, F. Mullally, and S. E. Thompson. "NONLINEAR ASTEROSEISMOLOGY OF RR LYRAE." Astrophysical Journal 757, no. 1 (September 4, 2012): L13. http://dx.doi.org/10.1088/2041-8205/757/1/l13.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Didi, Yin, Gao Naiyun, Zhang Kejia, Li Lei, and Deng Yang. "Microcystin-RR degradation by ozonation." Desalination and Water Treatment 55, no. 4 (May 20, 2014): 1060–67. http://dx.doi.org/10.1080/19443994.2014.920729.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Akhmedov, Emil T., Anton A. Gerasimov, and Samson L. Shatashvili. "On unification of RR couplings." Journal of High Energy Physics 2001, no. 07 (July 26, 2001): 040. http://dx.doi.org/10.1088/1126-6708/2001/07/040.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Abdullaev, N. T., O. A. Dyshin, and A. S. Abbasquliev. "Assessment of RR-Intervalogram Instability." Biomedical Engineering 45, no. 3 (August 23, 2011): 104–6. http://dx.doi.org/10.1007/s10527-011-9220-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Gámez, José L., Gustavo A. Muñoz-Fernández, and Juan B. Seoane-Sepúlveda. "Lineability and additivity in RR." Journal of Mathematical Analysis and Applications 369, no. 1 (September 2010): 265–72. http://dx.doi.org/10.1016/j.jmaa.2010.03.036.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Evstifeev, M. I., D. P. Eliseev, and I. B. Chelpanov. "MEMS RR-type gyro with a moving electrode." Giroskopiya i Navigatsiya 23, no. 4 (2015): 67–76. http://dx.doi.org/10.17285/0869-7035.2015.23.4.067-076.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Scully, B. T., R. L. Beiriger, Teresa Olczyk, and J. R. Stavely. "`BeltGlade RR-1', `BeltGlade RR-2', and `BeltGlade RR-3': Rust-resistant Snap Bean Breeding Lines with the Ur-4 and Ur-11 Genes." HortScience 35, no. 6 (October 2000): 1180–82. http://dx.doi.org/10.21273/hortsci.35.6.1180.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Kunder, Andrea, Angeles Pérez-Villegas, R. Michael Rich, Jonathan Ogata, Emma Murari, Emilie Boren, Christian I. Johnson, et al. "The Bulge Radial Velocity Assay for RR Lyrae Stars (BRAVA-RR) DR2: A Bimodal Bulge?" Astronomical Journal 159, no. 6 (May 21, 2020): 270. http://dx.doi.org/10.3847/1538-3881/ab8d35.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Vannini, Laura, and Judith H. Willis. "Localization of RR-1 and RR-2 cuticular proteins within the cuticle of Anopheles gambiae." Arthropod Structure & Development 46, no. 1 (January 2017): 13–29. http://dx.doi.org/10.1016/j.asd.2016.10.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Kubwabo, Cariton, Natalia Vais, and Frank M. Benoit. "Identification of Microcystin-RR and [Dha7]Microcystin-RR in Commercial Standards by Electrospray Ionization Mass Spectrometry." Journal of AOAC INTERNATIONAL 87, no. 4 (July 1, 2004): 1028–31. http://dx.doi.org/10.1093/jaoac/87.4.1028.

Full text

Abstract:

Abstract Three different commercial standards of microcystin-RR were assessed for purity by the liquid chromatography coupled with electrospray ionization mass spectrometry (LC/ESI/MS) technique. Although the liquid chromatograms with photodiode array detector for each standard looked virtually identical, the analysis of corresponding mass spectra revealed that only one of them contained microcystin-RR per purity assay. The second standard was a mixture of microcystin-RR, and its demethyl variant identified as [Dha7]microcystin-RR, and the third one contained [Dha7]microcystin-RR only. We strongly recommend applying LC coupled with MS for purity assay of microcystin standards.

APA, Harvard, Vancouver, ISO, and other styles

40

Tsujimoto, T., M. Miyamoto, and Y. Yoshii. "The Absolute Magnitude Of RR Lyrae Stars." Highlights of Astronomy 11, no. 1 (1998): 580. http://dx.doi.org/10.1017/s1539299600022383.

Full text

Abstract:

The present determination of the absolute magnitude .Mv(RR) of RR Lyrae stars is twofold, relying upon Hipparcos proper motions and trigonometric parallaxes separately. First, applying the statistical parallax method to the proper motions, we find < Mv(RR)>= 0.69 ± 0.10 for 99 halo RR Lyraes with <[Fe/H]> = -1.58. Second, applying the Lutz-Kelker correction to the RR Lyrae HIP95497 with the most accurately measured parallax, we obtain Mv(RR) = 0.57-0.74 at [Fe/H]=-1.6. Furthermore, allowing full use of low accuracy and negative parallaxes as well for 125 RR Lyraes with - 2.49≤[Fe/H]≤0.07, the maximum likelihood estimation yields the relation, Mv(RR)= (0.59±0.37)+(0.20±0.63)([Fe/H]+1.60), which formally agrees with the recent preferred relation. The same estimation yields again My (RR) = 0.65 ± 0.33 for the 99 halo RR Lyraes. Although the formal errors in the latter two estimates are rather large, all of the four results suggest the fainter absolute magnitude, My(RR)=0.6-0.7 at [Fe/H]=-1.6. The present results still provide the lower limit on the age of the universe which is inconsistent with a fiat, matter-dominated universe and current estimates of the Hubble constant.

APA, Harvard, Vancouver, ISO, and other styles

41

Watanabe, Daisuke, Satoshi Morimoto, Noriko Morishima, Yoichiro Kato, Yoji Nagashima, Noriyuki Shibata, Atsuhiro Ichihara, and Ludwik K. Malendowicz. "Adrenal (Pro)renin Receptor Expression and Serum Soluble (Pro)renin Receptor Concentration in Primary Aldosteronism." International Journal of Endocrinology 2020 (September 27, 2020): 1–9. http://dx.doi.org/10.1155/2020/9640103.

Full text

Abstract:

The (pro)renin receptor [(P)RR] is a multifunctioning protein playing roles in various pathological conditions. A soluble form of (P)RR [s(P)RR] has been considered a biomarker for (P)RR expression in tissues. Expression of (P)RR has been described in aldosterone-producing adenoma (APA), but the roles of (P)RR have yet to be fully determined. This study investigated the significance of (P)RR and serum s(P)RR concentrations in patients with APA. We evaluated associations between (P)RR expression and expression of CYP11B2, an aldosterone synthase, and aldosterone production by the adrenal glands and assessed the relationships between serum s(P)RR concentration and background factors. (P)RR colocalized with CYP11B2 and expression levels of (P)RR were positively associated with those of CYP11B2 in APA tissues. (P)RR immunoreactivity in these tissues correlated positively with plasma aldosterone concentrations (PAC) and urinary aldosterone excretion. Also, in APA, (P)RR mRNA abundance was positively correlated with β-catenin mRNA abundance. Significant positive correlations were identified between serum s(P)RR concentration and plasma glucose, hemoglobin A1c, and serum creatinine levels, but not with PAC (in either peripheral vein or adrenal vein) or adrenal (P)RR expression level. This study showed that (P)RR expression level correlates with CYP11B2 expression in APA tissues and PAC and urinary aldosterone excretion, suggesting that (P)RR expression may contribute to aldosterone synthesis via CYP11B2 activation in APAs, although serum s(P)RR concentration failed to show any significant relationship with adrenal (P)RR expression. Adrenal (P)RR activity might offer a therapeutic target in the treatment of PA, although this issue needs to be investigated in future studies.

APA, Harvard, Vancouver, ISO, and other styles

42

Yonglu, ZHANG, HUANG Xianing, XIAO Wenqing, ZHONG Qing, and GU Kangding. "Purification and identification of microcystin-RR." Chinese Journal of Chromatography 31, no. 3 (2013): 260–63. http://dx.doi.org/10.3724/sp.j.1123.2012.11005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Chapple, Christopher. "Reply to Jonas U, Rackley RR." European Urology 49, no. 1 (January 2006): 188–90. http://dx.doi.org/10.1016/j.eururo.2005.09.014.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Walker, Alistair R. "RR Lyraes in the Magellanic Clouds." International Astronomical Union Colloquium 139 (1993): 15–20. http://dx.doi.org/10.1017/s0252921100116860.

Full text

Abstract:

AbstractRecent work on the Magellanic Cloud RR Lyrae stars is reviewed. The absolute magnitudes of LMC RR Lyraes, when calibrated from a distance modulus of 18.5 mag, disagrees with the Galactic calibration. The revised distance scale makes distances greater, and ages younger, within our galaxy. Field star studies show that the “halo” population of the LMC is very similar to that of our own Galaxy outside of the solar circle. This result supports a Searle and Zinn model of galaxy formation.

APA, Harvard, Vancouver, ISO, and other styles

45

Bono, G., and R. F. Stellingwerf. "A survey of RR Lyrae models." International Astronomical Union Colloquium 139 (1993): 262. http://dx.doi.org/10.1017/s0252921100117531.

Full text

Abstract:

AbstractAn extensive grid of non-linear pulsating models of RR Lyrae stars have been computed. To simulate the outer regions of these variables a non-local and time-dependent treatment of convective transport has been adopted. In this poster we briefly describe some new features of the instability strip (IS).

APA, Harvard, Vancouver, ISO, and other styles

46

Kovács, G. "Modelling Cepheids and RR Lyrae Stars." International Astronomical Union Colloquium 139 (1993): 267–74. http://dx.doi.org/10.1017/s0252921100117579.

Full text

Abstract:

AbstractWe review the recent nonlinear hydrodynamical results and the numerical problems to be solved by the next generation of codes. The behavior of the Fourier parameters and double-mode RR Lyrae pulsation will be discussed in detail. We emphasize the importance of the implementation of the various adaptive-mesh schemes for stellar pulsations. A further goal is the substitution of the artificial viscosity with modern shock capturing methods and a better treatment of radiative transfer. Convection however, must ultimately be included in order to supply the necessary physical mechanism for dissipation.

APA, Harvard, Vancouver, ISO, and other styles

47

Lee, Young-Wook. "Evolutionary Models of RR Lyrae Stars." International Astronomical Union Colloquium 139 (1993): 294–303. http://dx.doi.org/10.1017/s025292110011766x.

Full text

Abstract:

As tracers of old stellar populations and as primary Population II standard candles, RR Lyrae stars have played an important role in the development of modern astronomy. Our knowledge of stellar evolution has identified these variable stars in a core helium burning phase of low-mass star evolution, the hoiizontal-branch (HB) phase. Consequently, not only to understand fully the nature of RR Lyrae stars, but also to apply them correctly as population probes and distance indicators, we must understand the underlying evolutionary effect of HB stars.In this paper, I briefly review the most important properties of RR Lyrae stars predicted from the HB evolutionary models, and present many pieces of supporting evidence for these models. For the implications of these models on the chronology of the Galactic formation and on the cosmological distance scale, the reader is referred to several recent publications by Lee (1992a,b,c,d).

APA, Harvard, Vancouver, ISO, and other styles

48

Dorman, Ben. "Stellar Structure and RR Lyrae Masses." International Astronomical Union Colloquium 139 (1993): 309–11. http://dx.doi.org/10.1017/s0252921100117701.

Full text

Abstract:

AbstractI describe qualitatively the constraints on RR Lyrae masses that arise from consideration of the interior structure of Horizontal Branch (HB) stars. Briefly, the stellar models lying within the temperature range of the instability strip are slightly less massive than those with deep exterior convection zones. I discuss therefore what brings about the existence of these zones in the models.

APA, Harvard, Vancouver, ISO, and other styles

49

Fernley, J. "Period Shifts in RR Lyrae Stars." International Astronomical Union Colloquium 139 (1993): 332–34. http://dx.doi.org/10.1017/s0252921100117750.

Full text

Abstract:

Using recently published infrared photometry of RR Lyrae stars from both the field (Fernley et al. 1992) and globular clusters (Longmore et al. 1990), period shifts have been calculated using the mean (V – K) colour rather than the mean (B – V) colour employed in most previous analyses (e.g., Sandage 1990 and references therein). The advantage of using (V – K) rather than (B – V) is the reduced sensitivity to, firstly, metallicity and, secondly, non-LTE radiation. This latter occurs in many RR Lyrae stars near maximum light and clearly should not be included when calculating the mean colour and hence, mean temperature. This, and all other aspects of the present paper, are discussed more fully in Fernley (1992a).The mean (V – K) colour of both the field and cluster stars were de-reddened using the maps of Burstein and Heiles (1982) and converted to effective temperature using the calibration of Fernley (1989).

APA, Harvard, Vancouver, ISO, and other styles

50

Teays, Terry J. "The Blazhko Effect in RR Lyrae." International Astronomical Union Colloquium 139 (1993): 410–18. http://dx.doi.org/10.1017/s0252921100118093.

Full text

Abstract:

AbstractThe cause of the Blazhko effect, the long-term modulation of the light and radial velocity curves of some RR Lyr stars, is still not understood. The observational characteristics of the Blazhko effect are discussed in §1. Some preliminary results are presented from aomw recent of campaigns to observe RR Lyr, using the International Ultraviolet Explorer along with ground-based spectroscopy and photometry, throughout a pulsation cycle, at a variety of Blazhko phases. A set of ultraviolet light curves have been generated from low dispersion IUE spectra. In addition, the (visual) light curves from IUE's Fine Error Sensor are analyzed using the Fourier decomposition technique. The values of the parameters ϕ21 and R21 at different Blazhko phasas of RR Lyr span the range of values found for non-Blazhko variables of similar period.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'RR'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles