[ITAL]BVI[/ITAL] Time-Series Data of the Galactic Globular Cluster NGC 3201. I. RR Lyrae Stars

2002 ◽  
Vol 124 (3) ◽  
pp. 1528-1554 ◽  
Author(s):  
A. M. Piersimoni ◽  
G. Bono ◽  
V. Ripepi
2013 ◽  
Vol 9 (S301) ◽  
pp. 241-248
Author(s):  
Róbert Szabó

AbstractThe Blazhko effect is the conspicuous amplitude and phase modulation of the pulsation of RR Lyrae stars that was discovered in the early 20th century. The field of study of this mysterious modulation has recently been invigorated thanks to the space photometric missions providing long, uninterrupted, ultra-precise time-series data. In this paper I give a brief overview of the new observational findings related to the Blazhko effect, such as extreme modulations, irregular modulation cycles and additional periodicities. I argue that these findings together with dedicated ground-based efforts provide us now with a fairly complete picture and a good starting point to theoretical investigations. Indeed, new, unpredicted dynamical phenomena have been discovered in Blazhko RR Lyrae stars, such as period doubling, high-order resonances, three-mode pulsation and low-dimensional chaos. These led to the proposal of a new explanation to this century-old enigma, namely a high-order resonance between radial modes. Along these lines I present the latest efforts and advances from the theoretical point of view. Lastly, amplitude variations in Cepheids are discussed.


2019 ◽  
Vol 14 (S351) ◽  
pp. 478-481
Author(s):  
M. I. Moretti ◽  
I. Musella ◽  
M. Marconi ◽  
V. Ripepi ◽  
R. Molinaro

AbstractIn the context of the STRucture and Evolution of the GAlaxy survey, we describe the preliminary results obtained for the fields around the globular cluster Pal 3 (about 2.75 square degrees), by exploiting the obtained g, r, i time series photometry. The final aim is to use variable stars as tools to verify and study the presence of streams around Pal 3. We found 20 candidate variable stars of which 7 RR Lyrae stars possibly belonging to Pal 3, also at large distance from the center. The distribution of the candidate RR Lyrae seems to confirm a preferential distribution in the north-east direction, confirming previous results in literature.


2002 ◽  
Vol 185 ◽  
pp. 140-141
Author(s):  
Y.-B. Jeon ◽  
S.-L. Kim ◽  
H. Lee ◽  
M.G. Lee

AbstractThrough time-series CCD photometry of the globular cluster M 53, we have discovered eight new SX Phoenicis type stars. All the new SX Phoenicis stars are located in the blue straggler star region in the color-magnitude diagram of M 53. In addition, we have obtained light curves for 45 known RR Lyrae stars.


1995 ◽  
Vol 155 ◽  
pp. 387-388
Author(s):  
Katalin Barlai ◽  
B. Szeidl

AbstractPeriod behaviour of 62 RR Lyrae stars in the M15 globular cluster has been investigated. About one half of the sample (30 stars) exhibited linear period change. The remaining 32 variables can be characterized by abrupt or erratic changes in their periods.


1995 ◽  
Vol 110 ◽  
pp. 1712 ◽  
Author(s):  
Patricia Purdue ◽  
N. A. Silbermann ◽  
Pamela Gay ◽  
Horace A. Smith

1985 ◽  
Vol 57 ◽  
pp. 287 ◽  
Author(s):  
J. M. Nemec ◽  
J. E. Hesser ◽  
P. P. Ugarte

2019 ◽  
Vol 490 (2) ◽  
pp. 1498-1508
Author(s):  
Nicolas Longeard ◽  
Nicolas Martin ◽  
Rodrigo A Ibata ◽  
Michelle L M Collins ◽  
Benjamin P M Laevens ◽  
...  

ABSTRACT We present a photometric and spectroscopic study of the Milky Way satellite Laevens 3. Using MegaCam/Canada–France–Hawaii Telescope $g$ and $i$ photometry and Keck II/DEIMOS multi-object spectroscopy, we refine the structural and stellar properties of the system. The Laevens 3 colour–magnitude diagram shows that it is quite metal-poor, old ($13.0 \pm 1.0$ Gyr), and at a distance of $61.4 \pm 1.0$ kpc, partly based on two RR Lyrae stars. The system is faint ($M_V = -2.8^{+0.2}_{-0.3}$ mag) and compact ($r_h = 11.4 \pm 1.0$ pc). From the spectroscopy, we constrain the systemic metallicity (${\rm [Fe/H]}_\mathrm{spectro} = -1.8 \pm 0.1$ dex) but the metallicity and velocity dispersions are both unresolved. Using Gaia DR2, we infer a mean proper motion of $(\mu _\alpha ^*,\mu _\delta)=(0.51 \pm 0.28,-0.83 \pm 0.27)$ mas yr−1, which, combined with the system’s radial velocity ($\langle v_r\rangle = -70.2 \pm 0.5 {\rm \, km \,\, s^{-1}}$), translates into a halo orbit with a pericenter and apocenter of $40.7 ^{+5.6}_{-14.7}$ and $85.6^{+17.2}_{-5.9}$ kpc, respectively. Overall, Laevens 3 shares the typical properties of the Milky Way’s outer halo globular clusters. Furthermore, we find that this system shows signs of mass segregation that strengthens our conclusion that Laevens 3 is a globular cluster.


2015 ◽  
Vol 219 (2) ◽  
pp. 25 ◽  
Author(s):  
J. Jurcsik ◽  
P. Smitola ◽  
G. Hajdu ◽  
Á. Sódor ◽  
J. Nuspl ◽  
...  

2015 ◽  
Vol 808 (1) ◽  
pp. 11 ◽  
Author(s):  
J. R. Neeley ◽  
M. Marengo ◽  
G. Bono ◽  
V. F. Braga ◽  
M. Dall’Ora ◽  
...  

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