T. Natusch
A5052196425- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Astro and Planetary Science
- GNSS positioning and interference
- Geophysics and Gravity Measurements
- Astronomical Observations and Instrumentation
- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Adaptive optics and wavefront sensing
- Pulsars and Gravitational Waves Research
- Atmospheric Ozone and Climate
- Solar and Space Plasma Dynamics
- Isotope Analysis in Ecology
- History and Developments in Astronomy
- Particle Accelerators and Free-Electron Lasers
- Planetary Science and Exploration
- Neutrino Physics Research
- Nuclear Physics and Applications
- Historical Astronomy and Related Studies
- Ionosphere and magnetosphere dynamics
- Methane Hydrates and Related Phenomena
Carter Observatory
2014-2024
Auckland University of Technology
2013-2024
University of Auckland
2009-2016
Possum Observatory
2014
The Ohio State University
2008
University of Notre Dame
2008
University of Warsaw
2008
Tel Aviv University
2008
Searches for extrasolar planets have uncovered an astonishing diversity of planetary systems, yet the frequency solar system analogs remains unknown. The gravitational microlensing planet search method is potentially sensitive to multiple-planet systems containing all except Mercury. We report detection a with microlensing. identify two masses ∼0.71 and ∼0.27 times mass Jupiter orbital separations ∼2.3 ∼4.6 astronomical units orbiting primary star ∼0.50 at distance ∼1.5 kiloparsecs. This...
We present the first measurement of planet frequency beyond "snow line," for planet-to-star mass-ratio interval −4.5 < log q −2, corresponding to range ice giants gas giants. find at mean mass ratio = 5 × 10−4 with no discernible deviation from a flat (Öpik's law) distribution in log-projected separation s. The determination is based on sample six planets detected intensive follow-up observations high-magnification (A>200) microlensing events during 2005–2008. sampled host stars have typical...
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 discovery of a Neptune-mass planet OGLE-2007-BLG-368Lb with planet–star mass ratio q = [9.5 ± 2.1] × 10−5 via gravitational microlensing. The planetary deviation was detected in real-time thanks to high cadence Microlensing Observations Astrophysics survey, light-curve monitoring and intensive follow-up observations. A Bayesian analysis returns stellar distance at Ml 0.64+0.21−0.26 M☉ Dl 5.9+0.9−1.4 kpc, respectively, so separation are Mp 20+7−8 M⊕ 3.3+1.4−0.8 AU,...
We report the detection of cool, Jovian-mass planet MOA-2007-BLG-400Lb. The was detected in a high-magnification microlensing event (with peak magnification A_max = 628) which primary lens transited source, resulting dramatic smoothing event. angular extent region perturbation due to is significantly smaller than size and as result planetary signature also smoothed out by finite source size. Thus deviation from single-lens fit broad relatively weak (~ few percent). Nevertheless, we...
Aims. We report the discovery of a planet with high planet-to-star mass ratio in microlensing event MOA-2009-BLG-387, which exhibited pronounced deviations over 12-day interval, one longest for any planetary event. The host is an M dwarf, range 0.07 M⊙ < Mhost 0.49 at 90% confidence. planet-star q = 0.0132 ± 0.003 has been measured extremely well, so best-estimated mass, mp 2.6 Jupiter masses median 0.19 M⊙.
Parallax is the most fundamental technique for measuring distances to astronomical objects. Although terrestrial parallax was pioneered over 2000 years ago by Hipparchus (ca. 140 B.C.E.) measure distance Moon, baseline of Earth so small that can generally only be applied objects in Solar System. However, there exists a class extreme gravitational microlensing events which effects readily detected and permit measurement distance, mass, transverse velocity lens. Here we report observations...
We present the discovery and mass measurement of cold, low-mass planet MOA-2009-BLG-266Lb, performed with gravitational microlensing method. This has a mp = 10.4 ± 1.7 M⊕ orbits star M⋆ 0.56 0.09 M☉ at semimajor axis AU an orbital period yrs. The host measurements are enabled by parallax effect, which is seen primarily in light curve distortion due to motion Earth. But analysis also demonstrates capability measure Deep Impact (or EPOXI) spacecraft heliocentric orbit. distance similar...
Impolite planet ignores host's partner Many known exoplanets (planets outside our own solar system) are hosted by binary systems that contain two stars. These planets normally circle around both of their Using microlensing data taken with a worldwide network telescopes, Gould et al. found twice the mass Earth circles just one pair The same approach has potential to uncover other similar star and help illuminate some mysteries formation. Science , this issue p. 46
We use Very Long Baseline Interferometry to measure the proper motions of three black hole X-ray binaries (BHXBs). Using these results together with data from literature and Gaia-DR2 collate best available constraints on motion, parallax, distance systemic radial velocity 16 BHXBs, we determined their dimensional Galactocentric orbits. extended this analysis estimate probability distribution for potential kick (PKV) a BHXB system could have received formation. Constraining kicks imparted...
We present a new analysis of the Jupiter+Saturn analog system, OGLE-2006-BLG-109Lb,c, which was first double planet system discovered with gravitational microlensing method. This is only multi-planet by any method measured masses for star and both planets. In addition to signatures two planets, this event also exhibits parallax signature finite source effects that provide direct measure expected brightness host confirmed Keck AO imaging, yielding M_* = 0.51(+0.05-0.04) M_sun, M_b 231+-19...
We report the discovery of a planetary system from observation high-magnification microlensing event OGLE-2012-BLG-0026. The lensing light curve exhibits complex central perturbation with multiple features. find that was produced by two planets located near Einstein ring planet host star. identify four possible solutions resulting well-known close/wide degeneracy. By measuring both lens parallax and radius, we estimate physical parameters system. According to best-fit model, masses are ∼0.11...
We report the detection of sub-Saturn-mass planet MOA-2008-BLG-310Lb and argue that it is strongest candidate yet for a bulge planet. Deviations from single-lens fit are smoothed out by finite-source effects so not immediately apparent light curve. Nevertheless, we find model in which primary has planetary companion favored over \Delta\chi^2 ~ 880 an additional three degrees freedom. Detailed analysis yields planet/star mass ratio q=(3.3+/-0.3)x10^{-4} angular separation between star within...
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...
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...
We employ VLTI GRAVITY to resolve, for the first time, two images generated by a gravitational microlens. The measurements of image separation \theta_{-,+}=3.78 +/- 0.05 mas, and hence Einstein radius \theta_E =1.87 0.03 are precise. This demonstrates robustness method, provided that source is bright enough (K <~ 10.5) order or larger than fringe spacing. When combined with measurement "microlens parallax" \pi_E, will together yield lens mass lens-source relative parallax proper motion....
Pluto occultations are historically rare events, having been observed in 1988, 2002, 2006, and, as moves into the crowded Galactic plane, on several occasions 2007. Here we present six results from our observations of 2006 June 12 event sites Australia and New Zealand. First, show that Pluto's bulk atmospheric column abundance, is over twice value measured implying nitrogen frost surface 1.2-1.7 K warmer than 1988 despite a 9% drop incident solar flux. We measure half-light shadow radius...
ABSTRACT We analyze the extreme high-magnification microlensing event OGLE-2008-BLG-279, which peaked at a maximum magnification of A ∼ 1600 on 2008 May 30. The peak this exhibits both finite-source effects and terrestrial parallax, from we determine mass lens, M l = 0.64 ± 0.10 ☉ , its distance, D 4.0 0.6 kpc. rule out Jupiter-mass planetary companions to lens star for projected separations in range 0.5–20 AU. More generally, find that was sensitive planets with masses as small <?CDATA $0.2...
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...
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...
Abstract We report the analysis of OGLE-2019-BLG-0960, which contains smallest mass-ratio microlensing planet found to date ( q = 1.2–1.6 × 10 −5 at 1 σ ). Although there is substantial uncertainty in satellite parallax measured by Spitzer, measurement annual effect combined with finite source allows us determine mass host star M L 0.3–0.6 ⊙ ), its m p 1.4–3.1 ⊕ projected separation between and a ⊥ 1.2–2.3 au), distance lens system D 0.6–1.2 kpc). The plausibly blend, could be checked...
We report the discovery of a Jupiter-mass planet orbiting an M-dwarf star that gave rise to microlensing event OGLE-2011-BLG-0265. Such system is very rare among known planetary systems and thus important for theoretical studies formation evolution. High-cadence temporal coverage signal combined with extended observations throughout allows us accurately model observed light curve. The final solution remains, however, degenerate yielding two possible configurations host star. In case...
We analyze the planetary microlensing event MOA-2010-BLG-328. The best fit yields host and masses of Mh = 0.11+/-0.01 M_{sun} Mp 9.2+/-2.2M_Earth, corresponding to a very late M dwarf sub-Neptune-mass planet, respectively. system lies at DL 0.81 +/- 0.10 kpc with projected separation r 0.92 0.16 AU. Because host's a-priori-unlikely close distance, as well unusual nature system, we consider possibility that microlens parallax signal, which determines mass is actually due xallarap (source...
We present a detailed analysis of survey and follow-up observations microlensing event OGLE-2012-BLG-0406 based on data obtained from 10 different observatories. Intensive coverage the lightcurve, especially perturbation part, allowed us to accurately measure parallax effect lens orbital motion. Combining our measurement with angular Einstein radius determined finite-source effects, we estimate physical parameters system. find that was caused by $2.73\pm 0.43\ M_{\rm J}$ planet orbiting...