Paul A. Dalba
A5088501089- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Planetary Science and Exploration
- Gamma-ray bursts and supernovae
- Space Exploration and Technology
- Isotope Analysis in Ecology
- Astronomical and nuclear sciences
- Solar and Space Plasma Dynamics
- Astrophysical Phenomena and Observations
- History and Developments in Astronomy
- Geomagnetism and Paleomagnetism Studies
- Atmospheric Ozone and Climate
- Space Science and Extraterrestrial Life
- Adaptive optics and wavefront sensing
- Scientific Research and Discoveries
- Space exploration and regulation
- solar cell performance optimization
- Radioactive contamination and transfer
- Spacecraft and Cryogenic Technologies
- Ionosphere and magnetosphere dynamics
- Spacecraft Design and Technology
- Geology and Paleoclimatology Research
University of California, Santa Cruz
2021-2024
Search for Extraterrestrial Intelligence
2013-2024
University of California, Riverside
2019-2024
Boston University
2015-2019
Jet Propulsion Laboratory
2012-2013
California Institute of Technology
2012-2013
University of California, Berkeley
2012-2013
We present a high-precision radial velocity (RV) survey of 719 FGKM stars, which host 164 known exoplanets and 14 newly discovered or revised substellar companions. This catalog updated the orbital parameters long-period candidates, some have decades-longer observational baselines than they did upon initial detection. The range from warm sub-Neptunes super-Earths to cold gas giants. sample selection criteria, as well over 100,000 RV measurements, come Keck-HIRES, APF-Levy, Lick-Hamilton...
Abstract We used high-precision radial velocity measurements of FGKM stars to determine the occurrence giant planets as a function orbital separation spanning 0.03–30 au. Giant are more prevalent at distances 1–10 au compared orbits interior or exterior this range. The increase in planet ∼1 by factor ∼4 is highly statistically significant. A fall-off larger favored over models with flat increasing occurrence. measure <?CDATA ${14.1}_{-1.8}^{+2.0}$?> <mml:math...
Abstract We describe the discovery of a solar neighborhood ( d = 468 pc) binary system with main-sequence sunlike star and massive noninteracting black hole candidate. The spectral energy distribution visible is described by single stellar model. derive parameters from high signal-to-noise Magellan/MIKE spectrum, classifying as T eff 5972 K, <?CDATA $\mathrm{log}g=4.54$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mi>g</mml:mi>...
Abstract On 26 September 2022, the Double Asteroid Redirection Test (DART) spacecraft struck Dimorphos, a satellite of asteroid 65803 Didymos 1 . Because it is binary system, possible to determine how much orbit changed, as part test what necessary deflect an that might threaten Earth with impact. In nominal cases, pre-impact predictions orbital period reduction ranged from roughly 8.8 17 min (refs. 2,3 ). Here we report optical observations Dimorphos before, during and after impact,...
The James Webb Space Telescope (JWST) will likely revolutionize transiting exoplanet atmospheric science, due to a combination of its capability for continuous, long duration observations and larger collecting area, spectral coverage, resolution compared existing space-based facilities. However, it is unclear precisely how well JWST perform which myriad instruments observing modes be best suited studies. In this article, we describe prefatory Early Release Science (ERS) Cycle 1 program that...
We use a high-precision radial velocity survey of FGKM stars to study the conditional occurrence two classes planets: close-in small planets (0.023--1 au, 2--30 Earth masses) and distant giant (0.23--10 30--6000 masses). find that $41^{+15}_{-13}\%$ systems with close-in, planet also host an outer giant, compared $17.6^{+2.4}_{-1.9}\%$ for irrespective presence. This implies hosts may be enhanced in all $1.7\sigma$ significance. Conversely, we estimate $42^{+17}_{-13}\%$ cold inner planet,...
Abstract The search for habitable planets has revealed many that can vary greatly from an Earth analog environment. These include highly eccentric orbits, giant planets, different bulk densities, relatively active stars, and evolved stars. This work catalogs all found to reside in the zone (HZ) provides HZ boundaries, orbit characterization, potential spectroscopic follow-up observations. Demographics of are compared with a full catalog exoplanets. Extreme within highlighted, how their...
We present multiwavelength, multi-telescope, ground-based follow-up photometry of the white dwarf WD 1145+017, that has recently been suggested to be orbited by up six or more, short-period, low-mass, disintegrating planetesimals. detect 9 significant dips in flux between 10% and 30% stellar from our photometry. observe transits deeper than on average every ~3.6 hr This suggests 1145+017 is indeed being multiple, short-period objects. Through fits multiple asymmetric we observe, confirm...
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...
We present spectroscopic measurements of the Rossiter-McLaughlin effect for WASP-148b, only known hot Jupiter with a nearby warm-Jupiter companion, from WIYN/NEID and Keck/HIRES instruments. This is one first scientific results reported newly commissioned NEID spectrograph, as well second obliquity constraint system close-in after WASP-47. WASP-148b consistent being in alignment sky-projected spin axis host star, $\lambda=-8^{\circ}.2^{{+8^{\circ}.7}}_{-9^{\circ}.7}$. The low observed...
Giant planets on short-period orbits are predicted to be inflated and eventually engulfed by their host stars. However, the detailed timescales stages of these processes not well known. Here we present discovery three hot Jupiters (P $<$ 10 d) orbiting evolved, intermediate-mass stars ($M_\star$ $\approx$ 1.5 M$_\odot$, 2 R$_\odot$ $R_\star < $ 5 R$_\odot$). By combining \tess photometry with ground-based radial velocity measurements, report masses radii for between 0.4 1.8 M$_\mathrm{J}$...
Abstract The Kepler and TESS missions have demonstrated that planets are ubiquitous. However, the success of these heavily depends on ground-based radial velocity (RV) surveys, which combined with transit photometry can yield bulk densities orbital properties. While most host stars too faint for detailed follow-up observations, is detecting orbiting nearby bright more amenable to RV characterization. Here, we introduce TESS-Keck Survey (TKS), an program using ∼100 nights Keck/HIRES study...
Understanding the physical characteristics of Venus, including its atmosphere, interior, and evolutionary pathway with respect to Earth, remains a vital component for terrestrial planet evolution models emergence and/or decline planetary habitability. A statistical strategy evaluating pathways planets lies in atmospheric characterization exoplanets, where sample size provides sufficient means determining required runaway greenhouse conditions. Observations potential exoVenuses can help...
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...
Observations from Cassini VIMS and ISS show localized but extensive surface brightenings in the wake of 2010 September cloudburst. Four separate areas, all at similar latitude, changes: Yalaing Terra, Hetpet Regio, Concordia Adiri. Our analysis shows a general pattern to time-sequence after cloudburst areas darken for months, then brighten year before reverting their original spectrum. From rapid reversion timescale we infer that process driving brightening owes fine-grained solidified...
We use solar occultations observed by the Visual and Infrared Mapping Spectrometer aboard Cassini Spacecraft to extract 1 5 micron transmission spectrum of Saturn, as if it were a transiting exoplanet. detect absorption from methane, ethane, acetylene, aliphatic hydrocarbons, possibly carbon monoxide with peak-to-peak features up 90 parts-per-million despite presence ammonia clouds. also find that atmospheric refraction, opposed clouds or haze, determines minimum altitude could be probed...
White dwarf WD 1145+017 is orbited by several clouds of dust, possibly emanating from actively disintegrating bodies. These dust reveal themselves through deep, broad, and evolving transits in the star's light curve. Here, we report two epochs multi-wavelength photometric observations 1145+017, including filters optical, K$_\mathrm{s}$ 4.5 $\mu$m bands 2016 2017. The observed transit depths are different at these wavelengths. However, after correcting for excess emission $\mu$m, find white...
Abstract Over the past three decades, we have witnessed one of great revolutions in our understanding cosmos—the dawn Exoplanet Era. Where once knew just planetary system (the solar system), now know thousands, with new systems being announced on a weekly basis. Of thousands found to date, however, there is only that can study up-close and personal—the system. In this review, describe current for exoplanetary science community—with focus processes thought shaped see today. section one,...
We report the discovery of TOI-561, a multi-planet system in galactic thick disk that contains rocky, ultra-short period planet (USP). This bright ($V=10.2$) star hosts three small transiting planets identified photometry from NASA TESS mission: TOI-561 b (TOI-561.02, P=0.44 days, $R_b = 1.45\pm0.11\,R_\oplus$), c (TOI-561.01, P=10.8 $R_c=2.90\pm0.13\,R_\oplus$), and d (TOI-561.03, P=16.3 $R_d=2.32\pm0.16\,R_\oplus$). The is chemically ([Fe/H]$=-0.41\pm0.05$, [$\alpha$/H]$=+0.23\pm0.05$)...
Abstract Exoplanet systems with multiple transiting planets are natural laboratories for testing planetary astrophysics. One such system is HD 191939 (TOI 1339), a bright ( V = 9) and Sun-like (G9V) star, which TESS found to host three (b, c, d). The have periods of 9, 29, 38 days each similar sizes from 3 3.4 R ⊕ . To further characterize the system, we measured radial velocity (RV) over 415 Keck/HIRES APF/Levy. We find that M b 10.4 ± 0.9 c 7.2 1.4 , low compared most known comparable...
The alignment of planetary orbits with respect to the stellar rotation preserves information on their dynamical histories. Measuring this angle for young planets help illuminate mechanisms that create misaligned older planets, as different processes could operate over timescales ranging from a few Myr Gyr. We present spectroscopic transit observations exoplanet V1298 Tau b; we update age be $28\pm4$ based Gaia EDR3 measurements. observed partial Keck/HIRES and LBT/PEPSI, detected radial...
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,...
Warm Jupiters are close-in giant planets with relatively large planet-star separations (i.e., $10< a/R_\star <100$). Given their weak tidal interactions host stars, measurements of stellar obliquity may be used to probe the initial distribution and dynamical history for gas giants. Using spectroscopic observations, we confirm planetary nature TOI-1859b determine TOI-1859 $\lambda = 38.9^{+2.8}_{-2.7}\deg$ relative its companion using Rossiter-McLaughlin effect. is a 64-day warm Jupiter...
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 Giant exoplanets orbiting close to their host stars are unlikely have formed in present configurations 1 . These ‘hot Jupiter’ planets instead thought migrated inward from beyond the ice line and several viable migration channels been proposed, including eccentricity excitation through angular-momentum exchange with a third body followed by tidally driven orbital circularization 2,3 The discovery of extremely eccentric ( e = 0.93) giant exoplanet HD 80606 b (ref. 4 ) provided...