M. Hundertmark
A5014569920- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Astrophysical Phenomena and Observations
- History and Developments in Astronomy
- Galaxies: Formation, Evolution, Phenomena
- Calibration and Measurement Techniques
- Planetary Science and Exploration
- Remote Sensing in Agriculture
- Pulsars and Gravitational Waves Research
- Dark Matter and Cosmic Phenomena
- CCD and CMOS Imaging Sensors
- Advanced Vision and Imaging
- Spacecraft Design and Technology
- Atmospheric Ozone and Climate
- Scientific Measurement and Uncertainty Evaluation
- Impact of Light on Environment and Health
- Cosmology and Gravitation Theories
- Advanced Semiconductor Detectors and Materials
- Hydrocarbon exploration and reservoir analysis
- Advanced optical system design
Heidelberg University
2016-2025
University of St Andrews
2012-2019
University of Copenhagen
2014-2019
Max Planck Institute for Astronomy
2019
University of Göttingen
2008-2016
European Southern Observatory
2015
Natural History Museum Aarhus
2014-2015
Abstract We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). used Hubble Space Telescope (HST) to carry out precise astrometry source star long-duration ( t E ≃ 270 days), high-magnification microlensing event MOA-2011-BLG-191/OGLE-2011-BLG-0462 (hereafter designated as MOA-11-191/OGLE-11-462), in direction Galactic bulge. HST imaging, conducted at eight epochs over interval 6 yr, reveals a clear relativistic astrometric deflection...
We present the first microlensing candidate for a free-floating exoplanet–exomoon system, MOA-2011-BLG-262, with primary lens mass of Mhost ∼ 4 Jupiter masses hosting sub-Earth moon. The argument an exomoon hinges on system being relatively close to Sun. data constrain product MLπrel where ML is and πrel lens–source relative parallax. If nearby (large πrel), then small (a few masses) companion sub-Earth-mass exomoon. best-fit solution has large proper motion, μrel = 19.6 ± 1.6 mas yr−1,...
We present the analysis of first circumbinary planet microlensing event, OGLE-2007-BLG-349. This event has a strong planetary signal that is best fit with mass ratio $q \approx 3.4\times10^{-4}$, but there an additional due to lens mass, either another or star. find acceptable light curve fits two classes models: 2-planet models (with single host star) and models. The also reveals significant parallax effect, which constrains system be $M_L 0.7 M_\odot$. Hubble Space Telescope images resolve...
We present new ground-based, multi-colour, broad-band photometric measurements of the physical parameters, transmission and emission spectra transiting extrasolar planet WASP-19b. The are based on observations eight transits four occultations through a Gunn i filter using 1.54-m Danish Telescope, 14 an Rc at Perth Exoplanet Survey Telescope (PEST) observatory one transit observed simultaneously optical (Sloan g′, r′, i′, z′) three near-infrared (J, H, K) filters, Gamma Ray Burst Optical...
We report the detection of a Cold Neptune m_planet=21+/-2MEarth orbiting 0.38MSol M dwarf lying 2.5-3.3 kpc toward Galactic center as part campaign combining ground-based and Spitzer observations to measure distribution planets. This is first time that complex real-time protocols described by Yee et al. (2015), which aim maximize planet sensitivity while maintaining sample integrity, have been carried out in practice. Multiple survey follow-up teams successfully combined their efforts within...
Abstract Within less than 15 years, the count of known planets orbiting stars other Sun has risen from none to more 400 with detections arising four successfully applied techniques: Doppler‐wobbles, planetary transits, gravitational microlensing, and direct imaging. While hunt for twin Earths is on, a statistically well‐defined sample population in all their variety required probing models planet formation orbital evolution so that origin harbour life, like including ours, can be understood....
We present updates to \textsc{prism}, a photometric transit-starspot model, and \textsc{gemc}, hybrid optimisation code combining MCMC genetic algorithm. then high-precision photometry of four transits in the WASP-6 planetary system, two which contain starspot anomaly. All were modelled using \textsc{prism} physical properties system calculated. find mass radius host star be $0.836\pm 0.063\,{\rm M}_\odot$ $0.864\pm0.024\,{\rm R}_\odot$, respectively. For planet we $0.485\pm 0.027\,{\rm...
We present time-series photometric observations of thirteen transits in the planetary systems WASP-24, WASP-25 and WASP-26. All three have orbital obliquity measurements, WASP-24 WASP-26 been observed with Spitzer, was previously comparatively neglected. Our light curves were obtained using telescope-defocussing method scatters 0.5 to 1.2 mmag relative their best-fitting geometric models. used these data measure physical properties ephemerides high precision, finding that our improved...
We present a general framework for matching the point-spread function (PSF), photometric scaling and sky background between two images, subject which is commonly referred to as difference image analysis (DIA). introduce new concept of spatially varying scale factor will be important DIA applied wide-field imaging data in order adapt transparency airmass variations across field-of-view. Furthermore, we demonstrate how separately control degree spatial variation each kernel basis function,...
Observations of accretion disks around young brown dwarfs (BDs) have led to the speculation that they may form planetary systems similar normal stars. While there been several detections planetary-mass objects BDs (2MASS 1207-3932 and 2MASS 0441-2301), these companions relatively large mass ratios projected separations, suggesting formed in a manner analogous stellar binaries. We present discovery object orbiting field BD via gravitational microlensing, OGLE-2012-BLG-0358Lb. The system is...
Aims: We present 11 high-precision photometric transit observations of the transiting super-Earth planet GJ1214b. Combining these data with from other authors, we investigate ephemeris for possible signs timing variations (TTVs) using a Bayesian approach. Methods: The were obtained telescope-defocusing techniques, and achieve high precision random errors in photometry as low 1mmag per point. To possibility TTVs light curve, calculate overall probability TTV signal methods. Results: are used...
We report 13 high-precision light curves of eight transits the exoplanet WASP-52b, obtained by using four medium-class telescopes, through different filters, and adopting defocussing technique. One transit was recorded simultaneously from two observatories another one same site but with instruments, including a multi-band camera. Anomalies were clearly detected in five modelled as starspots occulted planet during events. fitted clean jktebop code, those anomalies prism+gemc codes order to...
We present photometric observations of four transits in the WASP-17 planetary system, obtained using telescope defocusing techniques and with scatters reaching 0.5 mmag per point. Our revised orbital period is 4.0 ± 0.6 s longer than previous measurements, a difference 6.6σ, does not support published detections eccentricity this system. model light curves jktebop code calculate physical properties system by recourse to five sets theoretical stellar predictions. The resulting radius, Rb =...
We present microlens parallax measurements for 21 (apparently) isolated lenses observed toward the Galactic bulge that were imaged simultaneously from Earth and Spitzer, which was ∼1 AU west of in projection. combine these with a kinematic model Galaxy to derive distance estimates each lens, error bars are small compared Sun's galactocentric distance. The ensemble therefore yields well-defined cumulative distribution lens distances. In principle, it is possible compare this against set...
WASP-80 is one of only two systems known to contain a hot Jupiter which transits its M-dwarf host star. We present eight light curves transit event, obtained simultaneously using defocussed telescopes. These data were taken through the Bessell I, Sloan griz and near-infrared JHK passbands. use our search for opacity-induced changes in planetary radius, but find that all values agree with each other. Our are therefore consistent flat transmission spectrum within observational uncertainties....
We present 17 transit light curves of the ultrashort period planetary system WASP-103, a strong candidate for detection tidally-induced orbital decay. use these to establish high-precision reference epoch timing studies. The time mid-point is now measured an accuracy 4.8 s, versus 67.4 s in discovery paper, aiding future searches With help published spectroscopic measurements and theoretical stellar models, we determine physical properties high precision detailed error budget calculations....
We report the discovery of a microlensing exoplanet OGLE-2012-BLG-0563Lb with planet–star mass ratio . Intensive photometric observations high-magnification event allow us to detect clear signal planet. Although no parallax is detected in light curve, we instead succeed at detecting flux from host star high-resolution JHK'-band images obtained by Subaru/AO188 and Infrared Camera Spectrograph instruments, allowing constrain absolute physical parameters planetary system. With help...
The computation of microlensing light curves represents a bottleneck for the modeling planetary events, making broad searches in vast parameter space extremely time-consuming. release first version VBBinaryLensing (based on advanced contour integration method presented Bozza(2010)) has represented considerable advance field, with birth several analysis platforms running this code. Here we present 2.0 VBBinaryLensing, which contains upgrades respect to version, including new decision trees...
We present high-precision photometry of five consecutive transits WASP-18, an extrasolar planetary system with one the shortest orbital periods known. Through use telescope defocusing we achieve a photometric precision 0.47–0.83 mmag per observation over complete transit events. The data are analyzed using jktebop code and three different sets stellar evolutionary models. find mass radius planet to be Mb = 10.43 ± 0.30 0.24 MJup Rb 1.165 0.055 0.014 RJup (statistical systematic errors),...
We present high-precision photometry of three transits the extrasolar planetary system WASP-2, obtained by defocussing telescope, and achieving point-to-point scatters between 0.42 0.73 mmag. These data are modelled using JKTEBOP code, taking into account light from recently-discovered faint star close to system. The physical properties WASP-2 derived tabulated predictions five different sets stellar evolutionary models, allowing both statistical systematic errorbars be specified. find mass...
Microlensing detections of cool planets are important for the construction an unbiased sample to estimate frequency beyond snow line, which is where giant thought form according core accretion theory planet formation. In this paper, we report discovery a detected from analysis light curve high-magnification microlensing event MOA 2010-BLG-477. The measured planet–star mass ratio q = (2.181 ± 0.004) × 10−3 and projected separation s 1.1228 0.0006 in units Einstein radius. angular radius...
Although many models have been proposed, the physical mechanisms responsible for formation of low-mass brown dwarfs are poorly understood. The multiplicity properties and minimum mass brown-dwarf function provide critical empirical diagnostics these mechanisms. We present discovery via gravitational microlensing two very low-mass, tight binary systems. These binaries directly precisely measured total system masses 0.025 Msun 0.034 Msun, projected separations 0.31 AU 0.19 AU, making them...
We report the gravitational microlensing discovery of a sub-Saturn mass planet, MOA-2009-BLG-319Lb, orbiting K or M-dwarf star in inner Galactic disk bulge. The high cadence observations MOA-II survey discovered this event and enabled its identification as magnification approximately 24 hours prior to peak magnification. As result, planetary signal at light curve was observed by 20 different telescopes, which is largest number telescopes contribute date. model for indicates planet-star ratio...
We present an analysis of the anomalous microlensing event, MOA-2010-BLG-073, announced by Microlensing Observations in Astrophysics survey on 2010 March 18. This event was remarkable because source previously known to be photometrically variable. Analyzing pre-event light curve, we demonstrate that it is irregular variable over timescales >200 days. Its dereddened color, (V − I)S, 0, 1.221 ± 0.051 mag, and from our lens model derive a radius 14.7 1.3 R☉, suggesting red giant star. initially...