scholarly journals Photometry of the δ Scuti Star DG Leo: Preliminary Results

2004 ◽  
Vol 191 ◽  
pp. 73-74 ◽  
Author(s):  
P. Lampens ◽  
R. Garrido ◽  
L. Parrao ◽  
J.H. Peña ◽  
T. Arentoft ◽  
...  
Keyword(s):  
Orbital Period ◽  
Noise Level ◽  
Amplitude Spectrum ◽  
Slow Variation ◽  
Photoelectric Photometry ◽  
Period Analysis ◽  
Preliminary Results ◽  
Spectroscopic Binary ◽  
Scuti Star ◽  
Triple Star

AbstractNew uvby photoelectric photometry has been acquired for the triple star DG Leo at two different observatories equipped with analogous instrumentation. A preliminary period analysis indicates the presence of at least 3 close δ Scuti frequencies (10-12 c/d, 3-6 mmag) and a slow variation. This slow variation fits quite well with half the orbital period of the spectroscopic binary; the noise level in the amplitude spectrum is only 3–4 mmag (after prewhitening).

scholarly journals Study of Eclipsing Binary and Multiple Systems in OB Associations IV: Cas OB6 Member DN Cas

2016 ◽  
Vol 33 ◽  
Author(s):  
V. Bakış ◽  
H. Bakış ◽  
S. Bilir ◽  
Z. Eker
Keyword(s):  
Orbital Period ◽  
Early Type ◽  
Eccentric Orbit ◽  
Period Analysis ◽  
Multiple Systems ◽  
Spectroscopic Binary ◽  
Short Period ◽  
Synchronous Rotation ◽  
The Masses ◽  
Absolute Parameters

AbstractAn early-type, massive, short-period ($P_{\text{orb}}=2^d.310951$) eclipsing spectroscopic binary DN Cas has been re-visited with new spectral and photometric data. The masses and radii of the components have been obtained as $M_1=19.04\pm 0.07\,\text{M}_\odot$, $M_2=13.73\pm 0.05\,\text{M}_\odot$ and $R_1=7.22\pm 0.06\,\text{R}_\odot$, $R_2=5.79\pm 0.06\,\text{R}_\odot$, respectively. Both components present synchronous rotation ($V_{\text{rot}1}=160\,\text{km } \text{s}^{-1}$, $V_{\text{rot}2}=130\ \text{km} \,\text{s}^{-1}$) with their orbit. Orbital period analysis yielded a physically bound additional component in the system with a minimum mass of $M_3=0.88\,\text{M}_\odot$ orbiting in an eccentric orbit (e = 0.37 ± 0.2) with an orbital period of P12 = 42 ± 9 yr. High precision absolute parameters of the system allowed us to derive a distance to DN Cas as 1.7 ± 0.2 kpc which locates the system within the borders of the Cas OB6 association (d = 1.8 kpc). The space velocities and the age of DN Cas are in agreement with those of Cas OB6. The age of DN Cas (τ = 3–5 Myr) is found to be 1–2 Myr older than the embedded clusters (IC 1795, IC 1805, and IC 1848) in the Cas OB6 association, which implies a sequential star formation in the association.

scholarly journals Ultraviolet Observations of Cataclysmic Variables

1987 ◽  
Vol 93 ◽  
pp. 205-205 ◽  
Author(s):  
F. Verbunt
Keyword(s):  
Orbital Period ◽  
Cataclysmic Variables ◽  
Type Systems ◽  
Terminal Velocity ◽  
Dwarf Novae ◽  
Preliminary Results ◽  
System Type ◽  
International Ultraviolet Explorer ◽  
Flux Level ◽  
Ultraviolet Observations

AbstractThe preliminary results of the analysis of more than 1000 spectra of cataclysmic variables in the archive of the International Ultraviolet Explorer were presented at the meeting. To characterize the slope of the spectra I use F = log(f1460Å/f2880Å). For most spectra F lies between 0.2 and 0.7. No correlation of F with orbital period, inclination, system type or (for dwarf novae) length of the interoutburst interval are found, apart from somewhat lower values of F for DQ Her type systems. Out of 16 dwarf novae for which spectra both at outburst maximum and minimum are available 11 show no large difference in F between maximum and minimum, and in 5 F declines with the flux level. Out of 6 dwarf novae 5 show very red spectra during the rise to maximum, and 1 shows slopes during rise similar to those during decline.In the ultraviolet resonance lines, due to a wind from the disc, no correlation is found between inclination and terminal velocity.

First Results of the 17th DSN Campaign: Photometry of XX Pyx

2000 ◽  
Vol 176 ◽  
pp. 469-470
Author(s):  
T. Arentoft ◽  
G. Handle ◽  
R. R. Shobbrook ◽  
M. A. Wood ◽  
L. Crause ◽  
...  
Keyword(s):  
Time Series ◽  
Amplitude Spectrum ◽  
Detection Level ◽  
First Results ◽  
Scuti Star ◽  
Delta Scuti

AbstractWe present the first results from multi-site observations of the δ Scuti star XX Pyx (CD–24°7599). The observations were carried out as the 17th run of the Delta Scuti Network. We collected 583 hr of B, V time-series photometry, resulting in a detection level (4σ) in the amplitude spectrum of 0.5 mmag. We detect 6 new pulsation frequencies, bringing the total number of frequencies known in this star up 19.

scholarly journals Multiperiodicity in light variations of 53 Persei: results from optical photometry in 1990 October–1991 January

1994 ◽  
Vol 162 ◽  
pp. 33-36
Author(s):  
L. Huang ◽  
Z. Guo ◽  
J. Hao ◽  
J.R. Percy ◽  
M.S. Fieldus ◽  
...  
Keyword(s):  
Line Profile ◽  
Separate Group ◽  
Single Site ◽  
Optical Observations ◽  
Optical Photometry ◽  
Period Analysis ◽  
Preliminary Results ◽  
Rotational Modulation ◽  
Uv Photometry ◽  
Nonradial Pulsation

The B type star 53 Persei was discovered in 1977 by Smith (1977) as the prototype of a separate group of B-type variables showing light and line profile variability. The physical cause of the variability was thought to be nonradial pulsation (NRP) (see, e.g. Smith et al. 1984). However, the NRP model for this star has been questioned by Balona (1986) who suggested the rotational modulation (RM) model to explain the variability. In order to resolve the long lasting debate about 53 Persei, a campaign was initiated to organize coordinated optical photometry and spectroscopy from the ground, and Far-UV photometry from Voyager in 1991 January. This paper presents the results of period analysis on the groundbased UBV data. In another paper, Smith & Huang (1994) report the new identification of pulsation modes using Voyager Far-UV photometry combined with the results from optical observations. Some preliminary results from APT uvby observations taken at a single site are also cited for comparison.

scholarly journals Multiwavelength Variability in the Symbiotic Nova V1016 CYG

2004 ◽  
Vol 194 ◽  
pp. 224-224
Author(s):  
Š. Parimucha ◽  
M. Vańko
Keyword(s):  
Binary System ◽  
Light Curve ◽  
Orbital Period ◽  
Uv Spectroscopy ◽  
Infrared Photometry ◽  
Symbiotic System ◽  
Photoelectric Photometry ◽  
Mira Variable ◽  
Multiwavelength Variability

Analysis of the optical and infrared photometry together with UV spectroscopy led to discovery of the 15-years periodicity in the symbiotic system V1016 Cyg. This period could be interpreted as a orbital period in the binary system consisting of the Mira variable and the hot white dwarf.We have analyzed long-term optical photographic and UBV photoelectric photometry of V1016 Cyg. Collected observations cover pre- and post-outburst stages of the system. The light, curve suggests four stages of activity: the pre-out burst flare in 1949, the main nova-like outburst in 1904, and two post-outbursts, decreasing-amplitude flares in 1980 and 1994, respectively. Activity episodes affecting the system repeat with an interval of ~ 15 years. The ephemeris for the activity maxima is (see Parimucha et al., 2000).

scholarly journals Harmonics and Coupling-terms in the Pulsation of the Double-mode Cepheid TU Cas

1993 ◽  
Vol 139 ◽  
pp. 372-372
Author(s):  
L. Szabados
Keyword(s):  
Fundamental Mode ◽  
Temporal Variations ◽  
Linear Combinations ◽  
Period Analysis ◽  
Preliminary Results ◽  
Coupling Terms

AbstractPreliminary results of the period analysis of the double-mode Cepheid TU Cassiopeiae are given. Up to now 29 frequencies have been identified: the frequency of the fundamental mode pulsation and the first overtone, and their linear combinations. The amplitudes of the frequency constituents show temporal variations.

scholarly journals A Search for Rotationally Modulated Hα Variability in OB Supergiants

2004 ◽  
Vol 215 ◽  
pp. 45-46
Author(s):  
T. Morel ◽  
S. V. Marchenko ◽  
A. K. Pati ◽  
K. Kuppuswamy ◽  
M. T. Carini ◽  
...  
Keyword(s):  
Line Profile ◽  
Large Scale ◽  
Causal Link ◽  
Period Analysis ◽  
Preliminary Results ◽  
Spectroscopic Monitoring

We present preliminary results of a long-term spectroscopic monitoring of a magnitude-limited (V < 7.5) sample of OB-supergiants (07.5-B9) aimed at establishing the incidence of co-rotating, large-scale wind structures. In the optical, this can be achieved by detecting rotationally modulated variability in Hα. Dramatic line-profile variations operating on a daily (and in some cases on a hourly) timescale are observed. Firm conclusions regarding the origin of the variability must, however, await a detailed period analysis. There is no clear evidence for a causal link between photospheric and wind activities.

First orbital period analysis of the Algol-type eclipsing binary RZ Aurigae

New Astronomy ◽  
2010 ◽  
Vol 15 (4) ◽  
pp. 392-395 ◽  
Author(s):  
Y.-G. Yang ◽  
H.-F. Dai ◽  
X.-G. Yin
Keyword(s):  
Orbital Period ◽  
Period Analysis ◽  
Eclipsing Binary

scholarly journals Dynamical investigations of the multiple stars

2017 ◽  
Vol 26 (1) ◽  
Author(s):  
Olga V. Kiyaeva ◽  
Roman Ya. Zhuchkov
Keyword(s):  
High Precision ◽  
Orbital Period ◽  
Triple System ◽  
Main Sequence ◽  
Double Star ◽  
Multiple Stars ◽  
Ccd Observations ◽  
Triple Star

AbstractTwo multiple stars - the quadruple star - Bootis (ADS 9173) and the triple star T Taury were investigated. The visual double star - Bootiswas studied on the basis of the Pulkovo 26-inch refractor observations 1982-2013. An invisible satellite of the component A was discovered due to long-term uniform series of observations. Its orbital period is 20 ± 2 years. The known invisible satellite of the component B with near 5 years period was confirmed due to high precision CCD observations. The astrometric orbits of the both components were calculated. The orbits of inner and outer pairs of the pre-main sequence binary T Taury were calculated on the basis of high precision observations by the VLT and on the Keck II Telescope. This weakly hierarchical triple system is stable with probability more than 70%.

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