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31. A-F type variable stars from Kepler
ID:
ivo://CDS.VizieR/J/AJ/149/68
Title:
A-F type variable stars from Kepler
Short Name:
J/AJ/149/68
Date:
03 Dec 2021 00:36:02
Publisher:
CDS
Description:
The light curves of 2768 stars with effective temperatures and surface gravities placing them near the gamma Doradus ({gamma} Dor)/delta Scuti ({delta} Sct) instability region were observed as part of the Kepler Guest Observer program from Cycles 1 through 5. The light curves were analyzed in a uniform manner to search for {gamma} Dor, {delta} Sct, and hybrid star pulsations. The {gamma} Dor, {delta} Sct, and hybrid star pulsations extend asteroseismology to stars slightly more massive (1.4-2.5M_{sun}_) than our Sun. We find 207 {gamma} Dor, 84 {delta} Sct, and 32 hybrid candidate stars. Many of these stars are cooler than the red edge of the {gamma} Dor instability strip as determined from ground-based observations made before Kepler. A few of our {gamma} Dor candidate stars lie on the hot side of the ground-based {gamma} Dor instability strip. The hybrid candidate stars cover the entire region between 6200K and the blue edge of the ground-based {delta} Sct instability strip. None of our candidate stars are hotter than the hot edge of the ground-based {delta} Sct instability strip. Our discoveries, coupled with the work of others, show that Kepler has discovered over 2000 {gamma} Dor, {delta} Sct, and hybrid star candidates in the 116 square degree Kepler field of view. We found relatively few variable stars fainter than magnitude 15, which may be because they are far enough away to lie between spiral arms in our Galaxy, where there would be fewer stars.
32. AGAPE catalogue of M31 variables
ID:
ivo://CDS.VizieR/J/A+A/421/509
Title:
AGAPE catalogue of M31 variables
Short Name:
J/A+A/421/509
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the AGAPE astrometric and photometric catalogue of 1579 variable stars in a 14' x 10' field centred on M31. Each variable star in the catalogue is identified as AGPVm, m running from 1 to 1579. Then are given: Fn(x,y) (F being the letter of identification of AGAPE field and n the variable star number in this field; x and y being the pixel coordinates in the reference frame), right ascension and declination for 2000.0, R_max_ magnitude at observed maximum, and L the likelihood function. When the variable star is a nova discovered by eye, no L value is given.
33. AGAPEROS: variable stars in the LMC Bar
ID:
ivo://CDS.VizieR/J/A+AS/145/11
Title:
AGAPEROS: variable stars in the LMC Bar
Short Name:
J/A+AS/145/11
Date:
21 Oct 2021
Publisher:
CDS
Description:
The 91-92 EROS-1 data set has been used to select Long Timescale and Long Period Variables (LT&LPV). We choose to perform a selection of variable objects as comprehensive as possible, independent of periodicity and of their position on the colour magnitude diagram, and produce a catalogue of 632 variable objects. Table 2 provides the parameters of the variable objects detected in this paper. They are sorted in order of increasing right ascension. The columns contains the name of the variable including the RA,DEC (J2000.0) coordinates, the number of the chip and (x,y) position, the blending flags (PhiC/Phi0)_B_, (PhiC/Phi0)_R_ in both colours, the B_EROS_ and R_EROS_ magnitude, the number of star N_star_B, N_star_R found in the superpixel, the magnitude B_EROS_DAO and R_EROS_DAO estimated with DAOPHOT, and when available the cross-identifications with previous catalogue.
34. A global model for MC and Galactic Cepheids
ID:
ivo://CDS.VizieR/J/ApJ/748/107
Title:
A global model for MC and Galactic Cepheids
Short Name:
J/ApJ/748/107
Date:
21 Oct 2021
Publisher:
CDS
Description:
We perform a global fit to ~5000 radial velocity and ~177000 magnitude measurements in 29 photometric bands covering 0.3{mu}m to 8.0{mu}m distributed among 287 Galactic, Large Magellanic Cloud, and Small Magellanic Cloud Cepheids with P>10 days. We assume that the Cepheid light curves and radial velocities are fully characterized by distance, reddening, and time-dependent radius and temperature variations. We construct phase curves of radius and temperature for periods between 10 and 100 days, which yield light-curve templates for all our photometric bands and can be easily generalized to any additional band. With only four to six parameters per Cepheid, depending on the existence of velocity data and the amount of freedom in the distance, the models have typical rms light and velocity curve residuals of 0.05mag and 3.5km/s. The model derives the mean Cepheid spectral energy distribution and its derivative with respect to temperature, which deviate from a blackbody in agreement with metal-line and molecular opacity effects. We determine a mean reddening law toward the Cepheids in our sample, which is not consistent with standard assumptions in either the optical or near-IR. Based on stellar atmosphere models, we predict the biases in distance, reddening, and temperature determinations due to the metallicity and quantify the metallicity signature expected for our fit residuals.
35. AH Cam
ID:
ivo://CDS.VizieR/J/AJ/107/679
Title:
AH Cam
Short Name:
J/AJ/107/679
Date:
21 Oct 2021
Publisher:
CDS
Description:
Analysis of 746 new V-band observations of the RR Lyrae star AH Cam obtained during 1989-1992 clearly show that its light curve cannot be described by a single period. In fact, at first glance, the Fourier spectrum of the photometry resembles that of a double-mode pulsator, with peaks at a fundamental period of 0.3686d and an apparent secondary period of 0.2628d. Nevertheless, the dual-mode solution is a poor fit to the data. Rather, we believe that AH Cam is a single-mode RR Lyrae star undergoing the Blazhko effect: periodic modulation of the amplitude and shape of its light curve. What was originally taken to be the period of the second mode is instead the 1-cycle/d alias of a modulation sidelobe in the Fourier spectrum. The data are well described by a modulation period of just under 11d, which is the shortest Blazhko period reported to date in the literature and confirms the earlier suggestion by Goranskii. A low-resolution spectrum of AH Cam indicates that it is relatively metal rich, with {DELTA}S<=2. Its high metallicity and short modulation period may provide a critical test of at least one theory for the Blazhko effect. Moskalik's internal resonance model makes specific predictions of the growth rate of the fundamental mode vs fundamental period. AH Cam falls outside the regime of other known Blazhko variables and resonance model predictions, but these are appropriate for metal-poor RR Lyrae stars. If the theory matches the behavior of AH Cam for a metal-rich stellar model, this would bolster the resonance hypothesis.
36. AI CMi UBV light curves
ID:
ivo://CDS.VizieR/J/PAZh/43/460
Title:
AI CMi UBV light curves
Short Name:
J/PAZh/43/460
Date:
21 Oct 2021
Publisher:
CDS
Description:
The U BV photometry and low-resolution spectroscopy for the semiregular variable AI CMi, a candidate for post-AGB objects, performed in 1996-2016 and 2000-2013, respectively, are presented. The star showed multiperiodic brightness variations with an amplitude up to 1.5m in the V band, a significant (up to 0.4m) bluing of the B-V and U-B colors as the star faded, and a change of its spectrum from G5 I to K3-5 I, depending on its brightness. A possible long-term fading of AI CMi below 8.5m in the period from May 2013 to early 2015 is observed in the light curve. The colors in this episode did not change the pattern of their unusual behavior with brightness. The main feature of the spectrum for AI CMi is the appearance and strengthening of TiO absorption bands as its brightness declines, which are atypical in the spectra of ordinary G5-K3 supergiants. The bluing of the B-V and U-B colors is interpreted as the blanketing of stellar radiation predominantly in V (and to a lesser extent in B) by the TiO absorption bands whose intensity increases dramatically with decreasing brightness. Another cause of the bluing can be the scattering of stellar radiation by small dust particles in the gas-dust shell of AI CMi. The star's continuum-normalized spectra over the period from 2000 to 2013 in the wavelength range 4200 to 7700 or 9200{AA} are presented. These were taken at different phases of the pulsation cycle and clearly demonstrate the behavior of the TiO absorption bands depending on the V magnitude and B-V color. The equivalent widths of individual TiO bands were measured, and their correlation with the photometric parameters of the star is shown. AI CMi belongs to the O-rich branch of AGB/post-AGB supergiants and has a luminosity of ~4000L_{sun}_ at a distance of 1500+/-700pc. The mass of AI CMi is most likely small and close to the lower mass limit for post-AGB stars. The connection of the star's pulsational activity and nonstationary wind with the formation of its molecular and dust shells is discussed briefly.
37. AKARI observations of SMC Cepheids
ID:
ivo://CDS.VizieR/J/MNRAS/420/585
Title:
AKARI observations of SMC Cepheids
Short Name:
J/MNRAS/420/585
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this work we matched the AKARI archival data to the Optical Gravitational Lensing Experiment III (OGLE-III) catalogue to derive the mid-infrared period-luminosity (PL) relations for Small Magellanic Cloud (SMC) Cepheids. Mismatched AKARI sources were eliminated using random-phase colours obtained from the full I-band light curves from OGLE-III. It was possible to derive PL relations in the N3 and N4 bands only, although the S7-, S11-, L15- and L24-band data were also tested. Random-phase correction was included when deriving the PL relation in the N3 and N4 bands using the available time of observations from AKARI data. The final adopted PL relations were N3=-3.370logP+16.527 and N4=-3.402logP+16.556. However, these PL relations may be biased due to the small number of Cepheids in the sample.
38. Aldebaran radial velocity variations
ID:
ivo://CDS.VizieR/J/A+A/580/A31
Title:
Aldebaran radial velocity variations
Short Name:
J/A+A/580/A31
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the nature of the long-period radial velocity variations in {alpha} Tau first reported over 20 years ago. We analyzed precise stellar radial velocity measurements for {alpha} Tau spanning over 30 years. An examination of the H{alpha} and CaII {lambda}8662 spectral lines, and Hipparcos photometry was also done to help discern the nature of the long-period radial velocity variations.
39. Algol-type binaries. IX. V548 Cyg
ID:
ivo://CDS.VizieR/J/AJ/152/49
Title:
Algol-type binaries. IX. V548 Cyg
Short Name:
J/AJ/152/49
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a new UV light curve of the Algol eclipsing binary V548 Cyg obtained with the Lunar Ultraviolet Telescope. We model the UV light curve together with two previously published (B and V) light curves, primary star radial velocities, and eclipse timings in a unified multi-data-type solution and determine orbital parameters and absolute dimensions. Timing residuals hint at the presence of a third star in the system. This star is possibly the source of the third light that is needed to obtain a good fit to each of the light curves simultaneously. The light-time oscillation in the timing residuals has a period of either ~19 or ~46years. The third body orbit inclination would have to be low (23{deg} or 15{deg}, respectively) for the third star to have a mass of ~1.5M_{Sun}_, which would be expected for a main-sequence star of color B-V~0.32, as determined from the light curve solution. In an H-R diagram, the mass-gaining, primary component of V548 Cyg is located between the zero-age and terminal-age main sequence for solar composition stars, and close to the 0.4Gyr isochrone.
40. All Sky Automated Survey Catalog
ID:
ivo://CDS.VizieR/J/AcA/50/177
Title:
All Sky Automated Survey Catalog
Short Name:
J/AcA/50/177
Date:
21 Oct 2021
Publisher:
CDS
Description:
Results of the first two years of observations using the All Sky Automated Survey prototype camera are presented. More than 140000 stars in 50 Selected Fields covering 300 square degrees were monitored each clear night in the I-band resulting in the ASAS Photometric I-band Catalog containing over 5*10^7^ individual measurements. Nightly monitoring of over 100 standard stars confirms that most of our data remains within {sigma}_I_=0.03mag of the standard I system. Search for the stars varying on the time scales longer than a day revealed about 3800 variable stars (mostly irregular, pulsating and binaries) brighter than 13mag. Only 630 of them are known or suspected variables included in the GCVS (Kholopov 1985, Cat. <II/214>). Among the stars brighter than I~7.5 (which are saturated on our frames) we have found about 50 variables (12 are in the GCVS, 6 others in the Hipparcos catalog (Cat. <I/239>). Because of the large volume of data we present here only selected tables and light curves, but the complete ASAS Catalog of Variable Stars (currently divided into Periodic and Miscellaneous sections) and all photometric data are available on the Internet http://www.astrouw.edu.pl/~gp/asas/asas.html or http://archive.princeton.edu/~asas/

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