Observations and light curve solutions of the eclipsing binaries KR Lyn, CSS J110212+244412, NSVS 4917488 and NSVS 7336024

Serbian Astronomical Journal ◽

10.2298/saj170921001k ◽

2018 ◽

pp. 21-27 ◽

Cited By ~ 1

Author(s):

D. Kjurkchieva ◽

V.A. Popov ◽

J. Eneva ◽

N. Petrov

Keyword(s):

Light Curve ◽

Eclipsing Binaries ◽

Type Star ◽

Eclipsing Stars ◽

Photometric Observations ◽

Short Period

We present photometric observations in Sloan filters g?, i? of the short-period eclipsing stars KR Lyn, CSS J110212+244412, NSVS 4917488 and NSVS 7336024. The light curve solutions revealed that all targets are overcontact binaries whose components are G and K stars. Their temperature differences do not exceed 300 K but they differ considerably in size and mass. NSVS 4917488 and NSVS 7336024 reveal total eclipses and their parameters can be considered as well-determined. We found that KR Lyn, NSVS 4917488 and NSVS 7336024 are of W-subtype while CSS J110212+244412 is A-subtype W UMa-type star.

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Observations and light curve solutions of the eclipsing binaries USNO-B1.0 1395-0370184 and USNO-B1.0 1395-0370731

Serbian Astronomical Journal ◽

10.2298/saj160328005k ◽

2016 ◽

pp. 27-32 ◽

Cited By ~ 1

Author(s):

D. Kjurkchieva ◽

V.A. Popov ◽

D. Vasileva ◽

N. Petrov

Keyword(s):

Light Curve ◽

Eclipsing Binaries ◽

Eclipsing Stars ◽

System P ◽

Photometric Observations ◽

Short Period ◽

Orbital Periods ◽

Period System

We present follow-up photometric observations in Sloan filters g', i' of the newly discovered eclipsing stars USNO-B1.0 1395-0370184 and USNO-B1.0 1395-0370731. Our data revealed that their orbital periods are considerably bigger than the previous values. This result changed the classification of USNO-B1.0 1395-0370184 from ultrashort-period binary (P=0.197 d) to short-period system (P=0.251 d). The light curve solutions of our observations revealed that USNOB1.0 1395-0370184 and USNO-B1.0 1395-0370731 are overcontact binaries in which components are K dwarfs, close in masses and radii. The light curve distortions were reproduced by cool spots with angular radius of around 20?.

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Spectroscopic and photometric observations of the short-period RS CVn-type star CG Cyg

Astronomy and Astrophysics ◽

10.1051/0004-6361:20030040 ◽

2003 ◽

Vol 400 (2) ◽

pp. 623-631 ◽

Cited By ~ 17

Author(s):

D. P. Kjurkchieva ◽

D. V. Marchev ◽

W. Ogloza

Keyword(s):

Type Star ◽

Photometric Observations ◽

Short Period

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Global parameters of the newly-discovered W UMa stars WISEJ004327.7+722407 and WISEJ234557.8+510456

Serbian Astronomical Journal ◽

10.2298/saj2000019k ◽

2020 ◽

pp. 19-23

Author(s):

D. Kjurkchieva ◽

S. Ibryamov

Keyword(s):

Light Curve ◽

Spectral Type ◽

Eclipsing Binaries ◽

Light Levels ◽

Photometric Observations ◽

Global Parameters

Photometric observations in g' and i' bands of the newly-discovered W UMa stars WISEJ004327.7+722407 and WISEJ234557.8+510456 are presented. The two targets are with shallow-contact configurations and their components are of G{K spectral type. We found that WISEJ004327.7+722407 is of A subtype while WISEJ234557.8+510456 is of W subtype. The different light levels at the quadratures were reproduced by cool spots on the bigger components. The procedure for calculation of the global parameters of eclipsing binaries by light curve solutions and GAIA distances was refined for stars with deep eclipses. The obtained global parameters reveal that at least one of the components of WISEJ004327.7+722407 and WISEJ234557.8+510456 is oversized, overluminous and too hot compared with an MS star with the same mass.

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Spectroscopic and Photometric Observations of the Short-Period RS CVn-Type Star UV Piscium

The Astronomical Journal ◽

10.1086/427396 ◽

2005 ◽

Vol 129 (2) ◽

pp. 1084-1095 ◽

Cited By ~ 12

Author(s):

Diana P. Kjurkchieva ◽

Dragomir V. Marchev ◽

Paul A. Heckert ◽

James I. Ordway

Keyword(s):

Type Star ◽

Photometric Observations ◽

Short Period

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Observations and Light Curve Solutions of Ultrashort-Period Eclipsing Binaries

Publications of the Astronomical Society of Australia ◽

10.1017/pasa.2017.68 ◽

2018 ◽

Vol 35 ◽

Cited By ~ 8

Author(s):

Diana P. Kjurkchieva ◽

Dinko P. Dimitrov ◽

Sunay I. Ibryamov ◽

Doroteya L. Vasileva

Keyword(s):

Light Curve ◽

Temperature Difference ◽

Empirical Relation ◽

Eclipsing Binaries ◽

Linear Relations ◽

Type Iii ◽

Photometric Observations ◽

Low Dispersion ◽

Orbital Axis

AbstractPhotometric observations in V and I bands and low-dispersion spectra of 10 ultrashort-period binaries (NSVS 2175434, NSVS 2607629, NSVS 5038135, NSVS 8040227, NSVS 9747584, NSVS 4876238, ASAS 071829-0336.7, SWASP 074658.62+224448.5, NSVS 2729229, NSVS 10632802) are presented. One of them, NSVS 2729229, is newly discovered target. The results from modelling and analysis of our observations revealed that (i) eight targets have overcontact configurations with considerable fill-out factor (up to 0.5), while NSVS 4876238 and ASAS 0718-03 have almost contact configurations; (ii) NSVS 4876238 is rare ultrashort-period binary of detached type; (iii) all stellar components are late dwarfs; (iv) the temperature difference of the components of each target does not exceed 400 K; (v) NSVS 2175434 and SWASP 074658.62 + 224448.5 exhibit total eclipses and their parameters could be assumed as well determined; (v) NSVS 2729229 shows emission in the Hα line. Masses, radii, and luminosities of the stellar components were estimated by the empirical relation ‘period, orbital axis’ for short- and ultrashort-period binaries. We found linear relations mass–luminosity and mass–radius for the stellar components of our targets.

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A Study of the Short-Period Cepheid EU Tauri

International Astronomical Union Colloquium ◽

10.1017/s0252921100109212 ◽

1985 ◽

Vol 82 ◽

pp. 98-99

Author(s):

W. P. Gieren

Keyword(s):

Light Curve ◽

Velocity Curve ◽

Radial Velocities ◽

Correlation Technique ◽

Fourier Decomposition ◽

Classical Cepheid ◽

Photometric Observations ◽

Short Period ◽

Johnson System ◽

Better Than

EU Tauri is a classical Cepheid with one of the shortest period known. A Fourier decomposition study of its V light curve by Simon S Lee (1981) revealed a peculiar position in phase-period diagrams, very similar to the star SU Cas which is probably an overtone pulsator (Gieren, 1982). This suggested the possibility that EU Tau might be another galactic overtone pulsator. In order to investigate this question, some 100 new photometric observations of this star on the UBVRI (Johnson) system were obtained with the #2 0.9m telescope of KPNO. Simultaneously, 43 CCD spectra of the star were secured on the Coudé feed telescope of KPNO which were measured for radial velocities using a correlation technique. These velocities have an internal accuracy of better than 0.5 km/s and define a complete velocity curve of EU Tau.

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