- ID:
- ivo://CDS.VizieR/J/AJ/149/95
- Title:
- Photometry of nova LMC 2012
- Short Name:
- J/AJ/149/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an intensive multiwavelength campaign on nova LMC 2012. This nova evolved very rapidly in all observed wavelengths. The time to fall two magnitudes in the V band was only 2days. In X-rays the super soft phase began 13+/-5days after discovery and ended around day 50 after discovery. During the super soft phase, the Swift/XRT and Chandra spectra were consistent with the underlying white dwarf (WD) being very hot, ~1MK, and luminous, ~10^38^erg/s. The UV, optical, and near-IR photometry showed a periodic variation after the initial and rapid fading had ended. Timing analysis revealed a consistent 19.24+/-0.03hr period in all UV, optical, and near-IR bands with amplitudes of ~0.3mag which we associate with the orbital period of the central binary. No periods were detected in the corresponding X-ray data sets. A moderately high inclination system, i=60+/-10{deg}, was inferred from the early optical emission lines. The HST/STIS UV spectra were highly unusual with only the N v (1240{AA}) line present and superposed on a blue continuum. The lack of emission lines and the observed UV and optical continua from four epochs can be fit with a low mass ejection event, ~10^-6^M_{sun}_, from a hot and massive WD near the Chandrasekhar limit. The WD, in turn, significantly illuminated its subgiant companion which provided the bulk of the observed UV/optical continuum emission at the later dates. The inferred extreme WD characteristics and low mass ejection event favor nova LMC 2012 being a recurrent nova of the U Sco subclass.
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- ID:
- ivo://CDS.VizieR/J/AJ/162/203
- Title:
- Photometry of OGLE-2019-BLG-0304 with OGLE & KMTNet
- Short Name:
- J/AJ/162/203
- Date:
- 01 Feb 2022 07:08:03
- Publisher:
- CDS
- Description:
- We analyze the microlensing event OGLE-2019-BLG-0304, whose light curve exhibits two distinctive features: a deviation in the peak region and a second bump appearing ~61days after the main peak. Although a binary-lens model can explain the overall features, it leaves subtle but noticeable residuals in the peak region. We find that the residuals can be explained by the presence of either a planetary companion located close to the primary of the binary lens (3L1S model) or an additional close companion to the source (2L2S model). Although the 3L1S model is favored over the 2L2S model, with {Delta}{chi}2~8, securely resolving the degeneracy between the two models is difficult with the currently available photometric data. According to the 3L1S interpretation, the lens is a planetary system, in which a planet with a mass 0.51_-0.23_^+0.51^M_J_ is in an S-type orbit around a binary composed of stars with masses 0.27_-0.12_^+0.27^M{odot} and 0.10_-0.04_^+0.10^M{odot}. According to the 2L2S interpretation, however, the source is composed of G- and K-type giant stars and the lens is composed of a low-mass M dwarf and a brown dwarf with masses 0.12_-0.05_^+0.12^M{odot} and 0.045_-.019_^+0.045^M{odot}, respectively. The event illustrates the need for thorough model testing in the interpretation of lensing events with complex features in light curves.
- ID:
- ivo://CDS.VizieR/J/AJ/133/11
- Title:
- Photometry of OGLE-TR 111
- Short Name:
- J/AJ/133/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of our ongoing effort to measure exoplanet sizes and transit times with greater accuracy, we present I-band observations of two transits of OGLE-TR-111b.
- ID:
- ivo://CDS.VizieR/J/A+AS/106/339
- Title:
- Photometry of open cluster NGC 5606
- Short Name:
- J/A+AS/106/339
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/MNRAS/416/1077
- Title:
- Photometry of 3 open clusters
- Short Name:
- J/MNRAS/416/1077
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A comprehensive census of Galactic open cluster properties places unique constraints on the Galactic disc structure and evolution. In this framework, we investigate the evolutionary status of three poorly studied open clusters, Berkeley 31, Berkeley 23 and King 8, all located in the Galactic anticentre direction. To this aim, we make use of deep Large Binocular Telescope observations, reaching more than 6mag below the main-sequence turn-off. To determine the cluster parameters, namely age, metallicity, distance, reddening and binary fraction, we compare the observational colour--magnitude diagrams (CMDs) with a library of synthetic CMDs generated with different evolutionary sets (Padova, FRANEC and FST) and metallicities. We find that Berkeley 31 is relatively old, with an age between 2.3 and 2.9Gyr, and rather high above the Galactic plane, at about 700pc. Berkeley 23 and King 8 are younger, with best-fitting ages in the range 1.1-1.3 and 0.8-1.3 Gyr, respectively. The position above the Galactic plane is about 500-600 pc for the former and 200 pc for the latter. Although a spectroscopic confirmation is needed, our analysis suggests a subsolar metallicity for all three clusters. Based on observations collected at the Large Binocular Telescope (LBT) and in part at the Italian Telescopio Nazionale Galileo (TNG). The LBT is an international collaboration among institutions in the United States, Italy and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona University system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota and University of Virginia. The TNG is operated on the island of La Palma by the Fundacion Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.
- ID:
- ivo://CDS.VizieR/J/MNRAS/412/1265
- Title:
- Photometry of 3 open clusters
- Short Name:
- J/MNRAS/412/1265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To study the crucial range of Galactocentric distances between 12 and 16kpc, where little information is available, we have obtained VI CCD imaging of Berkeley 20 and BVI CCD imaging of Berkeley 66 and Tombaugh 2, three distant, old open clusters. Using the synthetic colour magnitude diagram (CMD) technique with three types of evolutionary tracks of different metallicities, we have determined age, distance, reddening and indicative metallicity of these systems. The CMD of Be 20 is best reproduced by stellar models with a metallicity about half of solar (Z=0.008 or 0.01), in perfect agreement with high resolution spectroscopic estimates. Its age is between 5 and 6Gyr from stellar models with overshooting and between 4.3 and 4.5Gyr from models without it. The distance modulus from the best fitting models is always (m-M)=14.7 (corresponding to a Galactocentric radius of about 16kpc), and the reddening E(B-V) ranges between 0.13 and 0.16. A slightly lower metallicity (Z=~0.006) appears to be more appropriate for Be 66. This cluster is younger (3Gyr), and closer, (m-M)=13.3 (i.e., at 12kpc from the Galactic centre), than Be 20, and suffers from high extinction, 1.2<=E(B-V)<=1.3, variable at the 2-3% level. Finally, the results for To 2 indicate that it is an intermediate age cluster, about 1.4Gyr or 1.6-1.8Gyr for models without and with overshooting, respectively. The metallicity is about half of solar (Z=0.006 to 0.01), in agreement with spectroscopic determinations. The distance modulus is (m-M)=14.5, implying a distance of about 14kpc from the Galactic centre; the reddening E(B-V) is 0.31-0.4, depending on the model and metallicity, with a preferred value around 0.34.
- ID:
- ivo://CDS.VizieR/II/25
- Title:
- Photometry of orange-red CaI triplet in Late-Type Stars
- Short Name:
- II/25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Calcium absorption lines were measured using narrow-band photometry on 296 high and low velocity G8-K5 stars of all luminosity classes. Because the blue-violet region of the stellar spectra is too crowded for narrow-band photometry, this investigation of abundance involved measurements of the orange-red CaI triplet 4(3)P-5(3)S, with wavelengths 6102.7, 6122.2 and 6162.2{AA}. "Calcium triplet ratio" is defined as "the measured light intensity ratios, comparison/central regions, calibrated in terms of a standard lamp as described in previous Cambridge papers". The catalog (table I of paper) includes HD number, (B-V) color index, Mg b ratio, H{alpha} ratio, Calcium triplet ratio, and a running number.
- ID:
- ivo://CDS.VizieR/J/ApJ/721/412
- Title:
- Photometry of polar CV* 1RXS J173006.4+033813
- Short Name:
- J/ApJ/721/412
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of 1RXS J173006.4+033813, a polar cataclysmic variable with a period of 120.21 minutes. The white dwarf primary has a magnetic field of B=42^+6^_-5_MG and the secondary is an M3 dwarf. The system shows highly symmetric double-peaked photometric modulation in the active state as well as in quiescence. These arise from a combination of cyclotron beaming and ellipsoidal modulation. The projected orbital velocity of the secondary is K_2_=390+/-4km/s. We place an upper limit of 830+/-65pc on the distance.
- ID:
- ivo://CDS.VizieR/J/AJ/157/226
- Title:
- Photometry of Proxima Centauri from 2006 to 2017
- Short Name:
- J/AJ/157/226
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a global network of small telescopes, we have obtained light curves of Proxima Centauri at 329 observation epochs from 2006 to 2017. The planet Proxima b discovered by Anglada-Escude et al. (2016Natur.536..437A) with an orbital period of 11.186 days has an a priori transit probability of ~1.5%; if it transits, the predicted transit depth is about 5 mmag. In Blank et al. (2018AJ....155..228B), we analyzed 96 of our light curves that overlapped with predicted transit ephemerides from previously published tentative transit detections and found no evidence in our data that would corroborate claims of transits with a period of 11.186 days. Here we broaden our analysis, using 262 high-quality light curves from our data set to search for any periodic transit-like events over a range of periods from 1 to 30 days. We also inject a series of simulated planet transits and find that our data are sufficiently sensitive to have detected transits of 5 mmag depth, with recoverability ranging from ~100% for an orbital period of 1 day to ~20% for an orbital period of 20 days for the parameter spaces tested. Specifically, at the 11.186-day period and 5 mmag transit depth, we rule out transits in our data with high confidence. We are able to rule out virtually all transits of other planets at periods shorter than 5 days and depths greater than 3 mmag; however, we cannot confidently rule out transits at the period of Proxima b due to incomplete orbital phase coverage and a lack of sensitivity to transits shallower than 4 mmag.
- ID:
- ivo://CDS.VizieR/J/AJ/155/12
- Title:
- Photometry of Proxima Centauri observed by BSST
- Short Name:
- J/AJ/155/12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Proxima Centauri is known as the closest star to the Sun. Recently, radial velocity (RV) observations revealed the existence of an Earth-mass planet around it. With an orbital period of ~11 days, Proxima Centauri b is probably in the habitable zone of its host star. We undertook a photometric monitoring campaign to search for its transit, using the Bright Star Survey Telescope at the Zhongshan Station in Antarctica. A transit-like signal appearing on 2016 September 8 has been tentatively identified. Its midtime, T_C_=2457640.1990+/-0.0017 HJD, is consistent with the predicted ephemeris based on the RV orbit in a 1{sigma} confidence interval. Time-correlated noise is pronounced in the light curve of Proxima Centauri, affecting the detection of transits. We develop a technique, in a Gaussian process framework, to gauge the statistical significance of a potential transit detection. The tentative transit signal reported here has a confidence level of 2.5{sigma}. Further detection of its periodic signals is necessary to confirm the planetary transit of Proxima Centauri b. We plan to monitor Proxima Centauri in the next polar night at Dome A in Antarctica, taking advantage of continuous darkness. Kipping et al. (2017, J/AJ/153/93) reported two tentative transit-like signals of Proxima Centauri b observed by the Microvariability and Oscillation of Stars space telescope in 2014 and 2015. The midtransit time of our detection is 138 minutes later than that predicted by their transit ephemeris. If all of the signals are real transits, the misalignment of the epochs plausibly suggests transit timing variations of Proxima Centauri b induced by an outer planet in this system.
