scholarly journals Light curve analysis of the late type binary V523 Cassiopeiae

2009 ◽  
pp. 45-48 ◽  
Author(s):  
O. Latkovic ◽  
M. Zboril ◽  
G. Djurasevic
Keyword(s):  
Light Curve ◽  
Monitoring Program ◽  
Neck Region ◽  
Bright Spot ◽  
Late Type ◽  
Light Curve Analysis ◽  
Type Contact ◽  
Contact Binary ◽  
Previous Solution

We present the analysis of V and R light curves of the late type contact binary V523 Cas for the season of 2006. These observations make part of the monitoring program aimed at studying the long-term light curve variability in this system. Our results confirm that the system is in an over contact configuration, and include a bright spot in the neck region of the cooler and larger primary. We compare these results with the previous solution, obtained for the season 2005 dataset and discuss the differences.

scholarly journals Structure of the Gaseous Disk in RX Cas

1980 ◽  
Vol 88 ◽  
pp. 269-270
Author(s):  
S. Kříž
Keyword(s):  
Light Curve ◽  
Light Curves ◽  
Bright Spot ◽  
Period Increase ◽  
Long Period ◽  
Short Period ◽  
Observational Errors ◽  
The Times ◽  
Image Position

RX Cas appers to be a long-period Algol-like binary with very fast mass exchange (Struve 1944). In the period 1975-1977, this star was observed photometrically by Arsenijevič, Grygar, Harmanec, Horn, Koubský, Kříž and Pavlovski at Hvar Observatory (Yugoslavia) and by Zverko at Skalnaté Pleso Observatory (Czechoslovakia). The resulting UBV light curves seem to be rather peculiar, for the following reasons:1) Combining our observations with the older ones, we obtain the following formula for the times of minima: The period increase is surprisingly high.2) The scatter of observed points is considerable (about 0.2 mag.) and cannot be caused by observational errors. It corresponds to short period light variations on the time scale of several days.3) After J.D. 24422660, the brightness of the whole system decreased in all colours. This decrease is about 0.2 mag. in V colour and 0.5 mag. in U colour. Only after J.D. 2442900 the brightness increased again. Such a behaviour confirms the reality of old observations by Gaposchkin (1944) and Martynov (1950) who found a long-term light variation with a period of approximately 500 days.4) The part of the light curve around the phase 0.75 is definitely much lower than the corresponding part around the phase 0.25. This effect is most pronounced in the ultraviolet; the depression around the phase 0.75 is much deeper than the secondary minimum. This behaviour is opposite to the behaviour of dwarf novae. Instead of a bright shoulder connected with a bright spot, we observe some darkening.

scholarly journals A 20-year H2O maser monitoring program with the Medicina 32-m telescope

2007 ◽  
Vol 3 (S242) ◽  
pp. 223-227 ◽  
Author(s):  
J. Brand ◽  
M. Felli ◽  
R. Cesaroni ◽  
C. Codella ◽  
G. Comoretto ◽  
...  
Keyword(s):  
Sampling Rate ◽  
Monitoring Program ◽  
Late Type ◽  
Maser Emission ◽  
Star Forming ◽  
Star Forming Regions ◽  
Vlbi Observations ◽  
Water Maser ◽  
Representative Samples

AbstractThe Arcetri/Bologna H2O maser group has been monitoring the 1.3-cm water maser emission from a sample of 43 star-forming regions (SFRs) and 22 late-type stars for about 20 years at a sampling rate of 4-5 observations each year, using the 32-m Medicina Radio Telescope (HPBW 1.′9 at 22 GHz). For the late-type stars we observe representative samples of OH/IR-stars, Mira's, semi-regular variables, and supergiants. The SFR-sample spans a large interval in FIR luminosity of the associated Young Stellar Object (YSO), from 20 L⊙ to 1.5 × 106 L⊙, and offers a unique data base for the study of the long-term (years) variability of the maser emission in regions of star formation.This presentation concerns only the masers in SFRs. The information obtained from single-dish monitoring is complementary to what is extracted from higher-resolution (VLA and VLBI) observations, and can better explore the velocity domain and the long-term variability therein.We characterize the variability of the sources in various ways and we study how it depends on the luminosity and other properties of the associated YSO and its environment.

First Ground-Based Photometry and Light Curve Analysis of the Recently Discovered Contact Binary HX UMa

2005 ◽  
pp. 305-308
Author(s):  
S. Selam ◽  
B. Albayrak ◽  
M. Yilmaz ◽  
H.V. Şenavci ◽  
İ Özavci ◽  
...  
Keyword(s):  
Light Curve ◽  
Curve Analysis ◽  
Light Curve Analysis ◽  
Contact Binary

scholarly journals A CCD photometric study of the late type contact binary EK Comae Berenices

New Astronomy ◽  
2010 ◽  
Vol 15 (8) ◽  
pp. 662-668 ◽  
Author(s):  
Sukanta Deb ◽  
Harinder P. Singh ◽  
T.R. Seshadri ◽  
Ranjan Gupta
Keyword(s):  
Photometric Study ◽  
Late Type ◽  
Type Contact ◽  
Contact Binary

Light Curve of CR Bootis 1990–2012 from the Indiana Long-Term Monitoring Program

2013 ◽  
Vol 125 (924) ◽  
pp. 126-142 ◽  
Author(s):  
R. Kent Honeycutt ◽  
Brice R. Adams ◽  
George W. Turner ◽  
Jeff W. Robertson ◽  
Eric M. Ost ◽  
...  
Keyword(s):  
Light Curve ◽  
Monitoring Program ◽  
Long Term Monitoring ◽  
Term Monitoring

scholarly journals Light Curve Analysis and System Parameters of Contact Binary V608 Cassiopeiae

2018 ◽  
Vol 1144 ◽  
pp. 012166
Author(s):  
P Panpiboon ◽  
R Boontua ◽  
W Thongcha ◽  
W Choawanklang
Keyword(s):  
Light Curve ◽  
Curve Analysis ◽  
Light Curve Analysis ◽  
System Parameters ◽  
Contact Binary

scholarly journals Observation and Analysis of RW Doradus

2007 ◽  
Vol 24 (4) ◽  
pp. 199-207 ◽  
Author(s):  
B. F. Marino ◽  
W. S. G. Walker ◽  
C. Bembrick ◽  
E. Budding
Keyword(s):  
Light Curve ◽  
Main Sequence ◽  
General Trend ◽  
Detailed Review ◽  
Binary Solutions ◽  
Short Period ◽  
Type Contact ◽  
Contact Binary ◽  
Low Mass ◽  
Period Decrease

AbstractPhotometry of the short-period (P ∼0.285 d) low-mass (M1 ∼0.67, M2 ∼0.48 M⊙) W UMa-type eclipsing binary RW Dor, mainly involving a good series of observations in 1987–88, using standard B and V filters at the Auckland Observatory, is examined. Analysis via light curve fittings alone permits both transit (near main sequence) and occultation (W-type contact binary) solutions. Consideration of proximity or other effects on the relatively small number of measured radial velocities gives rise to a more detailed review of the alternatives, though the (W-type) configuration determined by Hilditch, Hill & Bell (1992) is still confirmed. Further implications of this configuration are examined, given an apparent general trend to period decrease (Δ P/P ∼6 × 10−11), and some light curve asymmetry. This is consistent with the initially low-mass companion, Case-B scenario of Budding (1984). The evidence does suggest irregularity of the period variation however, and further detailed surveillance, including more spectroscopy, is desirable.

scholarly journals Progress report on the monitoring active late-type stars in 2005/2006 and the analysis of V523 Cas

2006 ◽  
pp. 89-94 ◽  
Author(s):  
M. Zboril ◽  
G. Djurasevic
Keyword(s):  
Light Curve ◽  
Progress Report ◽  
Curve Analysis ◽  
Light Curves ◽  
Late Type ◽  
Light Curve Analysis ◽  
Middle Latitudes ◽  
Theoretical Considerations

We present the light curve analysis of late-type binary V523 Cas for the season 2005. The spot has been revealed on the secondary. According to theoretical considerations, the spot appeared to be hotter than the surrounding photosphere and located at middle latitudes (the radius 40? and latitude 48?). The light curves for other stars in the observational list (many of them again with O'Connell effect), for the same season, have been made electronically available. These objects are SV Cam, IV Dra, BI Vul, DD Com, 12 Cam and II Peg.

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