- ID:
- ivo://CDS.VizieR/J/AJ/152/226
- Title:
- Radial velocities of 35 cataclysmic variables
- Short Name:
- J/AJ/152/226
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report follow-up studies of 35 recently discovered cataclysmic variables (CVs), 32 of which were found in large, automated synoptic sky surveys. The objects were selected for observational tractability. For 34 of the objects, we present mean spectra and spectroscopic orbital periods, and for one more we give an eclipse-based period. Thirty-two of the period determinations are new, and three of these refine published estimates based on superhump periods. The remaining three of our determinations confirm previously published periods. Twenty of the stars are confirmed or suspected dwarf novae with periods shorter than 3 hr, but we also find three apparent polars (AM Her stars) and six systems with P>5hr. Five of these systems have secondary stars visible in their spectra, from which we estimate distances when possible. The orbital period distribution of this sample is very similar to that of previously discovered CVs.
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- ID:
- ivo://CDS.VizieR/J/AJ/149/128
- Title:
- Radial velocities of 29 cataclysmic variables
- Short Name:
- J/AJ/149/128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report follow-up spectroscopy of 29 cataclysmic variables from the Sloan Digital Sky Survey (SDSS), 22 of which were discovered by SDSS and seven of which are previously known systems that were recovered in SDSS. The periods for 16 of these objects were included in the tabulation by Gansicke et al. While most of the systems have periods less than 2hr, only one has a period in the 80-86 minutes "spike" found by Gansicke et al., and 11 have periods longer than 3hr, indicating that the present sample is skewed toward longer-period, higher-luminosity objects. Seven of the objects have spectra resembling dwarf novae, but have apparently never been observed in outburst, suggesting that many cataclysmics with relatively low variability amplitude remain to be discovered. Some of the objects are notable. SDSS J07568+0858 and SDSS J08129+1911 were previously known to have deep eclipses; in addition to spectroscopy, we use archival data from the Catalina Real Time Transient Survey to refine their periods. We give a parallax-based distance of 195(+54,-39)pc for LV Cnc (SDSS J09197+0857), which at P_orb_=81m has the shortest orbital period in our sample. SDSS J08091+3814 shows both the spectroscopic phase offset and phase-dependent absorption found in SW Sextantis stars. The average spectra of SDSS J08055+0720 and SDSS J16191+1351 show contributions from K-type secondaries, and SDSS J080440+0239 shows a contribution from an early M star. We use these to constrain the distances. SDSS J09459+2922 has characteristics typical of a magnetic system. SDSS11324+6249 may be a novalike variable, and if so, its orbital period (99 minutes) is unusually short for that subclass.
- ID:
- ivo://CDS.VizieR/J/PAZh/39/41
- Title:
- Radial velocities of HBHA 4705-03
- Short Name:
- J/PAZh/39/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results of photometric and spectroscopic studies for the new eclipsing cataclysmic variable star HBHA 4705-03 with an orbital period of 0.1718 days are presented.
- ID:
- ivo://CDS.VizieR/J/AJ/156/231
- Title:
- Radial velocities of 2 VY Sculptoris-type CV stars
- Short Name:
- J/AJ/156/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report observations of the known cataclysmic variable star (CV) V704 And, and also confirm that the optical counterpart of the ROSAT Galactic Plane Survey source RX J2338+431 is a heretofore-neglected CV. Photometric and spectroscopic observations from MDM Observatory show both systems to be nova-like variables that exhibit dips of 4-5 mag from their mean brightnesses, establishing them as members of the VY Scl subclass. From high-state emission-line radial velocities, we determine orbital periods of 0.151424(3) days (3.63 hr) for V704 And and 0.130400(1) days (3.13 hr) for RX J2338+431. In V704 And, we find that the H{alpha} emission-line measures cluster into distinct regions on a plot of equivalent width versus full width at half-maximum, which evidently correspond to high, intermediate, and low photometric states. This allows us to assign spectra to photometric states when contemporaneous photometry is not available, an apparently novel method that may be useful in studies of other novalikes. Our low-state spectra of RX J2338+431 show features of an M-type secondary star, from which we estimate a distance of 890+/-200 pc, in good agreement with the Gaia DR2 (Cat. I/345) parallax.
- ID:
- ivo://CDS.VizieR/J/AJ/155/247
- Title:
- Radial velocities of 6 X-ray cataclysmic binaries
- Short Name:
- J/AJ/155/247
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We conducted time-resolved optical spectroscopy and/or time-series photometry of 15 cataclysmic binaries that were discovered in hard X-ray surveys by the Swift Burst Alert Telescope and the International Gamma-Ray Astrophysics Laboratory, with the goal of measuring their orbital periods and searching for spin periods. Four of the objects in this study are new optical identifications: Swift J0535.2+2830, Swift J2006.4+3645, IGR J21095+4322, and Swift J2116.5+5336. Coherent pulsations are detected from three objects for the first time, Swift J0535.2+2830 (1523 s), 2PBC J1911.4+1412 (747 s), and 1SWXRT J230642.7+550817 (464 s), indicating that they are intermediate polars (IPs). We find two new eclipsing systems in time-series photometry: 2PBC J0658.0-1746, a polar with a period of 2.38 hr, and Swift J2116.5+5336, a disk system that has an eclipse period of 6.56 hr. Exact or approximate spectroscopic orbital periods are found for six additional targets. Of note is the long 4.637-day orbit for Swift J0623.9-0939, which is revealed by the radial velocities of the photospheric absorption lines of the secondary star. We also discover a 12.76 hr orbital period for RX J2015.6+3711, which confirms that the previously detected 2.00 hr X-ray period from this star is the spin period of an IP, as inferred by Coti Zelati et al. (2016MNRAS.456.1913C). These results support the conclusion that hard X-ray selection favors magnetic CVs, with IPs outnumbering polars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/387/1563
- Title:
- Radial velocity curves of AE Aqr
- Short Name:
- J/MNRAS/387/1563
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-dispersion time-resolved spectroscopy of the unique magnetic cataclysmic variable AE Aqr is presented. A radial velocity analysis of the absorption lines yields K2=168.7+/-1km/s . Substantial deviations of the radial velocity curve from a sinusoid are interpreted in terms of intensity variations over the secondary star's surface. A complex rotational velocity curve as a function of orbital phase is detected which has a modulation frequency of twice the orbital frequency, leading to an estimate of the binary inclination angle that is close to 70{deg}. The minimum and maximum rotational velocities are used to indirectly derive a mass ratio of q=0.6 and a radial velocity semi-amplitude of the white dwarf of K1=101+/-3km/s. We present an atmospheric temperature indicator, based on the absorption-line ratio of FeI and CrI lines, whose variation indicates that the secondary star varies from K0 to K4 as a function of orbital phase. The ephemeris of the system has been revised, using more than 1000 radial velocity measurements, published over nearly five decades. From the derived radial velocity semi-amplitudes and the estimated inclination angle, we calculate that the masses of the stars are M1=0.63+/-0.05M_{sun}_; M2=0.37+/-0.04M_{sun}_ , and their separation is a=2.33+/-0.02R_{sun}. Our analysis indicates the presence of a late-type star whose radius is larger, by a factor of nearly 2, than the radius of a normal main-sequence star of the same mass. Finally, we discuss the possibility that the measured variations in the rotational velocity, temperature and spectral type of the secondary star as functions of orbital phase may, like the radial velocity variations, be attributable to regions of enhanced absorption on the star's surface.
- ID:
- ivo://CDS.VizieR/J/A+A/602/A53
- Title:
- R Aqr SPHERE/ZIMPOL narrow-H{alpha} image
- Short Name:
- J/A+A/602/A53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- R Aqr is a symbiotic binary system consisting of a mira variable, a hot companion with a spectacular jet outflow, and an extended emission line nebula. Because of its proximity to the Sun, this object has been studied in much detail with many types of high resolution imaging and interferometric techniques. We have used R Aqr as test target for the visual camera subsystem ZIMPOL, which is part of the new extreme adaptive optics (AO) instrument SPHERE at the Very Large Telescope (VLT). We describe SPHERE/ZIMPOL test observations of the R Aqr system taken in H{alpha} and other filters in order to demonstrate the exceptional performance of this high resolution instrument. We compare our observations with data from the Hubble Space Telescope (HST) and illustrate the complementarity of the two instruments. We use our data for a detailed characterization of the inner jet region of R Aqr. We analyze the high resolution ~=25mas images from SPHERE/ZIMPOL and determine from the H{alpha} emission the position, size, geometric structure, and line fluxes of the jet source and the clouds in the innermost region <2"(<400AU) of R Aqr. The data are compared to simultaneous HST line filter observations. The H{alpha} fluxes and the measured sizes of the clouds yield H{alpha} emissivities for many clouds from which one can derive the mean density, mass, recombination time scale, and other cloud parameters. Our H{alpha} data resolve for the first time the R Aqr binary and we measure for the jet source a relative position 45 mas West (position angle -89.5{deg}) of the mira. The central jet source is the strongest H{alpha} component with a flux of about 2.5x10^-12^erg/cm^2^/s. North east and south west from the central source there are many clouds with very diverse structures. Within 0.5" (100AU) we see in the SW a string of bright clouds arranged in a zig-zag pattern and, further out, at 1"-2", fainter and more extended bubbles. In the N and NE we see a bright, very elongated filamentary structure between 0.2"-0.7" and faint perpendicular "wisps" further out. Some jet clouds are also detected in the ZIMPOL [OI] and HeI filters, as well as in the HST-WFC3 line filters for H{alpha}, [OIII], [NII], and [OI]. We determine jet cloud parameters and find a very well defined correlation Ne{prop.to}r^-1.3^ between cloud density and distance to the central binary. Densities are very high with typical values of Ne~=3x10^5^cm^-3^ for the "outer" clouds around 300AU, Ne~=3x10^6^cm^-3^ for the "inner" clouds around 50AU, and even higher for the central jet source. The high Ne of the clouds implies short recombination or variability timescales of a year or shorter. H{alpha} high resolution data provide a lot of diagnostic information for the ionized jet gas in R Aqr. Future H{alpha} observations will provide the orientation of the orbital plane of the binary and allow detailed hydrodynamical investigations of this jet outflow and its interaction with the wind of the red giant companion.
- ID:
- ivo://CDS.VizieR/J/AN/333/242
- Title:
- Recent photometry of symbiotic stars
- Short Name:
- J/AN/333/242
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new multicolour (U,B,V,Rc,Ic) photometric observations of classical symbiotic stars, EG And, Z And, BF Cyg, CH Cyg, CI Cyg, V1329 Cyg, TX CVn, AG Dra, Draco C1, AG Peg and AX Per, carried out between 2007.1 and 2011.9. The aim of this paper is to present new data of our monitoring programme, to describe the main features of their light curves (LC) and to point problems for their future investigation. The data were obtained by the method of the classical photoelectric and CCD photometry.
- ID:
- ivo://CDS.VizieR/J/A+A/486/855
- Title:
- R light curve of DO Dra
- Short Name:
- J/A+A/486/855
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the variability of the cataclysmic variable DO Dra, on time-scales of between minutes and decades. The observations were obtained at the Korean 1m telescope at the Mt. Lemmon in 2006-2007, 14 observational runs cover 45h. Additionally, we have used 1509 patrol observations from the international AFOEV and VSOLJ databases.
- ID:
- ivo://CDS.VizieR/J/A+A/496/765
- Title:
- R light-curve of TT Ari
- Short Name:
- J/A+A/496/765
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the variability of the nova-like cataclysmic variable TT Ari, on time-scales of between minutes and months. The observations in the filter R were obtained at the 40-cm telescope of the Chungbuk National University (Korea), 51 observational runs cover 226 hours. In our analysis, we applied several methods: periodogram, wavelet, and scalegram analysis. TT Ari remained in a "negative superhump" state after its return from the "positive superhump" state, which lasted for 8 years. The ephemeris for 12 of the best pronounced minima is T_min_=BJD 2453747.0700(47)+0.132322(53)E, where numbers in digits are errors in units of the last digit. The phases of minima may reach 0.2, which reflects the non-eclipse nature of these minima. The quasi-periodic oscillations (QPO) are present with a mean "period" of 21.6min and mean semi-amplitude of 36mmag.This value is consistent with the range 15-25min reported for previous "negative superhump" states and does not support the hypothesis of secular decrease in the QPO period. Either the period, or the semi-amplitude show significant night-to-night variations. According to the position at the two-parameter diagrams (i.e. diagrams of pairs of parameters: time, mean brightness of the system, brightness of the source of QPO, amplitude, and timescale of the QPOs), the interval of observations was divided into 5 parts, showing different characteristics: 1) the "pre-outburst" stage, 2) the "rise to outburst", 3) "top of the outbursts", 4) "post- outburst QPO" state, and 5) "slow brightening". The the QPO source was significantly brighter during the 10-day outburst, than during the preceding interval. However, after the outburst, the large brightness of the QPO source still existed for about 30 days, producing the stage "4". The diagram for m_QPO_({bar}{m}) exhibits two groups in the brightness range 10.6-10.8, which correspond to larger and smaller amplitudes of the QPO. For the group "5" only, statistically significant correlations were found, for which, with increasing mean brightness, the period, amplitude, and brightness of the of QPO source also increase. The mean brightness at the "negative superhump state" varies within 10.3-11.2, so the system is brighter than at the "positive superhump" (11.3), therefore the "negative superhump" phenomenon may be interpreted by a larger accretion rate. The system is an excellent laboratory for studying processes resulting in variations on timescales of between seconds and decades and needs further monitoring at various states of activity.
