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Journal "Peremennye Zvezdy"
Peremennye Zvezdy

Peremennye Zvezdy (Variable Stars) 33, No. 4, 2013

Received 04 June; accepted 25 June.

Article in PDF

New Eclipsing Variable Star with Delta Scuti Component

V. Solovyov1, A. Samokhvalov2,3, B. Satovskiy3

  1. Kazan Federal University, Russia, e-mail: solo.vya@gmail.com;

  2. Surgut, Russia, e-mail: sav@surgut.ru;

  3. Astrotel Observatory, Carachay-Cherkessiya, Russia; e-mail: bsatovski@gmail.com


We present our discovery a new variable star USNO-A2.0 1350-17086180 from observations at the Astrotel-Caucasus Observatory. The object shows Algol-type eclipses and, simultaneously, low-amplitude, short-period pulsations.

1. Introduction

During observations of a field in Cepheus, we discovered a new Algol-type variable star with a pulsating Scuti component: USNO-A2.0 1350-17086180 ( , , J2000, 2MASS), with the () variability range. For the finding chart of the star, see Fig. 1. Using an extensive series of observations, we determined parameters of the photometric behavior of the system.

2. Observations and data reduction

Our observations were carried out at the Astrotel-Caucasus observatory, located at the Astronomical station of the Kazan Federal University in the Northern Caucasus, using a 300-mm Ritchey-Chretien telescope equipped with an unfiltered Apogee Alta U9000 CCD camera. A total of 2058 images with 5-minute exposures were obtained during 45 nights between JD 2455828 and JD 2456219. The numbers of observations on each of the observing nights are presented in Table 1; the observations are attached to the html version of this paper.

Table 1. Numbers of observations

Night
JD No.of Night JD No. of Night JD No. of
No. observations No. observations No. observations

1
2455828 11 16 2455925 40 31 2456185 48
2 2455833 50 17 2455926 20 32 2456186 48
3 2455842 50 18 2455930 38 33 2456188 28
4 2455843 60 19 2455956 28 34 2456189 52
5 2455873 72 20 2456109 7 35 2456190 51
6 2455879 75 21 2456115 19 36 2456195 44
7 2455880 95 22 2456116 5 37 2456196 45
8 2455881 72 23 2456153 21 38 2456197 2
9 2455883 85 24 2456173 2 39 2456200 44
10 2455884 55 25 2456174 40 40 2456201 48
11 2455888 29 26 2456175 42 41 2456202 52
12 2455895 35 27 2456177 40 42 2456216 95
13 2455900 73 28 2456182 53 43 2456217 72
14 2455901 75 29 2456183 45 44 2456218 70
15 2455902 12 30 2456184 44 45 2456219 24


For basic reductions for dark current, flat fields, bias and for removing cosmic rays hits, we used IRAF routines. For photometry of the new variable star, we applied VaST software by Sokolovsky and Lebedev (2005). The comparison star was USNO-A2.0 1350-17114431 = USNO-B1.0 1368-0511417 ( , , J2000, 2MASS; , , USNO-B1.0).

Unfiltered magnitudes were calibrated using the comparison star, assuming .

All times in this paper are expressed in terrestrial time in accordance with IAU recommendations (resolution B1 XXIII IAU GA).

3. Analysis of observations

3.1. Eclipses

For analysis of our photometrical observations, we used the Lafler-Kinman method (Lafler and Kinman 1965) implemented in Peranso software (http://www.peranso.com). Using this method, we determined the eclipsing system's orbital period to be . The depth of primary minima is and that of secondary minima, . The three primary minima we observed are listed in Table 2; all these times were determined using the method described by Kwee and van Woerden (1956).

Table 2. The observed primary minima

No.
HJD

1
2455881.2869 0.0006
2 2456187.4703 0.0004
3 2456219.3262 0.0004


The light elements of the primary eclipses are:


3.2. Pulsations

Using the prewhitening procedure of the Peranso software, we found the pulsation period of the  Scuti component to be . The variability amplitude is , rather typical of  Scuti stars. During our observations, we detected 101 maxima of the pulsation light curve, collected in Table 3.

Table 3. Observed maxima of pulsation light curve

No.
HJD No. HJD

1
2455842.374 0.001 0 0.000 52 2456175.426 0.003 5533 0.004
2 2455842.438 0.002 1 0.004 53 2456175.484 0.001 5534 0.002
3 2455842.499 0.002 2 0.005 54 2456177.412 0.002 5566 0.004
4 2455843.400 0.002 17 0.003 55 2456177.472 0.002 5567 0.004
5 2455843.464 0.003 18 0.007 56 2456182.345 0.005 5648 0.001
6 2455843.519 0.003 19 0.001 57 2456182.404 0.003 5649 0.000
7 2455873.193 0.003 512 0.000 58 2456182.468 0.003 5650 0.004
8 2455873.252 0.002 513 -0.001 59 2456183.427 0.002 5666 -0.001
9 2455873.314 0.002 514 0.001 60 2456183.489 0.002 5667 0.001
10 2455873.368 0.004 515 -0.005 61 2456184.393 0.004 5682 0.002
11 2455873.435 0.003 516 0.001 62 2456184.456 0.003 5683 0.005
12 2455879.277 0.002 613 0.005 63 2456185.416 0.002 5699 0.002
13 2455879.336 0.002 614 0.003 64 2456185.478 0.002 5700 0.004
14 2455879.400 0.002 615 0.007 65 2456186.384 0.002 5715 0.007
15 2455879.457 0.003 616 0.004 66 2456186.445 0.003 5716 0.008
16 2455880.171 0.003 628 -0.004 67 2456186.502 0.002 5717 0.005
17 2455880.237 0.002 629 0.002 68 2456188.483 0.002 5750 -0.001
18 2455880.295 0.002 630 -0.001 69 2456188.545 0.002 5751 0.001
19 2455880.357