Dakotah Tyler
A5031045240- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Scientific Research and Discoveries
- Planetary Science and Exploration
- Molecular Spectroscopy and Structure
- Quantum, superfluid, helium dynamics
- Middle East and Rwanda Conflicts
- Astrophysics and Cosmic Phenomena
- High-pressure geophysics and materials
- Nuclear Physics and Applications
- Spacecraft and Cryogenic Technologies
- Space Exploration and Technology
- Spacecraft Design and Technology
- Neutrino Physics Research
- Solar and Space Plasma Dynamics
- Space Satellite Systems and Control
- Astronomical Observations and Instrumentation
- History and Developments in Astronomy
- Geophysics and Gravity Measurements
University of California, Los Angeles
2022-2024
UCLA Health
2022
University of Cincinnati
2018
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 Studying the escaping atmospheres of highly irradiated exoplanets is critical for understanding physical mechanisms that shape demographics close-in planets. A number planetary outflows have been observed as excess H/He absorption during/after transit. Such an outflow has WASP-69b by multiple groups disagree on geometry and velocity structure outflow. Here, we report detection this planet’s using Keck/NIRSPEC first time. We 1.28 hr after egress until target set, demonstrating...
Abstract Despite the importance of Jupiter and Saturn to Earth’s formation habitability, there has not yet been a comprehensive observational study how giant exoplanets correlate with architectural properties close-in, sub-Neptune-sized exoplanets. This is largely because transit surveys are particularly insensitive planets at orbital separations ≳1 au, so their census Jupiter-like incomplete, inhibiting our relationship between small that do transit. To investigate distant, planets, we...
The evolutionary history of an extrasolar system is, in part, fossilized through its planets' orbital orientations relative to the host star's spin axis. However, spin-orbit constraints for warm Jupiters -- particularly binary star systems, which are amenable a wide range dynamical processes relatively scarce. We report measurement Rossiter-McLaughlin effect, observed with Keck/HIRES spectrograph, across transit Qatar-6 A b: Jupiter orbiting one within system. From this measurement, we...
Abstract We present a radial velocity (RV) analysis of TOI-1136, bright Transiting Exoplanet Survey Satellite (TESS) system with six confirmed transiting planets, and seventh single-transiting planet candidate. All planets in the are amenable to transmission spectroscopy, making TOI-1136 one best targets for intra-system comparison exoplanet atmospheres. is young (∼700 Myr), exhibits transit timing variations (TTVs). The youth contributes high stellar variability on order 50 m s −1 , much...
Abstract The Transiting Exoplanet Survey Satellite (TESS) has discovered hundreds of new worlds, with TESS planet candidates now outnumbering the total number confirmed planets from Kepler. Owing to differences in survey design, continues provide that are better suited for subsequent follow-up studies, including mass measurement through radial velocity (RV) observations, compared Kepler targets. In this work, we present TESS-Keck Survey’s (TKS) Mass Catalog: a uniform analysis all TKS RV...
Abstract The extreme environments of ultra-short-period planets (USPs) make excellent laboratories to study how exoplanets obtain, lose, retain, and/or regain gaseous atmospheres. We present the confirmation and characterization USP TOI-1347 b, a 1.8 ± 0.1 R ⊕ planet on 0.85 day orbit that was detected with photometry from TESS mission. measured radial velocities system using Keck/HIRES HARPS-N found be unusually massive at 11.1 1.2 M . mass radius b imply an Earth-like bulk composition. A...
We report the discovery of TOI-2180 b, a 2.8 $M_{\rm J}$ giant planet orbiting slightly evolved G5 host star. This transited only once in Cycle 2 primary Transiting Exoplanet Survey Satellite (TESS) mission. Citizen scientists identified 24 hr single-transit event shortly after data were released, allowing Doppler monitoring campaign with Automated Planet Finder telescope at Lick Observatory to begin promptly. The radial velocity observations refined orbital period b be 260.8$\pm$0.6 days,...
Abstract We present an analysis of 126 new radial velocity measurements from the MAROON-X spectrograph to investigate TOI-1266 system, which hosts two known transiting sub-Neptunes at 10.8 and 18.8 days. integrated our with existing HARPS-N for this system derived revised masses b c M = 4.09 ± 0.45 ⊕ 2.64 0.52 , respectively. The Keplerian fit combined datasets enabled ≈35% ≈41% improvement in mass precision planet c, respectively, compared previously published values. With bulk densities ρ...
We report the masses, sizes, and orbital properties of 86 planets orbiting 55 stars observed by NASA's K2 Mission with follow-up Doppler measurements HIRES spectrometer at W. M. Keck Observatory Automated Planet Finder Lick Observatory. Eighty-one were discovered from their transits in photometry, while five found based on subsequent transiting planet host stars. The sizes range Earth-size to larger than Jupiter (1-3 REarth is typical), periods less a day few months. For 32 planets, signal...
Abstract We present spectral observations of the multiplanet host TOI-1694 during transit TOI-1694b, a 26.1 M ⊕ hot Neptune with 3.77 day orbit. By analyzing radial velocities obtained from Keck Planet Finder, we modeled Rossiter–McLaughlin effect and constrained sky-projected obliquity to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>9</mml:mn> <mml:mo>°</mml:mo> </mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> <mml:msup>...
Abstract Hot Jupiters—short-period giant planets—were the first extrasolar planets to be discovered, but many questions about their origin remain. NASA’s Transiting Exoplanet Survey Satellite (TESS), an all-sky search for transiting planets, presents opportunity address these by constructing a uniform sample of hot Jupiters demographic study through new detections and unifying work previous ground-based transit surveys. As results effort build this large we report here discovery 10...
Abstract With JWST’s successful deployment and unexpectedly high fuel reserves, measuring the masses of sub-Neptunes transiting bright, nearby stars will soon become bottleneck for characterizing atmospheres small exoplanets via transmission spectroscopy. Using a carefully curated target list observations from more than 2 yr APF-Levy Keck-HIRES Doppler monitoring, TESS-Keck Survey is working toward alleviating this pressure. Here we present mass measurements 11 planets in eight systems that...
Multi-planet systems are valuable arenas for investigating exoplanet architectures and comparing planetary siblings. TOI-1246 is one such system, with a moderately bright K dwarf ($\rm{V=11.6,~K=9.9}$) four transiting sub-Neptunes identified by TESS orbital periods of $4.31~\rm{d},~5.90~\rm{d},~18.66~\rm{d}$, $~37.92~\rm{d}$. We collected 130 radial velocity observations Keck/HIRES TNG/HARPS-N to measure planet masses. refit the 14 sectors photometry refine radii ($\rm{2.97 \pm...
Abstract We present the stellar and planetary properties for 85 TESS Objects of Interest (TOIs) hosting 108 planet candidates that compose TESS-Keck Survey (TKS) sample. combine photometry, high-resolution spectroscopy, Gaia parallaxes to measure precise accurate properties. then use these parameters as inputs a light-curve processing pipeline recover signals homogeneously fit their transit Among fits, we detect significant transit-timing variations among at least three multiplanet systems...
Abstract We present optical spectroscopy of 710 solar neighborhood stars collected over 20 years to catalog chromospheric activity and search for stellar cycles. The California Legacy Survey are amenable exoplanet detection using precise radial velocities, we their Ca ii H K time series as a proxy activity. Using the High Resolution Echelle Spectrometer at Keck Observatory, measured flux in cores lines determine S -values on Mount Wilson scale <mml:math...
In this work we present the discovery and confirmation of two hot Jupiters orbiting red-giant stars, TOI-4377 b TOI-4551 b, observed by TESS in southern ecliptic hemisphere later followed-up with radial-velocity (RV) observations. For report a mass $0.957^{+0.089}_{-0.087} \ M_\mathrm{J}$ inflated radius $1.348 \pm 0.081 R_\mathrm{J}$ an evolved intermediate-mass star ($1.36 \mathrm{M}_\odot$, $3.52 \mathrm{R}_\odot$; TIC 394918211) on period $4.378$ days. $1.49 0.13 that is not obviously...
We report on the discovery and validation of a transiting long-period mini-Neptune orbiting bright (V = 9.0 mag) G dwarf (TOI 4633; R 1.05 RSun, M 1.10 MSun). The planet was identified in data from Transiting Exoplanet Survey Satellite by citizen scientists taking part Planet Hunters TESS project. Modeling transit events yields an orbital period 271.9445 +/- 0.0040 days radius 3.2 0.20 REarth. Earth-like incident flux 1.56 0.2 places it optimistic habitable zone around star. Doppler...
Abstract In 2010, Bakos and collaborators discovered a Neptune-sized planet transiting the K-dwarf HAT-P-11 every five days. Later in 2018, Yee reported an additional Jovian-mass companion on nine year orbit based decade of Doppler monitoring. The eccentric outer giant HAT-P-11c may be responsible for peculiar polar inner HAT-P-11b. However, Basilicata et al. recently suggested that signal could caused by stellar activity. this research note, we extend time series six years. combined data...
Hundreds of exoplanets between 1-1.8 times the size Earth have been discovered on close in orbits. However, these planets show such a diversity densities that some appear to be made entirely iron, while others host gaseous envelopes. To test this composition, we update masses 5 rocky (HD 93963 A b, Kepler-10 Kepler-100 Kepler-407 and TOI-1444 b) present confirmation new planet (TOI-1011) using 187 high precision RVs from Gemini/MAROON-X Keck/KPF. Our updated suggest compositions closer than...
Abstract We report spectropolarimetric observations of the Type Ia supernova (SN) SN 2021rhu at four epochs: −7, +0, +36, and +79 days relative to its B -band maximum luminosity. A wavelength-dependent continuum polarization peaking 3890 ± 93 Å reaching a level <?CDATA ${p}_{\max }\,=\,1.78 \% \pm 0.02$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>p</mml:mi> </mml:mrow> <mml:mi>max</mml:mi> </mml:msub> <mml:mspace width="0.50em"...
We present five epochs of near IR observations the protoplanetary disk around MWC 480 (HD31648) obtained with SpeX spectrograph on NASA's Infrared Telescope Facility (IRTF) between 2007 and 2013, inclusive. Using measured line fluxes in Pa beta Br gamma lines, we found mass accretion rates to be (1.43 - 2.61)x10^-8 Msun y^-1 (1.81 2.41)x10^-8 respectively, but which varied by more than 50% from epoch epoch. The spectral energy distribution (SED)reveals a variability about 30% 1.5 10 microns...
We report the discovery of an eccentric hot Neptune and a non-transiting outer planet around TOI-1272. identified eccentricity inner planet, with orbital period 3.3 d $R_{\rm p,b} = 4.1 \pm 0.2$ $R_\oplus$, based on mismatch between observed transit duration expected for circular orbit. Using ground-based radial velocity measurements from HIRES instrument at Keck Observatory, we measured mass TOI-1272b to be $M_{\rm 25 2$ $M_\oplus$. also confirmed high $e_b 0.34 0.06$, placing among most...