Peremennye Zvezdy

Peremennye Zvezdy (Variable Stars) 43, No. 8, 2023

Received 23 October; accepted 30 October.

Article in PDF

DOI: 10.24412/2221-0474-43-86-100

CCD Observations of Type CW Cepheids and RV Tau Stars

L. N. Berdnikov1, A. Y. Kniazev1,2,3, A. K. Dambis 1, V. V. Kravtsov1, E. N. Pastukhova4

  1. Sternberg Astronomical Institute, Moscow State University, Universitetskij pr. 13, Moscow 119992, Russia; leonid.berdnikov@gmail.com

  2. South African Astronomical Observatory, P.O. Box 9, Observatory, Cape Town, 7935 South Africa

  3. Southern African Large Telescope, P.O. Box 9, Observatory, Cape Town, 7935 South Africa

  4. Institute of Astronomy, Russian Academy of Sciences, ul. Pyatnitskaya 48, Moscow, 119017, Russia


In 2005-2014, we obtained 16568 photometric measurements in the photometric system for 64 type II Cepheids and 54 RV Tau stars using the 76-cm telescope of the South African Astronomical Observatory (SAAO, South Africa) and the 40-cm telescope of the Cerro Armazones Observatory of the Universidad Catolica del Norte (OCA, Chile). The tables of observations and the plots of light curves are presented.

From April 2005 through May 2014, we used the 76-cm telescope of South African Astronomical Observatory (SAAO, Republic of South Africa) for photoelectric and CCD observations, while the 40-cm telescope of Cerro Armazones Observatory (OCA) of the Universidad Catolica del Norte in Chile was used for CCD observations only. The , , and filters of the Kron-Cousins system (Cousins, 1976) were used. The observation and reduction techniques were described by Berdnikov et al. (2004, 2011), respectively for photoelectric and CCD observations.

We acquired a total of 10384 photometric measurements for 64 type II Cepheids and 6184 photometric measurements for 54 RV Tau-type variables. All light curves, constructed with the elements from Tables 1-2, are presented in Figures 1-12. Three-color observations are given in text files (Tables 3 - 4) in the html version of the paper.

The scatter of data points in the plots indicates that observational errors are close to 0.01. Observations of three Cepheids - ASAS 115302-2313.0, ASAS 174134-4854.6, and ASAS 185152-1333.6 - do not fit into a single light curve because of abrupt changes of their periods; in Fig. 7, we repeat these light curves taking into account the shifts of seasonal light curves for these Cepheids.

The light curves of most of the RV Tau type stars are highly unstable, resulting in times of minima deviating from the ephemerides reported in the GCVS and ASAS-3 variable-star catalogs (Table 2).

The new data obtained in this study will be used to study the structure and kinematics of the old disk and Galactic halo and also to study the properties of Cepheids and RV Tau type stars and, particular, to search for evolutionary changes in their periods.

References:

Berdnikov, L.N., Kniazev, A.Yu., Sefako, R. et al., 2011, Astron. Rep., 55, 816

Berdnikov, L.N., Turner, D.G., 2004, Astron. Astrophys. Trans., 23, 253

Cousins, A.W.J., 1976, Mem. Roy. Astron. Soc., 81, 25


Fig. 1. Light curves of type II Cepheids: V475 Ara, GK Cen, IU Cen, V415 Cen, V445 Cen, BV Cha, XY Hyi, DF Hyi, VX Ind, and UX Lup. The circles and dots show photoelectric and CCD observations, respectively.

Fig. 2. The same as in Fig. 1 but for II Nor, CE Oph, V2137 Oph, V2628 Oph, GK Sgr, V1821 Sgr, V1822 Sgr, V1828 Sgr, V1882 Sgr, V2284 Sgr, V2511 Sgr, and V2546 Sgr.

Fig. 3. The same as in Fig. 1 but for V2793 Sgr, V2944 Sgr, V3820 Sgr, V507 Sco, V516 Sco, V517 Sco, V532 Sco, V533 Sco, and V542 Sco.

Fig. 4. The same as in Fig. 1 but for V706 Sco, V708 Sco, V742 Sco, DD Vel, YZ Vir, ASAS 003041-4416.4, ASAS 044546-1748.7, ASAS 050514+2145.8, ASAS 070747-2455.2, ASAS 072845-4428.3, and ASAS 092701+1412.1.

Fig. 5. The same as in Fig. 1 but for ASAS 094844-3921.4, ASAS 104440-6003.6, ASAS 115302-2313.0, ASAS 133028-3812.5, ASAS 140434-4532.4, ASAS 142357-0100.1, ASAS 144155-1938.1, ASAS 160723-2957.2, ASAS 161115-1651.6, ASAS 164328-2122.6, ASAS 165857-4312.3, and ASAS 171022-0403.6.

Fig. 6. The same as in Fig. 1 but for ASAS 173443-1741.8, ASAS 174134-4854.6, ASAS 185152-1333.6, ASAS 190418-3142.2, ASAS 190649+2300.6, ASAS 190744-5950.7, ASAS 193606-2538.3, ASAS 193907-2049.2, ASAS 211406+0019.2, and ASAS 231839-6752.5.

Fig. 7. The same as in Fig. 1 but for ASAS 115302-2313.0, ASAS 174134-4854.6, and ASAS 185152-1333.6 with seasonal light-curve shifts taken into account.

Fig. 8. Light curves of RV Tau-type stars: DY Aql, EZ Aql, V590 Aql, RT Ara, UY Ara, V686 Ara, KO Cnc, RX Cap, GK Car, RU Cen, SX Cen, and CN Cen.

Fig. 9. The same as in Fig. 8 but for GP Cha, SY Cir, V385 CrA, V338 Lib, AS Mus, EP Mus, PX Mus, V338 Mus, V404 Nor, and TT Oph.

Fig. 10. The same as in Fig. 8 but for TX Oph, UZ Oph, V453 Oph, AR Pup, V594 Pup, V558 Sgr, V760 Sgr, V1864 Sgr, V411 Sco, V423 Sco, and AN Sct.

Fig. 11. The same as in Fig. 8 but for HI Tel, NW Tel, CY Vel, V517 Vel, ASAS 093507-4534.8, ASAS 121159-5847.0, ASAS 135914-5210.7, ASAS 154200-2046.7, ASAS 170042-3300.4, ASAS 170320-2428.9, and ASAS 171139-2328.0.

Fig. 12. The same as in Fig. 8 but for ASAS 171413-1320.7, ASAS 172055-2129.3, ASAS 174955-4019.9, ASAS 175310-1519.6, ASAS 175846+2428.4, ASAS 175934-3935.1, ASAS 181811-3533.7, ASAS 193648-3425.8, ASAS 194411-1119.5, and ASAS 202412-2457.0.



Table 1. Ephemerides for CW-type Cepheids

Cepheid Epoch, Period Cepheid Epoch, Period
JD hel 24... days JD hel 24... days
V475 Ara 36721.6336 1.50120000 V708Sco 55182.329 27.1700
GK Cen 55412.1963 1.949833 V742Sco 55005.93 14.51770
IU Cen 53336.0704 3.3192516 DDVel 55045.72 13.2075
V415 Cen 54236.79 26.6603 YZVir 54790.187 14.47271
V445 Cen 55470.70 14.2172 ASAS 003041-4416.4 54205.2546 1.90068
BV Cha 54161.9961 1.23803885 ASAS 044546-1748.7 55164.4719 0.9195727
XY Hyi 55907.484 22.1587 ASAS 050514+2145.8 53824.124 13.9410
DF Hyi 54267.0129 1.1225989 ASAS 070747-2455.2 54154.920 11.18265
VX Ind 53590.2859 1.4619446 ASAS 072845-4428.3 54526.8885 1.4377536
UX Lup 54740.410 16.25356 ASAS 092701+1412.1 55566.9273 1.3212185
II Nor 50207.66 23.5333 ASAS 094844-3921.4 54667.2918 1.2017308
CE Oph 54407.253 15.88766 ASAS 104440-6003.6 54349.02 105.833
V2137 Oph 56777.5075 1.18202240 ASAS 115302-2313.0 53855.360 15.5727
V2628 Oph 54487.34 13.3088 ASAS 133028-3812.5 53593.49 15.2940
GK Sgr 55555.692 14.86662 ASAS 140434-4532.4 55623.797 16.99892
V1821 Sgr 56784.6324 9.51627060 ASAS 142357-0100.1 55579.8951 1.3067458
V1822 Sgr 54863.00 7.52557 ASAS 144155-1938.1 55259.9049 1.0118964
V1828 Sgr 56783.50 12.99325 ASAS 160723-2957.2 55424.186 37.3283
V1882 Sgr 54908.3355 2.71119248 ASAS 161115-1651.6 54941.23 13.2261
V2284 Sgr 54688.573 1.938658 ASAS 164328-2122.6 53655.88 37.439
V2511 Sgr 56767.0966 1.72475700 ASAS 165857-4312.3 55085.865 10.99158
V2546 Sgr 54580.82 14.3905 ASAS 171022-0403.6 54780.795 15.1863
V2793 Sgr 54641.989 16.22011 ASAS 173443-1741.8 54974.20 18.1107
V2944 Sgr 54649.727 12.22564 ASAS 174134-4854.6 55456.358 10.54989
V3820 Sgr 50804.12 13.13825 ASAS 185152-1333.6 55500.7640 1.268903
V507 Sco 55021.85 11.79856 ASAS 190418-3142.2 54136.70 39.328
V516 Sco 55296.726 15.65785 ASAS 190649+2300.6 54738.974 4.839092
V517 Sco 55209.189 1.176306 ASAS 190744-5950.7 54812.2021 1.790798
V532 Sco 55131.2527 24.1493 ASAS 193606-2538.3 55434.182 9.51917
V533 Sco 56745.8888 15.52900 ASAS 193907-2049.2 55442.829 14.2869
V542 Sco 54546.653 15.23567 ASAS 211406+0019.2 55168.146 15.2634
V706 Sco 55253.224 12.63584 ASAS 231839-6752.5 55362.3226 2.5515796



Table 2. Ephemerides for RV Tau stars

Star Epoch, Period Star Epoch, Period
JD hel 24... days JD hel 24... days
DYAql 55149.47 131.86 V558Sgr 2455102.80 63.36
EZAql 55148.87 38.69 V760Sgr 2455164.45 45.16
V590 Aql 55186.41 117.38 V1864 Sgr 2455130.53 80.80
RTAra 55117.38 76.43 V411Sco 2455142.85 133.06
UYAra 55107.99 56.91 V423Sco 2455115.17 59.60
V686 Ara 55111.62 36.21 ANSct 2455217.62 65.41
KOCnc 55129.78 66.23 HITel 2455207.04 66.28
RXCap 55163.93 67.83 NWTel 2455218.33 68.99
GKCar 55197.39 55.30 CYVel 2455193.97 39.07
RUCen 55112.28 64.66 V517Vel 2455088.95 161.15
SXCen 55165.19 32.96 ASAS093507-4534.8 2455352.13 122.36
CNCen 55145.43 50.60 ASAS121159-5847.0 2455427.81 198.60
GPCha 55181.69 100.07 ASAS135914-5210.7 2455049.04 75.81
SYCir 55094.23 46.25 ASAS154200-2046.7 2455119.34 49.87
V385 CrA 55137.00 78.97 ASAS170042-3300.4 2455108.36 46.23
V338 Lib 55100.66 311.61 ASAS170320-2428.9 2454868.31 90.02
ASMus 55125.04 52.92 ASAS171139-2328.0 2454850.62 53.07
EPMus 55075.43 42.65 ASAS171413-1320.7 2455060.13 56.02
PXMus 55028.92 58.91 ASAS172055-2129.3 2455186.22 68.78
V338 Mus 54929.83 206.41 ASAS174955-4019.9 2455150.58 60.85
V404 Nor 55100.52 53.64 ASAS175310-1519.6 2455180.44 58.98
TTOph 55089.32 60.95 ASAS175846+2428.4 2454803.51 94.74
TXOph 54980.78 133.59 ASAS175934-3935.1 2455194.35 61.80
UZOph 55090.23 87.40 ASAS181811-3533.7 2455117.27 70.97
V453 Oph 55070.00 81.02 ASAS193648-3425.8 2455097.67 106.37
ARPup 55254.36 76.72 ASAS194411-1119.5 2455149.13 58.65
V594 Pup 55132.62 57.93 ASAS202412-2457.0 2455179.57 51.35



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