- ID:
- ivo://CDS.VizieR/J/A+A/445/617
- Title:
- V823 Cas BV(RI)c differential photometry
- Short Name:
- J/A+A/445/617
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using extended multicolour CCD photometry of the triple-mode radial pulsator V823 Cas we studied the properties of the coupling frequencies invoked by nonlinear processes. Our results support that a resonance connection affects the mode coupling behaviour. The P1/P0 period ratio of V823 Cas has an "out of range" value if compared with the period ratios of the known double mode pulsators, while the P2/P1 period ratio is normal. The periods and period ratios cannot be consistently interpreted without conflict with pulsation and/or evolution models. We describe this failure with the suggestion that at present, the periods of V823 Cas are in a transient, resonance affected state, thus do not reflect the true parameters of the object. The anomalous period change behaviour of the fundamental and second overtone modes supports this idea. We have also raised the possibility that a f0+f2=2f1 resonance may act in triple mode pulsators.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/other/RAA/17.20
- Title:
- V977 Cep and V982 Cep long-term photometry
- Short Name:
- J/other/RAA/17.2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Long-term BVRI photometric light curves of the pre-main sequence stars V977 Cep and V982 Cep during the period from 2000 October to 2016 August are presented. The stars are located in the vicinity of the reflection nebula NGC 7129. Our photometric data show that both stars exhibit strong photometric variability in all optical passbands, which is typical for Classical T Tauri stars. Using our observational data we analyze the reasons for the observed brightness variations. In the case of V977 Cep we identify previously unknown periodicity in its light curve.
- ID:
- ivo://CDS.VizieR/J/other/RAA/14.1264
- Title:
- V350 Cep UBVRI long-term photometry
- Short Name:
- J/other/RAA/14.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results from UBVRI optical photometric observations of the pre-main sequence star V350 Cep during the period 2004-2014 are presented. The star was discovered in 1977 due to its remarkable increase in brightness by more than 5mag (R). In previous studies, V350 Cep is considered to be a potential FUor or EXor eruptive variable. Our data suggest that during the period of observations the star keeps its maximum brightness with low amplitude photometric variations. Our conclusion is that V350 Cep is probably an intermediate object between FUors and EXors, similar to V1647 Ori.
- ID:
- ivo://CDS.VizieR/J/A+A/350/513
- Title:
- V368 Cep UBVRI time series
- Short Name:
- J/A+A/350/513
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our time series analysis of V368 Cep photometry ascertains the rotation period of 2.74d uniquely. The manifestations of starspot induced luminosity variations in this chromospherically active star include rapid light curve changes and differential rotation of about 3%. We conclude that the single rapidly rotating variable V368 Cep is a high inclination K1V post T Tauri star.
- ID:
- ivo://CDS.VizieR/J/A+A/542/A43
- Title:
- V2493 Cyg BVRI long term photometry
- Short Name:
- J/A+A/542/A43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new results from optical photometric and spectroscopic observations of the eruptive pre-main sequence star V2493 Cyg (HBC 722). The object has continued to undergo significant brightness variations over the past few months and is an ideal target for follow-up observations.
- ID:
- ivo://CDS.VizieR/J/PAZh/42/831
- Title:
- V1027 Cygni UBV and JHKLM photometry
- Short Name:
- J/PAZh/42/831
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of our UBV and JHKLM photometry for the semiregular pulsating variable V1027 Cyg, a supergiant with an infrared excess, over the period from 1997 to 2015 (UBV) and in 2009-2015 (JHKLM). Together with the new data, we analyze the photometric observations of V1027 Cyg that we have obtained and published previously. Our search for a periodicity in the UBV brightness variations has led to several periods from P=212d to 320d in different time intervals. We have found the period P=237d based on our infrared photometry. The variability amplitude, the lightcurve shape, and the magnitude of V1027 Cyg at maximum light change noticeably from cycle to cycle.
- ID:
- ivo://CDS.VizieR/J/PAZh/41/148
- Title:
- V1329 Cyg UBV light curves and spectrum
- Short Name:
- J/PAZh/41/148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The photoelectric UBV observations of the peculiar symbiotic star V1329 Cyg performed at the Crimean Station of the SAI-MSU during 245 nights over the period 2003-2014 are presented. The star's light curves since 1973 from the Crimean observations are shown. The brightness decline after its outburst over the last 40 years was 0.8m-1.0m. The phase color curves at phases 0.2 and 0.8 have maxima. Their qualitative interpretation in terms of the model of interacting winds in symbiotic binary star systems is proposed. The orbital period of the binary system has been redetermined. The spectroscopic observations at the 125-cm telescope of the Crimean Station from 1994 to 2014 have confirmed the change in the system's emission spectrum with orbital phase.
- ID:
- ivo://CDS.VizieR/J/A+AS/139/513
- Title:
- 1975-1995 V1794 Cyg UBVRI photometry
- Short Name:
- J/A+AS/139/513
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Six years of new photometry of V 1794 Cyg is combined with the previously published data. These data are processed into two decades of homogeneous standard Johnson UBVRI photometry, which contains 1207, 1837, 1927, 867 and 75 observations in U, B, V, R and I, respectively.
- ID:
- ivo://CDS.VizieR/J/AJ/146/112
- Title:
- V light curve of RW Aur
- Short Name:
- J/AJ/146/112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- RW Aur A is a classical T Tauri star, believed to have undergone a reconfiguration of its circumstellar environment as a consequence of a recent flyby of its stellar companion, RW Aur B. This interaction stripped away part of the circumstellar disk of RW Aur A, leaving a tidally disrupted "arm" and a short truncated circumstellar disk. We present photometric observations of the RW Aur system from the Kilodegree Extremely Little Telescope survey showing a long and deep dimming that occurred from 2010 September until 2011 March. The dimming has a depth of ~2mag, a duration of ~180 days, and was confirmed by archival observations from American Association of Variable Star Observers. We suggest that this event is the result of a portion of the tidally disrupted disk occulting RW Aur A, specifically a fragment of the tidally disrupted arm. The calculated transverse linear velocity of the occulter is in excellent agreement with the measured relative radial velocity of the tidally disrupted arm. Using simple kinematic and geometric arguments, we show that the occulter cannot be a feature of the RW Aur A circumstellar disk, and we consider and discount other hypotheses. We also place constraints on the thickness and semimajor axis of the portion of the arm that occulted the star.
- ID:
- ivo://CDS.VizieR/J/A+A/582/L12
- Title:
- V960 Mon light curves
- Short Name:
- J/A+A/582/L12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We monitored the recent FUor 2MASS J06593158-0405277 (V960 Mon) since November 2009 at various observatories and multiple wavelengths. After the outburst by nearly 2.9mag in r around September 2014 the brightness gently fades until April 2015 by nearly 1mag in U and 0.5mag in z. Thereafter the brightness at {lambda}>5000{AA} was constant until June 2015 while the shortest wavelengths (U,B) indicate a new rise, similar to that seen for the FUor V2493 Cyg (HBC722). Our near-infrared (NIR) monitoring between December 2014 and April 2015 shows a smaller outburst amplitude (~2mag) and a smaller (0.2-0.3mag) post-outburst brightness decline. Optical and NIR color-magnitude diagrams indicate that the brightness decline is caused by growing extinction. The post-outburst light curves are modulated by an oscillating color-neutral pattern with a period of about 17 days and an amplitude declining from ~0.08mag in October 2014 to ~0.04mag in May 2015. The properties of the oscillating pattern lead us to suggest the presence of a close binary with eccentric orbit.