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Studies1,2 have shown that the remnants of destroyed planets and debris-disk planetesimals can survive the volatile evolution of their host stars into white dwarfs3,4, but few intact planetary bodies around white dwarfs have been detected5–8. Simulations predict9–11 that planets in Jupiter-like orbits around stars of ≲8 M☉ (solar mass) avoid being destroyed by the strong tidal forces of their stellar host, but as yet, there has been no observational confirmation of such a survivor. Here we report the non-detection of a main-sequence lens star in the microlensing event MOA-2010-BLG-477Lb12 using near-infrared observations from the Keck Observatory. We determine that this system contains a 0.53 ± 0.11 M☉ white-dwarf host orbited by a 1.4 ± 0.3 Jupiter-mass planet with a separation on the plane of the sky of 2.8 ± 0.5 astronomical units, which implies a semi-major axis larger than this. This system is evidence that planets around white dwarfs can survive the giant and asymptotic giant phases of their host’s evolution, and supports the prediction that more than half of white dwarfs have Jovian planetary companions13. Located at approximately 2.0 kiloparsecs towards the centre of our Galaxy, it is likely to represent an analogue to the end stages of the Sun and Jupiter in our own Solar System.The authors show not only that planetary bodies around white dwarfs can survive but also that more than half of white dwarfs might have Jovian planetary companions. [ABSTRACT FROM AUTHOR]

We present the analysis of stellar binary microlensing event OGLE-2015-BLG-0060 based on observations obtained from 13 different telescopes. Intensive coverage of the anomalous parts of the light curve was achieved by automated follow-up observations from the robotic telescopes of the Las Cumbres Observatory. We show that, for the first time, all main features of an anomalous microlensing event are well covered by follow-up data, allowing us to estimate the physical parameters of the lens. The strong detection of second-order effects in the event light curve necessitates the inclusion of longer-baseline survey data in order to constrain the parallax vector. We find that the event was most likely caused by a stellar binary-lens with masses |$M_{\star 1} = 0.87 \pm 0.12 \, \mathrm{M}_{\odot }$| and |$M_{\star 2} = 0.77 \pm 0.11 \, \mathrm{M}_{\odot }$|⁠. The distance to the lensing system is 6.41 ± 0.14 kpc and the projected separation between the two components is 13.85 ± 0.16 au. Alternative interpretations are also considered. [ABSTRACT FROM AUTHOR]

Reactions of Ar+(2P3/2) ions with H2, N2, O2, and CO have been studied with the CRESU apparatus at 30 K in argon buffer gas and with the newly developed mass-selected ion injector (CRESUS configuration) at 20 and 70 K in helium buffer gas. The atom exchange reaction with H2 is rather fast, with a rate coefficient k showing a small energy dependence well represented by k=1.5×10-9E0.16 cm3 s-1 with the collision energy in the center-of-mass frame, E, in the range 2.5×10-3-0.65 eV. This result is more compatible with a frozen-rotor capture model rather than with a threshold model for endoergic reactions. Concerning the reaction with N2, a competition between the two exit channels involving the two first vibrational levels of the N+2 product ion explains the minimum of the rate constant suggested at about 140 K by previous SIFT experiments [D. Smith and N. G. Adams, Phys. Rev. A 23, 2327 (1981)] and presently confirmed. The rate coefficients for the charge transfer reactions with O2 and CO increase with decreasing energy, i.e., k=9.6×10-12E-0.51 and k=1.1×10-11E-0.47 cm3 s-1, respectively, for E in the range 2.5×10-3-0.3 eV. Both these reactions proceed via an intimate collision mechanism. [ABSTRACT FROM AUTHOR]

The reactions of N+(3P) ions with normal, para, and deuterated hydrogens have been examined at temperatures below 163 K by using the CRESU technique with both helium and nitrogen buffer gases. All these reactions have decreasing rate coefficients with decreasing temperature. Comparison of the data for normal and para-H2 reveals the drastic importance of rotational energy in promoting these processes. Analysis of these results shows a better agreement between the n-H2, p-H2, and HD data if the spin–orbit energy of N+(3P) is also considered as efficient as kinetic and rotational energies in driving the reactions. It follows that the endothermicity of the reaction N+(3P0) +H2(X 1Σ+g,J=0) →NH+(X 2Π,J=0) +H(2S) is (18±2) meV. This yields a proton affinity of N equal to (3.524±0.003) eV and a dissociation energy of NH of (3.42±0.01) eV. [ABSTRACT FROM AUTHOR]

In the gas phase O+2 reacts with methane at 300 K to produce a hydrogen atom and the CH3O+2 ion. The structure of this ion has recently been determined to be H2COOH+, methylene hydroperoxide ion. The reaction rate coefficients and product distributions have now been measured at 300 K for the CHnD4-n isotopes. The reaction shows both inter- and intramolecular isotope effects, e.g., CH2D2 reacts more slowly than methane and more rapidly than CD4, but loses hydrogen or deuterium with equal probability. The ion readily transfers HO+ to alkenes, CS2, and many other neutral molecules. The reaction with CS2 has been used to investigate the isotopic distribution within mixed isotope product ions. In addition, the reaction rate coefficients for both CH4 and CD4 have been measured as functions of temperature between 20 and 500 K; in both cases a clear minimum is observed in the reaction rate coefficient near room temperature. A mechanism for the reaction is proposed which allows us to model the temperature dependence of the reaction rate coefficient over the entire range for which there are data. [ABSTRACT FROM AUTHOR]

Despite their importance, very few RR Lyrae (RRL) stars have been known to reside in binary systems. We report on a search for binary RRL in the OGLE-III Galactic bulge data. Our approach consists in the search for evidence of the light-travel time effect in so-called observed minus calculated (O - C) diagrams. Analysis of 1952 well-observed fundamentalmode RRL in the OGLE-III data revealed an initial sample of 29 candidates. We used the recently released OGLE-IV data to extend the baselines up to 17 yr, leading to a final sample of 12 firm binary candidates. We provide O - C diagrams and binary parameters for this final sample, and also discuss the properties of eight additional candidate binaries whose parameters cannot be firmly determined at present. We also estimate that ≳ 4 per cent of the RRL reside in binary systems. [ABSTRACT FROM AUTHOR]

The Exoplanet Euclid Legacy Survey (ExELS) proposes to determine the frequency of cold exoplanets down to Earth mass from host separations of ∼1 au out to the free-floating regime by detecting microlensing events in Galactic bulge. We show that ExELS can also detect large numbers of hot, transiting exoplanets in the same population. The combined microlensing+transit survey would allow the first self-consistent estimate of the relative frequencies of hot and cold sub-stellar companions, reducing biases in comparing ‘near-field’ radial velocity and transiting exoplanets with ‘far-field’ microlensing exoplanets. The age of the bulge and its spread in metallicity further allows ExELS to better constrain both the variation of companion frequency with metallicity and statistically explore the strength of star–planet tides. We conservatively estimate that ExELS will detect ∼4100 sub-stellar objects, with sensitivity typically reaching down to Neptune-mass planets. Of these, ∼600 will be detectable in both Euclid's VIS (optical) channel and Near Infrared Spectrometer and Photometer (NISP)-H-band imager, with ∼90 per cent of detections being hot Jupiters. Likely scenarios predict a range of 2900–7000 for VIS and 400–1600 for H band. Twice as many can be expected in VIS if the cadence can be increased to match the 20-min H-band cadence. The separation of planets from brown dwarfs via Doppler boosting or ellipsoidal variability will be possible in a handful of cases. Radial velocity confirmation should be possible in some cases, using 30 m-class telescopes. We expect secondary eclipses, and reflection and emission from planets to be detectable in up to ∼100 systems in both VIS and NISP-H. Transits of ∼500 planetary-radius companions will be characterized with two-colour photometry and ∼40 with four-colour photometry (VIS,YJH), and the albedo of (and emission from) a large sample of hot Jupiters in the H band can be explored statistically. [ABSTRACT FROM AUTHOR]

We present a catalogue of 1768 eclipsing binary stars (EBs) detected in the Large Magellanic Cloud (LMC) by the second generation of the EROS survey (hereinafter EROS-2); 493 of them are new discoveries located in outer regions (out of the central bar) of the LMC. These sources were originally included in a list of candidate classical Cepheids (CCs) extracted from the EROS-2 catalogue on the basis of the period (0.89 < PEROS < 15.85 d) versus luminosity [13.39 < 〈BEROS〉 < 17.82 mag] diagram. After visual inspection of the light curves we reclassified them as eclipsing binaries. They have blue colours (BEROS − REROS < 0.2 mag) hence we classed them as hot eclipsing binaries (HEBs) containing hot massive components: main sequence (MS) stars or blue giants. We present Ks-band light curves for 999 binaries from our sample that have a counterpart in the VISTA near-infrared ESO public survey of the Magellanic Clouds system (VMC). We provide spectral classifications of 13 HEBs with existing spectroscopy. We divided our sample into contact-like binaries and detached/semi-detached systems based on both visual inspection and the parameters of the Fourier decomposition of the light curves and analysed the period–luminosity (PL) relations of the contact-like systems using the REROS and Ks magnitudes at maximum light. The contact-like binaries in our sample do not follow PL relations. We analysed the sample of contact binaries from the OGLE III catalogue and confirmed that PLI and ${\rm PL}_{K_{\rm s}}$ sequences are defined only by eclipsing binaries containing a red giant component. [ABSTRACT FROM PUBLISHER]

ABSTRACT We present a new classification method for quasar identification in the EROS-2 and MACHO data sets based on a boosted version of a random forest classifier. We use a set of variability features including parameters of a continuous autoregressive model. We prove that continuous autoregressive parameters are very important discriminators in the classification process. We create two training sets (one for EROS-2 and one for MACHO data sets) using known quasars found in the Large Magellanic Cloud (LMC). Our model's accuracy in both EROS-2 and MACHO training sets is about 90 per cent precision and 86 per cent recall, improving the state-of-the-art models, accuracy in quasar detection. We apply the model on the complete, including 28 million objects, EROS-2 and MACHO LMC data sets, finding 1160 and 2551 candidates, respectively. To further validate our list of candidates, we cross-matched our list with 663 previously known strong candidates, getting 74 per cent of matches for MACHO and 40 per cent in EROS. The main difference on matching level is because EROS-2 is a slightly shallower survey which translates to significantly lower signal-to-noise ratio light curves. [ABSTRACT FROM AUTHOR]

ABSTRACT The VISTA Magellanic Cloud (VMC; PI: M.-R. L. Cioni) survey is collecting deep Ks-band time series photometry of the pulsating variable stars hosted by the system formed by the two Magellanic Clouds (MCs) and the bridge connecting them. In this paper, we present the first results for classical Cepheids, from the VMC observations of two fields in the Large Magellanic Cloud (LMC), centred on the South Ecliptic Pole and the 30 Doradus star-forming regions, respectively. The VMC Ks-band light curves of the Cepheids are well sampled (12 epochs) and of excellent precision (typical errors of ∼0.01 mag). We were able to measure for the first time the Ks magnitude of the faintest classical Cepheids in the LMC ( Ks ∼ 17.5 mag), which are mostly pulsating in the first overtone (FO) mode, and to obtain FO period-luminosity ( PL), period-Wesenheit ( PW) and period-luminosity-colour ( PLC) relations, spanning the full period range from 0.25 to 6 d. Since the longest period Cepheid in our data set has a variability period of 23 d, we have complemented our sample with literature data for brighter F Cepheids. On this basis, we have built a PL relation in the Ks band that, for the first time, includes short-period - hence low-luminosity - pulsators, and spans the full range from 1.6 to 100 d in period.We also provide the first ever empirical PW and PLC relations using the ( V − Ks) colour and time series Ks photometry. The very small dispersion (∼0.07 mag) of these relations makes them very well suited to study the three-dimensional geometry of the Magellanic system. The use of 'direct' (parallax- and Baade-Wesselink-based) distance measurements to both Galactic and LMC Cepheids allowed us to calibrate the zero-points of the PL, PW and PLC relations obtained in this paper, and in turn to estimate an absolute distance modulus of ( m − M)0 = 18.46 ± 0.03 mag for the LMC. This result is in agreement with most of the latest literature determinations based on classical Cepheids. [ABSTRACT FROM AUTHOR]

We have started a survey of M 33 in order to find variable stars and Cepheids in particular. We have obtained more than 30 epochs of g'r'i' data with the CFHT and the one-square-degree camera MegaCam. We present first results from this survey, including the search for variable objects and a basic characterization of the various groups of variable stars. [ABSTRACT FROM AUTHOR]

We have conducted a variability survey of the Local Group galaxy M33, using g′, r′, and i′ observations from 27 nights spanning 17 months, made with the MegaPrime/MegaCam instrument on the 3.6-m Canada–France–Hawaii Telescope (CFHT). We identify more than 36 000 variable sources with g′, r′, i′≲ 24, out of approximately two million point sources in a 1-deg2 field of view. This increases the number of known variables in this galaxy by more than a factor of 20. In this paper, we provide a brief description of the data and a general overview of the variable star population which includes more than 1300 candidate variable blue and red supergiant stars, more than 2000 Cepheids, and more than 19 000 long-period variable asymptotic giant branch and red giant branch stars. [ABSTRACT FROM AUTHOR]

Axisymmetric contoured Laval nozzles have been calculated in order to obtain uniform supersonic flow. For nitrogen and oxygen gases the calculation uses only similarity techniques, but for helium, complete calculations of the isentropic core and the boundary layer were performed for two sets of boundary conditions. Experimental testing has shown that the nitrogen or oxygen flows exhibit a good uniformity but that the helium flow was uniform only for one set of boundary conditions. The purpose of this work is to provide flow reactors for studies of ion-molecule reactions in the real temperature range of interstellar clouds (T<80 °K). [ABSTRACT FROM AUTHOR]

We started a systematic search for periodic variable-star candidates in the EROS-2 database in the context of preparatory work for the Gaia satellite mission. The goal is to evaluate different classification tools and strategies, and to identify a large sample of variable candidates. In this paper we present the results of an assessment study of a three-step identification and classification process. In the study we took a sample of about 80,000 stars from one of the LMC EROS fields. [ABSTRACT FROM PUBLISHER]

More than 10 years of microlensing survey observations by the EROS Collaboration have monitored several million stars, amongst them several thousand eclipsing binary stars. In this poster we present some of the difficulties and rewards of the study of this immense database. [ABSTRACT FROM AUTHOR]

Microlensing detections of cool planets are important for the construction of an unbiased sample to estimate the frequency of planets beyond the snow line, which is where giant planets are thought to form according to the core accretion theory of planet formation. In this paper, we report the discovery of a giant planet detected from the analysis of the light curve of a high-magnification microlensing event MOA 2010-BLG-477. The measured planet-star mass ratio is q = (2.181 ± 0.004) × 10–3 and the projected separation is s = 1.1228 ± 0.0006 in units of the Einstein radius. The angular Einstein radius is unusually large θE = 1.38 ± 0.11 mas. Combining this measurement with constraints on the “microlens parallax” and the lens flux, we can only limit the host mass to the range 0.13 < M/M☼ < 1.0. In this particular case, the strong degeneracy between microlensing parallax and planet orbital motion prevents us from measuring more accurate host and planet masses. However, we find that adding Bayesian priors from two effects (Galactic model and Keplerian orbit) each independently favors the upper end of this mass range, yielding star and planet masses of M* = 0.67+0.33– 0.13M☼ and mp = 1.5+0.8– 0.3MJUP at a distance of D = 2.3 ± 0.6 kpc, and with a semi-major axis of a = 2+3– 1 AU. Finally, we show that the lens mass can be determined from future high-resolution near-IR adaptive optics observations independently from two effects, photometric and astrometric. [ABSTRACT FROM AUTHOR]