- ID:
- ivo://CDS.VizieR/J/other/JAD/16.1
- Title:
- GSC 8613-2122 UBVRI and uvby light curves
- Short Name:
- J/other/JAD/16.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a collection of more than 4000 UBVRI and uvby differential photometric measurements of the newly-discovered 12th-magnitude southern Delta Scuti star GSC 08613-02122. The star has a main pulsation period of about 4 hours with an amplitude of 0.05m in the V band. The pulsation amplitude is variable, and the O-C diagram reveals the existence of a long P~29.5-day cycle, which possibly results from the beating of the main pulsation frequency with a nearby frequency.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/408/475
- Title:
- HATNet Pleiades Rotation Period Catalogue
- Short Name:
- J/MNRAS/408/475
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using data from the Hungarian-made Automated Telescope Network (HATNet) survey for transiting exoplanets, we measure photometric rotation periods for 368 Pleiades stars with 0.4~<M~<1.3M_{sun}_. We detect periodic variability for 74 per cent of the cluster members in this mass range that are within our field-of-view, and 93 per cent of the members with 0.7~<M~<1.0M_{sun}_. This increases, by a factor of 5, the number of Pleiades members with measured periods. We compare these data to the rich sample of spectroscopically determined projected equatorial rotation velocities (vsini) available in the literature for this cluster. Included in our sample are 14 newly identified probable cluster members which have proper motions, photometry and rotation periods consistent with membership.
- ID:
- ivo://CDS.VizieR/J/AJ/128/1761
- Title:
- HATNET variability survey
- Short Name:
- J/AJ/128/1761
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hungarian-made Automated Telescope Network (HATnet) is an ongoing project to detect transiting extrasolar planets using small-aperture (11cm diameter) robotic telescopes. In this paper, we present the results from using image subtraction photometry to reduce a crowded stellar field observed with one of the HATnet telescopes (HAT-5). This field was chosen to overlap with the planned Kepler mission. We obtained I-band light curves for 98,000 objects in a 67 square degree field of view centered at J2000 ({alpha},{delta})=(19h44m00.0s, +37{deg}32'00.0"), near the Galactic plane in the constellations Cygnus and Lyra. These observations include 788 exposures of 5' length over 30-days. For the brightest stars (I~8.0) we achieved a precision of 3.5mmag, falling to 0.1mag at the faint end (I~14). From these light curves we identify 1617 variable stars, of which 1439 are newly discovered.
- ID:
- ivo://CDS.VizieR/J/A+A/606/A125
- Title:
- HD163296 DCO+, DCN and N_2_D+ data cubes
- Short Name:
- J/A+A/606/A125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deuterium fractionation has been used to study the thermal history of prestellar environments. Their formation pathways trace different regions of the disk and may shed light into the physical structure of the disk, including locations of important features for planetary formation. We aim to constrain the radial extent of the main deuterated species; we are particularly interested in spatially characterizing the high and low temperature pathways for enhancing deuteration of these species. We observed the disk surrounding the Herbig Ae star HD 163296 using ALMA in Band 6 and obtained resolved spectral imaging data of DCO^+^ (J=3-2), DCN (J=3-2) and N_2_D^+^ (J=3-2) with synthesized beam sizes of 0.53"x0.42", 0.53"x0.42", and 0.50"x0.39", respectively. We adopted a physical model of the disk from the literature and use the 3D radiative transfer code LIME to estimate an excitation temperature profile for our detected lines. We modeled the radial emission profiles of DCO^+^, DCN, and N_2_D^+^, assuming their emission is optically thin, using a parametric model of their abundances and our excitation temperature estimates.
- ID:
- ivo://CDS.VizieR/J/A+A/629/A75
- Title:
- HD 97048 H13CO+ and HC15N first detections
- Short Name:
- J/A+A/629/A75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of different molecular lines in protoplanetary disks provide valuable information on the gas kinematics, as well as constraints on the radial density and temperature structure of the gas. With ALMA we have detected H13CO+ (J=4-3) and HC15N (J=4-3) in the HD 97048 protoplanetary disk for the first time. We compare these new detections to the ringed continuum mm-dust emission and the spatially resolved CO (J=3-2) and HCO+ (J=4-3) emission. The radial distributions of the H^13^CO^+^ and HC^15^N emission show hints of ringed sub-structure whereas, the optically thick tracers, CO and HCO+, do not. We calculate the HCO^+^/H^13^CO^+^ intensity ratio across the disk and find that it is radially constant (within our uncertainties). We use a physio-chemical parametric disk structure of the HD 97048 disk with an analytical prescription for the HCO^+^ abundance distribution to generate synthetic observations of the HCO^+^ and H^13^CO^+^ disk emission assuming LTE. The best by-eye fit models require radial variations in the HCO^+^/H^13^CO^+^ abundance ratio and an overall enhancement in H^13^CO^+^ relative to HCO^+^. This highlights the need to consider isotope selective chemistry and in particular low temperature carbon isotope exchange reactions. This also points to the presence of a reservoir of cold molecular gas in the outer disk (T<10K, R>200au). Chemical models are required to confirm that isotope-selective chemistry alone can explain the observations presented here. With these data, we cannot rule out that the known dust substructure in the HD 97048 disk is responsible for the observed trends in molecular line emission, and higher spatial resolution observations are required to fully explore the potential of optically thin tracers to probe planet-carved dust gaps. We also report non-detections of H^13^CO^+^ and HC^15^N in the HD 100546 protoplanetary disk.
- ID:
- ivo://CDS.VizieR/J/ApJ/754/37
- Title:
- HD 192263 radial velocities and photometry
- Short Name:
- J/ApJ/754/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of the Transit Ephemeris Refinement and Monitoring Survey, we present new radial velocities and photometry of the HD 192263 system. Our analysis of the already available Keck-HIRES and CORALIE radial velocity measurements together with the five new Keck measurements we report in this paper results in improved orbital parameters for the system. We derive constraints on the size and phase location of the transit window for HD 192263b, a Jupiter-mass planet with a period of 24.3587+/-0.0022 days. We use 10 years of Automated Photoelectric Telescope photometry to analyze the stellar variability and search for planetary transits. We find continuing evidence of spot activity with periods near 23.4 days. The shape of the corresponding photometric variations changes over time, giving rise to not one but several Fourier peaks near this value. However, none of these frequencies coincides with the planet's orbital period and thus we find no evidence of star-planet interactions in the system. We attribute the ~23 day variability to stellar rotation. There are also indications of spot variations on longer (8 years) timescales. Finally, we use the photometric data to exclude transits for a planet with the predicted radius of 1.09R_J_, and as small as 0.79R_J_.
- ID:
- ivo://CDS.VizieR/J/AJ/158/189
- Title:
- HD 126516 radial velocity & photometric observations
- Short Name:
- J/AJ/158/189
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From numerous radial velocities as well as Johnson B and V differential photoelectric photometry, we have determined the orbital elements and other properties of the single-lined triple system HD 126516. This system consists of a narrow-lined F5 V star and an unseen M dwarf companion in a 2.1241 day circular orbit. The small, low-mass secondary produces detectable eclipses of the primary, and that pair has been given the variable star name V349 Vir. Variations of the center-of-mass velocity of this short-period system have an orbital period of 702.7 days or 1.92 yr and an eccentricity of 0.36. The third star is likely a K or M dwarf. From an analysis of our photometry, we conclude that the primary of HD 126516 is not a {gamma} Dor variable. Comparison with evolutionary tracks indicates that the primary is slightly metal-poor and has an age of 2.5 Gyr. The projected rotational velocity of the primary is very low, just 4 km/s, which is 10 times less than its synchronous rotational velocity. Thus, either that component's rotation is extremely non-synchronous or the inclinations of the rotational and orbital axes are very different, and so the primary has a very large spin-orbit misalignment. Because of the moderate age of the system and the fact that its orbit is already circularized, neither situation is expected theoretically.
- ID:
- ivo://CDS.VizieR/J/A+A/426/247
- Title:
- HD 173977 uby photometry and HRV
- Short Name:
- J/A+A/426/247
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectroscopic and photometric observations of the star HD 173977. It appears that the star is part of a double line binary system, with a period of 1.801d, corresponding to twice the period of the photometric variations. Hence the star is an ellipsoidal variable. The system is probably synchronized. The physical parameters of both components were derived through two independent methods, one based on evolutionary tracks, the other being the result of the behaviour of light curves in a close binary system. After removing the ellipsoidal variations, 3 frequencies are detected in the photometric data: 8.56, 14.51 and 16.42d^-1^, while 2 additional frequencies are also possible: 10.96 and 12.11d^-1^. In accordance with its position in the HR diagram, the primary component of HD 173977 should be considered as a delta Scuti star and no longer as a gamma Doradus star. In addition, HD 173844, used as a check star, is discovered variable with a 15.79d^-1^ frequency and is classified as a delta Scuti star.
- ID:
- ivo://CDS.VizieR/J/MNRAS/439/2078
- Title:
- High-frequency A-type pulsators
- Short Name:
- J/MNRAS/439/2078
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a survey using the WASP archive to search for high-frequency pulsations in F-, A- and B-type stars. Over 1.5 million targets have been searched for pulsations with amplitudes greater than 0.5 millimagnitude. We identify over 350 stars which pulsate with periods less than 30min. Spectroscopic follow-up of selected targets has enabled us to confirm 10 new rapidly oscillating Ap stars, 13 pulsating Am stars and the fastest known {delta} Scuti star. We also observe stars which show pulsations in both the high-frequency domain and the low-frequency {delta} Scuti range. This work shows the power of the WASP photometric survey to find variable stars with amplitudes well below the nominal photometric precision per observation.
- ID:
- ivo://CDS.VizieR/J/AJ/156/150
- Title:
- High-time-resolution photometry of AR Scorpii
- Short Name:
- J/AJ/156/150
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The unique binary AR Scorpii consists of an asynchronously rotating, magnetized white dwarf (WD) that interacts with its red-dwarf companion to produce a large-amplitude, highly coherent pulsation every 1.97 minutes. Over the course of two years, we obtained 39 hours of time-resolved, optical photometry of AR Sco at a typical cadence of 5 s to study this pulsation. We find that it undergoes significant changes across the binary orbital period and that its amplitude, phase, and waveform all vary as a function of orbital phase. We show that these variations can be explained by constructive and destructive interference between two periodic, double-peaked signals: the spin-orbit beat pulse, and a weaker WD spin pulse. Modeling of the light curve indicates that in the optical, the amplitude of the primary spin pulse is 50% of the primary beat amplitude, while the secondary maxima of the beat and spin pulses have similar amplitudes. Finally, we use our timings of the beat pulses to confirm the presence of the disputed spin-down of the WD. We measure a beat-frequency derivative of {nu}=(-5.14+/-0.32)x10^-17^ Hz/s and show that this is attributable to the spin-down of the WD. This value is approximately twice as large as the estimate from Marsh et al. but is nevertheless consistent with the constraints established in Potter & Buckley (2018MNRAS.478L..78P). Our precise measurement of the spin-down rate confirms that the decaying rotational energy of the magnetized WD is sufficient to power the excess electromagnetic radiation emitted by the binary.