15
Preliminary discussion on IU Per L. Hric, E. Kundra Astronomical Institute of the Slovak Academy of Sciences, 059 60 Tatranská Lomnica, Slovak Republic KOLOS 2011
Preliminary discussion on IU Per
L. Hric, E. Kundra
Astronomical Institute of the Slovak Academy of Sciences,
059 60 Tatranská Lomnica, Slovak Republic
KOLOS 2011
IU Persei is an eclipsing semi - detached binary with pulsating component. Using our photometric CCD observations in B and V filters we introduce the model of this system in detail. We determined the (O - C) diagram behaviour and geometric and physical parameters of semi – detached system. We detected the short – term variations on the light curve. What's more, we obtained the residua, by comparison of observational and synthetic light curves, of which the detailed period analysis enabled to characterize and localize their source. We explain these variations as the pulsation activity of the primary component typical for the Delta Scuti Stars.
Abstract
Outline
IU Per – overview of the system
Long-term photometric behaviour (activity, BV photometry, period analysis, discovery of 0.3 – 0.65 hours period)
Period analysis of IU Per and pulsation periods
Monitoring of (O – C) diagram
Conection with AG Dra
IU Per – overview of the system
IU Per – overview of the system
Observations
(O – C)
Qian et al. (2001)
By Fitsch (1981) we calculated for the average density of the primary of IU Per and selected periods of pulsations ((0.0125 d, 0.0167 d, 0.0208 d, 0.025 d) we calculated the following values of pulsation constant 0.00635, 0.00846, 0.01058, 0.01270
Fitch (1981) From published models of pulsations of the stars of type sigma scuti (Fitch 1981) we identified for the pulsation constants 0.01058 and 0.01270 the following modes of pulsations: The fifth harmonic radial mode of pulsations 5HThe sixth harmonic non-radial mode of pulsations p7
Resonance in AG DraWe discovered the resonance 14/9 between orbital and pulsation periods.
P orbital = (549.8 ± 0.8) days x 9 = 4948.2 ± 7.2
P pulsation = (352.8 ± 1.1) days x 14 = 4939.2 ± 15.4
42000 43000 44000 45000 46000 47000 48000 49000 50000 51000 52000 53000JD - 2400000 [days]
-160
-150
-140
Ra
dia
l ve
loc
ity
[k
m.s
-1
]
12.0
11.0
10.0
9.0
B [
ma
g]
AG Dra Radial velocity
V
U
B
orb ita l responsepulsation response
orb ita l + pu lsa tion response
12.0
11.0
10.0
9.0
8.0
U [m
ag
]
10.0
9.0
8.0 V [m
ag
]
Thank you for
your attention
