scholarly journals Big planets could alter star rotation

Nature ◽  
2014 ◽  
Vol 509 (7500) ◽  
pp. 263-263
Keyword(s):  
Star Rotation

scholarly journals Twenty Years of Dedicated Photometry of RS CVn at Catania Observatory

1983 ◽  
Vol 71 ◽  
pp. 387-390
Author(s):  
C. Blanco ◽  
S. Catalano ◽  
E. Marilli ◽  
M. Rodonò
Keyword(s):  
Light Curves ◽  
Angular Rotation ◽  
Similar Activity ◽  
Activity Phase ◽  
Spotted Stars ◽  
Spotted Star ◽  
Complete Set ◽  
Star Rotation

We present a complete set of yearly seasonal light curves (LC) of RS CVn obtained from 1963 to 1982 at Catania Observatory, integrated with two LCs obtained by Ludington (1978) in 1975 and 1976. This unique observation set vividly shows (Figure l) the migrating outside of eclipse “photometric wave” (PW), which was first evidenced by Catalano and Rodonò (1967) and it is now considered the distinctive photometric feature of RS CVn binaries as well as of other spotted stars. By attributing the PW to surface inhomogeneities, or spots, whose visibility is modulated by the spotted star rotation, the present PW migration toward decreasing orbital phases indicates that the angular rotation of the KOIV spotted component is slightly lower than the orbital one. An inspection of Figure 1 readly shows that the almost sinusoidal PW has been fairly stable from 1963 up to 1981, when a double-peaked wave, still present in the 1982 LC, developed. Most probably the “unusual” 1949 LC by Keller and Limber (1951) and the 1976 one by Ludington (1978) were obtained at a similar activity phase.

scholarly journals Fiber Fed Spectrograph for Line Variability Studies

1988 ◽  
Vol 132 ◽  
pp. 31-34 ◽  
Author(s):  
P. Felenbok ◽  
J. Guérin
Keyword(s):  
Line Profile ◽  
Main Sequence ◽  
Single Site ◽  
Be Stars ◽  
Correlated Observations ◽  
Rotational Modulation ◽  
High Flexibility ◽  
Gain Access ◽  
Star Rotation

In our studies of activity in pre-main sequence Herbig Ae/Be stars we are mainly interested in searching rotational modulation of line profile. If the period of star rotation is of the order of one or two days, the data collected from a single site is insufficient. This led us to start correlated observations from two or three sites spread as much as possible in longitude. Our first bi-site observations started in 1982 on AB Aur from two observatories located 11 hours apart.: CFHT in Hawaï and OHP in France. To achieve a high flexibility and to gain access to telescopes without attached spectrographs. We built an instrument that is mobile and specially designed for line profile studies.

scholarly journals The Effect of Neutron Star Rotation on the Properties of Thermonuclear X‐Ray Bursts

2004 ◽  
Vol 608 (2) ◽  
pp. 930-934 ◽  
Author(s):  
Michael P. Muno ◽  
Duncan K. Galloway ◽  
Deepto Chakrabarty
Keyword(s):  
Neutron Star ◽  
X Ray ◽  
Star Rotation

scholarly journals The rotation period distribution of the rich Pleiades-age southern open cluster NGC 2516

2020 ◽  
Vol 641 ◽  
pp. A51 ◽  
Author(s):  
D. J. Fritzewski ◽  
S. A. Barnes ◽  
D. J. James ◽  
K. G. Strassmeier
Keyword(s):  
Time Series ◽  
Open Cluster ◽  
Rotation Period ◽  
Open Clusters ◽  
Ccd Photometry ◽  
Activity Diagram ◽  
Cool Star ◽  
Period Distribution ◽  
Rotational Distribution ◽  
Star Rotation

Aims. We wish to measure the cool star rotation period distribution for the Pleiades-age rich open cluster NGC 2516 and use it to determine whether cluster-to-cluster variations exist in otherwise identical open clusters. Methods. We obtained 42 d-long time-series CCD photometry of NGC 2516 in the V and Ic filters using the Yale 1 m telescope at CTIO and performed a number of related analyses, including PSF-based time-series photometry. Our data are complemented with additional information from several photometric datasets, literature radial velocities, and Gaia DR2 astrometry. All available data are used to construct an integrated membership list for NGC 2516, containing 844 stars in our ≈1° field of view. Results. We derived 308 rotation periods for late-F to mid-M cluster members from our photometry. We identified an additional 247 periodic M dwarf stars from a prior study as cluster members, and used these to construct a 555-star rotation period distribution for NGC 2516. The colour-period diagram (in multiple colours) has almost no outliers and exhibits the anticipated triangular shape, with a diagonal slow rotator sequence that is preferentially occupied by the warmer stars along with a flat fast rotator sequence that is preferentially populated by the cooler cluster members. We also find a group of extremely slowly rotating M dwarfs (10 d ≲ Prot ≲ 23 d), forming a branch in the colour-period diagram which we call the “extended slow rotator sequence”. This, and other features of the rotational distribution can also be found in the Pleiades, making the colour-period diagrams of the two clusters nearly indistinguishable. A comparison with the well-studied (and similarly aged) open cluster M 35 indicates that the cluster’s rotational distribution is also similarly indistinguishable from that of NGC 2516. Those for the open clusters M 50 and Blanco 1 are similar, but data issues for those clusters make the comparisons somewhat more ambiguous. Nevertheless, we demonstrate the existence of a representative zero-age main sequence rotational distribution and provide a simple colour-independent way to represent it. We perform a detailed comparison of the NGC 2516 rotation period data with a number of recent rotational evolution models. Using X-ray data from the literature, we also construct the first rotation-activity diagram for solar-type stars in NGC 2516, one that we find is essentially indistinguishable from those for the Pleiades and Blanco 1. Conclusions. The two clusters NGC 2516 and Pleiades can be considered twins in terms of stellar rotation and related properties (and M 35, M 50, and Blanco 1 are similar), suggesting that otherwise identical open clusters also have intrinsically similar cool star rotation and activity distributions.

On the Uv Cet-Type Star Rotation

1970 ◽  
pp. 249-253 ◽  
Author(s):  
R. E. Gershberg
Keyword(s):  
Type Star ◽  
Star Rotation

Sun as a star: Rotation rates from the Ca K-index

Solar Physics ◽  
1987 ◽  
Vol 109 (2) ◽  
pp. 387-391 ◽  
Author(s):  
Jagdev Singh ◽  
W. C. Livingston
Keyword(s):  
Rotation Rates ◽  
K Index ◽  
Star Rotation

scholarly journals Boson star rotation: A Newtonian approximation

1995 ◽  
Vol 52 (10) ◽  
pp. 5724-5728 ◽  
Author(s):  
Vanda Silveira ◽  
Claudio M. G. de Sousa
Keyword(s):  
Newtonian Approximation ◽  
Star Rotation
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