- ID:
- ivo://CDS.VizieR/J/AJ/154/241
- Title:
- Photometry of a Kuiper Belt object: 2002 CC_249_
- Short Name:
- J/AJ/154/241
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Images of the Kuiper Belt object (126719) 2002 CC_249_ obtained in 2016 and 2017 using the 6.5 m Magellan-Baade Telescope and the 4.3 m Discovery Channel Telescope are presented. A light curve with a periodicity of 11.87+/-0.01 hr and a peak-to-peak amplitude of 0.79+/-0.04 mag is reported. This high amplitude double-peaked light curve can be due to a single elongated body, but it is best explained by a contact binary system from its U-/V-shaped light curve. We present a simple full-width-at-half-maximum test that can be used to determine if an object is likely a contact binary or an elongated object based on its light curve. Considering that 2002 CC_249_ is in hydrostatic equilibrium, a system with a mass ratio q_min_=0.6, and a density {rho}_min_=1 g/cm^3^, or less plausible a system with q_max_=1, and {rho}_max_=5 g/cm^3^ can interpret the light curve. Assuming a single Jacobi ellipsoid in hydrostatic equilibrium and an equatorial view, we estimate {rho}>=0.34 g/cm^3^, and a/b=2.07. Finally, we report a new color study showing that 2002 CC_249_ displays an ultra red surface characteristic of a dynamically Cold Classical trans-Neptunian object.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/483/209
- Title:
- Photometry of a stellar cluster near IRAS 07141-092
- Short Name:
- J/A+A/483/209
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-resolution optical UBVRI and H{alpha} images obtained with ALFOSC mounted on the Nordic Optical Telescope (NOT), near-infrared JHK_S_ images obtained with NOTCam at the Nordic Optical Telescope, and VLT/ISAAC images obtained through the H_2_ (2.12{mu}m) filter were all used to make photometric and morphological studies of the point sources and the nebula seen towards Sh2-294. Identification of PMS members was done using three different methods: comparison with isochrones in optical colour-magnitude diagrams and detection of either near-IR excess or H{alpha} emission.
- ID:
- ivo://CDS.VizieR/J/AJ/156/12
- Title:
- Photometry of {beta} Lyrae by the BRITE satellites
- Short Name:
- J/AJ/156/12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric instabilities of {beta} Lyrae ({beta} Lyr) were observed in 2016 by two red-filter BRITE satellites over more than 10 revolutions of the binary, with ~100 minute sampling. Analysis of the time series shows that flares or fading events take place typically three to five times per binary orbit. The amplitudes of the disturbances (relative to the mean light curve, in units of the maximum out-of-eclipse light flux, f.u.) are characterized by a Gaussian distribution with {sigma}=0.0130+/-0.0004 f.u. Most of the disturbances appear to be random, with a tendency to remain for one or a few orbital revolutions, sometimes changing from brightening to fading or the reverse. Phases just preceding the center of the deeper eclipse showed the most scatter while phases around the secondary eclipse were the quietest. This implies that the invisible companion is the most likely source of the instabilities. Wavelet transform analysis showed the domination of the variability scales at phase intervals 0.05-0.3 (0.65-4 days), with the shorter (longer) scales dominating in numbers (variability power) in this range. The series can be well described as a stochastic Gaussian process with the signal at short timescales showing a slightly stronger correlation than red noise. The signal decorrelation timescale, {tau}=(0.068+/-0.018) in phase or (0.88+/-0.23) days, appears to follow the same dependence on the accretor mass as that observed for active galactic nucleus and quasi-stellar object masses five to nine orders of magnitude larger than the {beta} Lyr torus-hidden component.
- ID:
- ivo://CDS.VizieR/J/AJ/158/148
- Title:
- Photometry of beta Lyr by the BRITE satellites.II
- Short Name:
- J/AJ/158/148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of {beta} Lyr in four months of 2018 by three BRIght Target Explorer (BRITE) Constellation satellites, the red-filter BRITE-Toronto and BRITE-Heweliusz, and the blue-filter BRITE-Lem, permitted a first, limited look into the light-curve variability in two spectral bands. The variations were found to be well correlated outside the innermost phases of the primary eclipses with the blue variations appearing to have smaller amplitudes than the red; this reduction may reflect their presumed origin in the cooler, outer parts of the accretion disk. This result must be confirmed with more extensive material as the current conclusions are based on observations spanning slightly less than three orbital cycles of the binary. The assumption of an instrumental problem and the applied corrections made to explain the unexpectedly large amplitude of the red-filter light curve observed with the BRITE-Toronto satellite in 2016 are fully confirmed by the 2018 results.
- ID:
- ivo://CDS.VizieR/J/A+A/496/453
- Title:
- Photometry of candidate members of NGC6611
- Short Name:
- J/A+A/496/453
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the list of candidate members of the young open cluster NGC 6611, selected in a field of view of 33'x34' by the X-rays emission and excesses in infrared bands. X-ray sources without infrared excesses are classified as candidate Class III cluster members; stars with infrared excesses as disk bearing members.
- ID:
- ivo://CDS.VizieR/J/ApJS/117/135
- Title:
- Photometry of Cepheids in Magellanic Clouds
- Short Name:
- J/ApJS/117/135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report BV(RI)C data for a select group of 14 Cepheids in the Large Magellanic Cloud and eight in the Small Magellanic Cloud that have preexisting radial velocity curves. The photometry was obtained as part of a program to determine distances to these Cepheids by means of the visual surface brightness technique and to improve significantly the optical BV(RI)C light curves of Magellanic Cloud Cepheids. The data were acquired on the 0.9 m telescope at Cerro Tololo Inter-American Observatory with the CFCCD instrument and with the 1 m photometric telescope at ESO using aperture photometry. The median number of measures per Cepheid is 46 in each band, and the uncertainty in the photometry is typically 0.01 mag. Using these data together with data from the literature, we determined improved periods for all variables. For most of the Cepheids, these revised periods lead to excellent, low-noise light curves, but for a few variables, the periods are obviously variable.
- ID:
- ivo://CDS.VizieR/J/A+AS/128/245
- Title:
- Photometry of chemically peculiar stars
- Short Name:
- J/A+AS/128/245
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Differential Stroemgren uvby photometric observations from the Four College Automated Photoelectric Telescope are presented for four Chemically Peculiar stars of the upper main sequence: the HgMn star binary AR Aurigae and the magnetic stars 3 Hydrae, 49 Cancri, and BX Bootis. AR Aurigae shows little variability except during the primary and secondary eclipses. The 11.305 day period of Maitzen et al. for 3 Hya is confirmed. A new period of 7.0501 days is found for 49 Cancri while a slightly refined period of 2.88756 days is derived for BX Boo.
- ID:
- ivo://CDS.VizieR/J/PASP/109/9
- Title:
- Photometry of chemically peculiar stars
- Short Name:
- J/PASP/109/9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Differential Stromgren uvby photometric observations from the Four College Automated Photoelectric Telescope of four magnetic Chemically Peculiar stars are used to refine rotational periods and to define the shapes of the light curves. HR 1643 (P=2.73475d) shows large phase variability in all four magnitudes. Theta Aur (P=3.6188d) exhibits large amplitude variations with two components contributing to the minima. For 49 Cam (P=4.28679d), we probably are observing both polar regions and much of the surface. The values for HR 3724 (P=33.984d) confirm Wolff's result that the main variability is in v.
2799. Photometry of CU Vir
- ID:
- ivo://CDS.VizieR/J/A+A/625/A34
- Title:
- Photometry of CU Vir
- Short Name:
- J/A+A/625/A34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CU Vir has been the first main sequence star that showed regular radio pulses that persist for decades, resembling the radio lighthouse of pulsars and interpreted as auroral radio emission similar to that found in planets. The star belongs to a rare group of magnetic chemically peculiar stars with variable rotational period. We study the ultraviolet (UV) spectrum of CU Vir obtained using STIS spectrograph onboard the Hubble Space Telescope (HST) to search for the source of radio emission and to test the model of the rotational period evolution. We used our own far-UV and visual photometric observations supplemented with the archival data to improve the parameters of the quasisinusoidal long-term variations of the rotational period. We predict the flux variations of CU Vir from surface abundance maps and compare these variations with UV flux distribution. We searched for wind, auroral, and interstellar lines in the spectra. The UV and visual light curves display the same long-term period variations supporting their common origin. New updated abundance maps provide better agreement with the observed flux distribution. The upper limit of the wind mass-loss rate is about 10^-12^M_{sun}_/yr. We do not find any auroral lines. We find rotationally modulated variability of interstellar lines, which is most likely of instrumental origin. Our analysis supports the flux redistribution from far-UV to near-UV and visual domains originating in surface abundance spots as the main cause of the flux variability in chemically peculiar stars. Therefore, UV and optical variations are related and the structures leading to these variations are rigidly confined to the stellar surface. The radio emission of CU Vir is most likely powered by a very weak presumably purely metallic wind, which leaves no imprint in spectra.
- ID:
- ivo://CDS.VizieR/J/A+A/588/A63
- Title:
- Photometry of DBS 77-78-102-160-161 regions
- Short Name:
- J/A+A/588/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report a study of the global properties of some embedded clusters placed in the fourth quadrant of the MilkyWay to clarify some issues related with their location into de Galaxy and their stellar formation processes. We performed BVI photometric observations in the region of DBS 77, 78, 102, 160, and 161 clusters and infrared spectroscopy in DBS 77 region. They were complemented with JHK data from VVV survey combined with 2MASS catalogue, and used mid-infrared information from GLIMPSE catalogue. We also searched for HI data from SGPS and PMN radio surveys, and previous spectroscopic stellar classification. The spectroscopic and photometric information allowed us to estimate the spectral classification of the brightest stars of each studied region. On the other hand, we used the radio data to investigate the interstellar material parameters and the continuum sources probably associated with the respective stellar components. We estimated the basic physical parameters of the clusters (reddening, distance, age, and initial mass function). We searched for HII regions located near to the studied clusters and we analyzed the possible link between them. In the particular case of DBS 160-161 clusters, we identified the HI bubble B332.5-0.1-42 located around them. We found that the mechanical energy injected to the interstellar medium by the more massive stars of this couple of clusters was enough to generate the bubble.
