Analysis of Long-Term Variability of Cataclysmic Variables

Photometric variability in cataclysmic variables (CVs) on time scales longer than a few days can be most effectively addressed by automated long-term monitoring programs such as that of RoboScope (Honeycutt & Turner 1992): more than 100 CVs have been monitored for about 13 years, obtaining 75 to 150 measurements per year for each system. Among the techniques being explored for analysing this data set is the use of the structure function (SF), an autocorrelation tool employed extensively for the study of the light curves of AGNs (e.g. Hufnagel & Bregman 1992). A first order SF measures the scatter in a time series of magnitudes, m, as as a function of the time lag, τ (Hughes, Aller & Aller 1992).

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Long-Term Variability and Outburst Activity of FS Aurigae: Further Evidence for a Third Body in the System

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311026986 ◽

2011 ◽

Vol 7 (S282) ◽

pp. 79-80

Author(s):

V. Neustroev ◽

G. Sjoberg ◽

G. Tovmassian ◽

S. Zharikov ◽

T. Arranz Heras ◽

...

Keyword(s):

Transfer Rate ◽

Mass Transfer Rate ◽

Cataclysmic Variables ◽

Close Binary ◽

Third Body ◽

Secondary Star ◽

Long Term Monitoring ◽

Binary Orbit ◽

Term Monitoring

AbstractFS Aurigae is famous for a variety of uncommon and puzzling periodic photometric and spectroscopic variabilities which do not fit well into any of the established sub-classes of cataclysmic variables. Here we present preliminary results of long-term monitoring of the system, conducted during the 2010-2011 observational season. We show that the long-term variability of FS Aur and the character of its outburst activity may be caused by variations in the mass transfer rate from the secondary star as the result of eccentricity modulation of a close binary orbit induced by the presence of a third body on a circumbinary orbit.

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Long-term monitoring programme of the hydrological variability in the Mediterranean Sea: a first overview of the HYDROCHANGES network

Ocean Science ◽

10.5194/os-9-301-2013 ◽

2013 ◽

Vol 9 (2) ◽

pp. 301-324 ◽

Cited By ~ 37

Author(s):

K. Schroeder ◽

C. Millot ◽

L. Bengara ◽

S. Ben Ismail ◽

M. Bensi ◽

...

Keyword(s):

Time Series ◽

Mediterranean Sea ◽

Sampling Interval ◽

Global Changes ◽

Hydrological Variability ◽

Long Term Monitoring ◽

The Mediterranean ◽

Set Up ◽

Term Monitoring

Abstract. The long-term monitoring of basic hydrological parameters (temperature and salinity), collected as time series with adequate temporal resolution (i.e. with a sampling interval allowing the resolution of all important timescales) in key places of the Mediterranean Sea (straits and channels, zones of dense water formation, deep parts of the basins), constitute a priority in the context of global changes. This led CIESM (The Mediterranean Science Commission) to support, since 2002, the HYDROCHANGES programme (http//www.ciesm.org/marine/programs/hydrochanges.htm), a network of autonomous conductivity, temperature, and depth (CTD) sensors, deployed on mainly short and easily manageable subsurface moorings, within the core of a certain water mass. The HYDROCHANGES strategy is twofold and develops on different scales. To get information about long-term changes of hydrological characteristics, long time series are needed. But before these series are long enough they allow the detection of links between them at shorter timescales that may provide extremely valuable information about the functioning of the Mediterranean Sea. The aim of this paper is to present the history of the programme and the current set-up of the network (monitored sites, involved groups) as well as to provide for the first time an overview of all the time series collected under the HYDROCHANGES umbrella, discussing the results obtained thanks to the programme.

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