Paul Robertson
A5053205401- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Space Exploration and Technology
- Planetary Science and Exploration
- Spectroscopy and Laser Applications
- Calibration and Measurement Techniques
- Atmospheric Ozone and Climate
- Astrophysical Phenomena and Observations
- History and Developments in Astronomy
- Scientific Research and Discoveries
- Methane Hydrates and Related Phenomena
- High-pressure geophysics and materials
- Geomagnetism and Paleomagnetism Studies
- Geophysics and Gravity Measurements
- Consumer Retail Behavior Studies
- Scientific Measurement and Uncertainty Evaluation
- Galaxies: Formation, Evolution, Phenomena
- Solar and Space Plasma Dynamics
- Spacecraft and Cryogenic Technologies
- Experimental and Theoretical Physics Studies
Fuller Theological Seminary
2025
University of California, Irvine
2018-2024
Dynamic Object Language Labs
2004-2024
California Institute of Technology
2023
The University of Sydney
2023
National Postdoctoral Association
2023
Astrobiology Center
2023
National Institutes of Natural Sciences
2023
Centre de Recerca Matemàtica
2023
NSF’s NOIRLab
2022
The M dwarf star Gliese 581 is believed to host four planets, including one (GJ 581d) near the habitable zone that could possibly support liquid water on its surface if it a rocky planet. detection of another habitable-zone planet--GJ 581g--is disputed, as significance depends eccentricity assumed for d. Analyzing stellar activity using Hα line, we measure rotation period 130 ± 2 days and correlation modulation with radial velocity. Correcting greatly diminishes signal GJ 581d (to 1.5...
A search of the time-series photometry from NASA's Kepler spacecraft reveals a transiting planet candidate orbiting 11th magnitude G5 dwarf KIC 10593626 with period 290 days. The characteristics host star are well constrained by high-resolution spectroscopy combined an asteroseismic analysis photometry, leading to estimated mass and radius 0.970 ± 0.060 M☉ 0.979 0.020 R☉. depth 492 10 ppm for three observed transits yields 2.38 0.13 Re planet. system passes battery tests false positives,...
The Second Workshop on Extreme Precision Radial Velocities defined circa 2015 the state of art Doppler precision and identified critical path challenges for reaching 10 cm s−1 measurement precision. presentations discussion key issues instrumentation data analysis workshop recommendations achieving this bold are summarized here. Beginning with High Accuracy Velocity Planet Searcher spectrograph, technological advances radial velocity (RV) measurements have focused building extremely stable...
We confirm 27 planets in 13 planetary systems by showing the existence of statistically significant anticorrelated transit timing variations, which demonstrates that planet candidates are same system, and long-term dynamical stability, places limits on masses – they planetary. All these newly confirmed have orbital periods place them near first-order mean motion resonances (MMRs), including six 2:1 MMR, five 3:2, one each 4:3, 5:4 6:5. In addition, several unconfirmed exist some (that cannot...
The Habitable-Zone Planet Finder is a stabilized, fiber-fed, NIR spectrograph being built for the 10m Hobby- Eberly telescope (HET) that will be capable of discovering low mass planets around M dwarfs. optical design HPF white pupil layout in vacuum cryostat cooled to 180 K. uses gold-coated mirrors, mosaic echelle grating, and single Teledyne Hawaii-2RG (H2RG) detector with 1.7-micron cutoff covering parts information rich z, Y J bands at spectral resolution R∼50,000. unique HET requires...
We have developed an optical design for a high resolution spectrograph in response to NASA's call extreme precision Doppler spectrometer (EPDS) the WIYN telescope. Our instrument covers wavelength range of 380 930 nm using single detector and with 100,000. To deliver most stable spectrum, we avoid use image slicer, favor large (195 mm diameter) beam footprint on 1x2 mosaic R4 Echelle grating. The is based classic white pupil layout, parabolic mirror that used as main transfer collimator....
Through the McDonald Observatory M Dwarf Planet Search, we have acquired nearly 3000 high-resolution spectra of 93 late-type (K5–M5) stars over more than a decade using High Resolution Spectrograph on Hobby–Eberly Telescope. This sample provides unique opportunity to investigate occurrence long-term stellar activity cycles for low-mass stars. In this paper, examine our targets as reflected in Hα feature. We identified periodic signals six stars, with periods ranging from days 10 years, and...
Abstract We demonstrate a path to hitherto unachievable differential photometric precisions from the ground, both in optical and near-infrared (NIR), using custom-fabricated beam-shaping diffusers produced specialized nanofabrication techniques. Such mold focal plane image of star into broad stable top-hat shape, minimizing errors due non-uniform pixel response, atmospheric seeing effects, imperfect guiding, telescope-induced variable aberrations seen defocusing. This PSF reshaping...
Insufficient instrument thermo-mechanical stability is one of the many roadblocks for achieving 10cm/s Doppler radial velocity (RV) precision, precision needed to detect Earth-twins orbiting Solar-type stars. Highly temperature and pressure stabilized spectrographs allow us better calibrate out instrumental drifts, thereby helping in distinguishing noise from astrophysical stellar signals. We present design performance Environmental Control System (ECS) Habitable-zone Planet Finder (HPF), a...
Abstract The warm Neptune GJ 3470b transits a nearby ( d = 29 pc) bright slowly rotating M1.5-dwarf star. Using spectroscopic observations during two with the newly commissioned NEID spectrometer on WIYN 3.5 m Telescope at Kitt Peak Observatory, we model classical Rossiter–McLaughlin effect, yielding sky-projected obliquity of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>λ</mml:mi> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>98</mml:mn>...
Convergent disk migration has long been suspected to be responsible for forming planetary systems with a chain of mean-motion resonances (MMR). Dynamical evolution over time could disrupt the delicate resonant configuration. We present TOI-1136, 700-Myr-old G star hosting at least 6 transiting planets between $\sim$2 and 5 $R_\oplus$. The orbital period ratios deviate from exact commensurability by only $10^{-4}$, smaller than $\sim$\,$10^{-2}$ deviations seen in typical Kepler near-resonant...
Abstract We present the discovery of TOI-5205b, a transiting Jovian planet orbiting solar metallicity M4V star, which was discovered using Transiting Exoplanet Survey Satellite photometry and then confirmed combination precise radial velocities, ground-based photometry, spectra, speckle imaging. TOI-5205b has one highest mass ratios for M-dwarf planets, with ratio almost 0.3%, as it orbits host star that is just 0.392 ± 0.015 M ⊙ . Its planetary radius 1.03 0.03 R J , while 1.08 0.06...
Abstract We confirm TOI-4201 b as a transiting Jovian-mass planet orbiting an early M dwarf discovered by the Transiting Exoplanet Survey Satellite. Using ground-based photometry and precise radial velocities from NEID Planet Finder Spectrograph, we measure mass of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>2.59</mml:mn> </mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.06</mml:mn> <mml:mo>+</mml:mo> <mml:mn>0.07</mml:mn>...
Abstract Recent discoveries of transiting giant exoplanets around M-dwarf stars (GEMS), aided by the all-sky coverage TESS, are starting to stretch theories planet formation through core-accretion scenario. upper limits on their occurrence suggest that they decrease with lower stellar masses, fewer GEMS lower-mass compared solar-type. In this paper, we discuss existing both confirmed planets, as well protoplanetary disk observations, and a combination tests reconcile these theoretical...
Abstract Gaia astrometry of nearby stars is precise enough to detect the tiny displacements induced by substellar companions, but radial velocity (RV) data are needed for definitive confirmation. Here we present RV follow-up observations 28 M and K with candidate astrometric which led confirmation two systems, Gaia-4b Gaia-5b, identification five systems that single lined require additional confirm as refutation 21 stellar binaries. a massive planet ( = 11.8 ± 0.7 J ) in P 571.3 1.4 day...
Gliese 667C is an M1.5V star with a multi-planet system, including planet candidates in the habitable zone. The exact number of planets system unclear, because existing radial velocity (RV) measurements are known to contain contributions from stellar magnetic activity. Following our analysis 581, we have analyzed effect activity on HARPS/HARPS-TERRA RVs GJ 667C, finding significant RV–activity correlation when using width (FWHM) HARPS cross-correlation function trace When correct for this...
We present a mass determination for the transiting super-Earth rho 1 Cancri e based on nearly 700 precise radial velocity (RV) measurements. This extensive RV data set consists of collected by McDonald Observatory planet search and published from Lick Keck observatories (Fischer et al. 2008). obtained 212 measurements with Tull Coude Spectrograph at Harlan J. Smith 2.7 m Telescope combined them new Doppler reduction 131 spectra that we have taken in 2003-2004 High-Resolution-Spectrograph...
Using solar spectral irradiance measurements from the SORCE spacecraft and F/F' technique, we have estimated radial velocity (RV) scatter induced on Sun by stellar activity as a function of wavelength. Our goal was to evaluate potential advantages using new near-infrared (NIR) spectrographs search for low-mass planets around bright F, G, K stars beating down effects. Unlike M dwarfs, which higher fluxes therefore greater RV information content in NIR, solar-type are brightest at visible...
We report constraints on the three-dimensional orbital architecture for all four planets known to orbit nearby M dwarf Gliese 876 based solely Doppler measurements and demanding long-term stability. Our dataset incorporates publicly available radial velocities taken with ELODIE CORALIE spectrographs, HARPS, Keck HIRES as well previously unpublished velocities. first quantitatively assess validity of thought GJ by computing Bayes factors a variety different coplanar models using an importance...
We validate the discovery of a 2 Earth radii sub-Neptune-size planet around nearby high proper motion M2.5-dwarf G 9-40 (EPIC 212048748), using high-precision near-infrared (NIR) radial velocity (RV) observations with Habitable-zone Planet Finder (HPF), precision diffuser-assisted ground-based photometry custom narrow-band photometric filter, and adaptive optics imaging. At distance $d=27.9\mathrm{pc}$, 9-40b is second closest transiting discovered by K2 to date. The planet's large transit...
Abstract LTT 1445 is a hierarchical triple M-dwarf star system located at distance of 6.86 pc. The primary 1445A (0.257 M ⊙ ) known to host the transiting planet 1445Ab with an orbital period 5.36 days, making it second-closest exoplanet system, and closest one for which dwarf. Using Transiting Exoplanet Survey Satellite data, we present discovery second in 3.12 days. We combine radial-velocity measurements obtained from five spectrographs, Echelle Spectrograph Rocky Exoplanets Stable...