144 research outputs found
Solar Contamination in Extreme-precision Radial-velocity Measurements: Deleterious Effects and Prospects for Mitigation
Solar contamination, due to moonlight and atmospheric scattering of sunlight, can cause systematic errors in stellar radial velocity (RV) measurements that significantly detract from the ~10 cm s−1 sensitivity required for the detection and characterization of terrestrial exoplanets in or near habitable zones of Sun-like stars. The addition of low-level spectral contamination at variable effective velocity offsets introduces systematic noise when measuring velocities using classical mask-based or template-based cross-correlation techniques. Here we present simulations estimating the range of RV measurement error induced by uncorrected scattered sunlight contamination. We explore potential correction techniques, using both simultaneous spectrometer sky fibers and broadband imaging via coherent fiber imaging bundles, that could reliably reduce this source of error to below the photon-noise limit of typical stellar observations. We discuss the limitations of these simulations, the underlying assumptions, and mitigation mechanisms. We also present and discuss the components designed and built into the NEID (NN-EXPLORE Exoplanet Investigations with Doppler spectroscopy) precision RV instrument for the WIYN 3.5 m telescope, to serve as an ongoing resource for the community to explore and evaluate correction techniques. We emphasize that while "bright time" has been traditionally adequate for RV science, the goal of 10 cm s−1 precision on the most interesting exoplanetary systems may necessitate access to darker skies for these next-generation instruments
Detection of p-mode Oscillations in HD 35833 with NEID and TESS
We report the results of observations of p-mode oscillations in the G0
subgiant star HD 35833 in both radial velocities and photometry with NEID and
TESS, respectively. We achieve separate, robust detections of the oscillation
signal with both instruments (radial velocity amplitude m s, photometric amplitude
ppm, frequency of maximum power Hz, and
mode spacing Hz) as well as a non-detection in
a TESS sector concurrent with the NEID observations. These data shed light on
our ability to mitigate the correlated noise impact of oscillations with radial
velocities alone, and on the robustness of commonly used asteroseismic scaling
relations. The NEID data are used to validate models for the attenuation of
oscillation signals for exposure times , and we compare
our results to predictions from theoretical scaling relations and find that the
observed amplitudes are weaker than expected by , hinting at gaps in
the underlying physical models.Comment: 19 Pages, 14 Figures, Appendi
TOI-5375 B: A Very Low Mass Star at the Hydrogen-Burning Limit Orbiting an Early M-type Star
The TESS mission detected a companion orbiting TIC 71268730, categorized it
as a planet candidate, and designated the system TOI-5375. Our follow-up
analysis using radial velocity data from the Habitable-zone Planet Finder
(HPF), photometric data from Red Buttes Observatory (RBO), and speckle imaging
with NN-EXPLORE Exoplanet Stellar Speckle Imager (NESSI) determined that the
companion is a very low mass star (VLMS) near the hydrogen-burning mass limit
with a mass of 0.080\pm{0.002} M_{\Sun} (), a radius of
0.1114^{+0.0048}_{-0.0050} R_{\Sun} (1.0841), and
brightness temperature of K. This object orbits with a period of
1.721553 days around an early M dwarf star
(0.62\pm{0.016}M_{\Sun}). TESS photometry shows regular variations in the
host star's TESS light curve, which we interpreted as activity-induced
variation of 2\%, and used this variability to measure the host star's
stellar rotation period of 1.9716 days. The TOI-5375
system provides tight constraints on stellar models of low-mass stars at the
hydrogen-burning limit and adds to the population in this important region.Comment: 15 pages, 8 figures, Accepted to the Astronomical Journa
TOI-1670 c, a 40-day Orbital Period Warm Jupiter in a Compact System, is Well-aligned
We report the measurement of the sky-projected obliquity angle of
the Warm Jovian exoplanet TOI-1670 c via the Rossiter-McLaughlin effect as part
of the Stellar Obliquities in Long-period Exoplanet Systems (SOLES) project. We
observed the transit window during UT 20 April 2023 for 7 continuous hours with
NEID on the 3.5 m WIYN Telescope at Kitt Peak National Observatory. TOI-1670
hosts a sub-Neptune (P ~11 days; planet b) interior to the Warm Jovian (P ~40
days; planet c), which presents an opportunity to investigate the dynamics of a
Warm Jupiter with an inner companion. Additionally, TOI-1670 c is now among the
longest-period planets to date to have its sky-projected obliquity angle
measured. We find planet c is well-aligned to the host star, with =
-0.3 +/- 2.2 degrees. TOI-1670 c joins a growing census of aligned Warm
Jupiters around single stars and aligned planets in multi-planet systems.Comment: 11 pages, 2 figures, 1 table. Accepted to ApJ Letter
TOI-3785 b: A Low-Density Neptune Orbiting an M2-Dwarf Star
Using both ground-based transit photometry and high-precision radial velocity
(RV) spectroscopy, we confirm the planetary nature of TOI-3785 b. This
transiting Neptune orbits an M2-Dwarf star with a period of ~4.67 days, a
planetary radius of 5.14 +/- 0.16 Earth Radii, a mass of 14.95 +4.10, -3.92
Earth Masses, and a density of 0.61 +0.18, -0.17 g/cm^3. TOI-3785 b belongs to
a rare population of Neptunes (4 Earth Radii < Rp < 7 Earth Radii) orbiting
cooler, smaller M-dwarf host stars, of which only ~10 have been confirmed. By
increasing the number of confirmed planets, TOI-3785 b offers an opportunity to
compare similar planets across varying planetary and stellar parameter spaces.
Moreover, with a high transmission spectroscopy metric (TSM) of ~150 combined
with a relatively cool equilibrium temperature of 582 +/- 16 K and an inactive
host star, TOI-3785 b is one of the more promising low-density M-dwarf Neptune
targets for atmospheric follow-up. Future investigation into atmospheric mass
loss rates of TOI-3785 b may yield new insights into the atmospheric evolution
of these low-mass gas planets around M-dwarfs.Comment: 22 pages, 6 figures, 6 tables, Submitted to A
Solar Contamination in Extreme-precision Radial-velocity Measurements: Deleterious Effects and Prospects for Mitigation
Solar contamination, due to moonlight and atmospheric scattering of sunlight, can cause systematic errors in stellar radial velocity (RV) measurements that significantly detract from the ~10 cm s−1 sensitivity required for the detection and characterization of terrestrial exoplanets in or near habitable zones of Sun-like stars. The addition of low-level spectral contamination at variable effective velocity offsets introduces systematic noise when measuring velocities using classical mask-based or template-based cross-correlation techniques. Here we present simulations estimating the range of RV measurement error induced by uncorrected scattered sunlight contamination. We explore potential correction techniques, using both simultaneous spectrometer sky fibers and broadband imaging via coherent fiber imaging bundles, that could reliably reduce this source of error to below the photon-noise limit of typical stellar observations. We discuss the limitations of these simulations, the underlying assumptions, and mitigation mechanisms. We also present and discuss the components designed and built into the NEID (NN-EXPLORE Exoplanet Investigations with Doppler spectroscopy) precision RV instrument for the WIYN 3.5 m telescope, to serve as an ongoing resource for the community to explore and evaluate correction techniques. We emphasize that while "bright time" has been traditionally adequate for RV science, the goal of 10 cm s−1 precision on the most interesting exoplanetary systems may necessitate access to darker skies for these next-generation instruments
Solar Contamination in Extreme Precision Radial Velocity Measurements: Deleterious Effects and Prospects for Mitigation
Solar contamination, due to moonlight and atmospheric scattering of sunlight,
can cause systematic errors in stellar radial velocity (RV) measurements that
significantly detract from the ~10cm/s sensitivity required for the detection
and characterization of terrestrial exoplanets in or near Habitable Zones of
Sun-like stars. The addition of low-level spectral contamination at variable
effective velocity offsets introduces systematic noise when measuring
velocities using classical mask-based or template-based cross-correlation
techniques. Here we present simulations estimating the range of RV measurement
error induced by uncorrected scattered sunlight contamination. We explore
potential correction techniques, using both simultaneous spectrometer sky
fibers and broadband imaging via coherent fiber imaging bundles, that could
reliably reduce this source of error to below the photon-noise limit of typical
stellar observations. We discuss the limitations of these simulations, the
underlying assumptions, and mitigation mechanisms. We also present and discuss
the components designed and built into the NEID precision RV instrument for the
WIYN 3.5m telescope, to serve as an ongoing resource for the community to
explore and evaluate correction techniques. We emphasize that while "bright
time" has been traditionally adequate for RV science, the goal of 10cm/s
precision on the most interesting exoplanetary systems may necessitate access
to darker skies for these next-generation instruments
Stable fiber-illumination for extremely precise radial velocities with NEID
NEID is a high-resolution red-optical precision radial velocity (RV)
spectrograph recently commissioned at the WIYN 3.5 m telescope at Kitt Peak
National Observatory, Arizona, USA. NEID has an extremely stable environmental
control system, and spans a wavelength range of 380 to 930 nm with two
observing modes: a High Resolution (HR) mode at R 112,000 for maximum RV
precision, and a High Efficiency (HE) mode at R 72,000 for faint
targets. In this manuscript we present a detailed description of the components
of NEID's optical fiber feed, which include the instrument, exposure meter,
calibration system, and telescope fibers. Many parts of the optical fiber feed
can lead to uncalibratable RV errors, which cannot be corrected for using a
stable wavelength reference source. We show how these errors directly cascade
down to performance requirements on the fiber feed and the scrambling system.
We detail the design, assembly, and testing of each component. Designed and
built from the bottom-up with a single-visit instrument precision requirement
of 27 , close attention was paid to the error contribution
from each NEID subsystem. Finally, we include the lab and on-sky tests
performed during instrument commissioning to test the illumination stability,
and discuss the path to achieving the instrumental stability required to search
for a true Earth twin around a Solar-type star.Comment: Accepted in A
TOI-4201: An Early M-dwarf Hosting a Massive Transiting Jupiter Stretching Theories of Core-Accretion
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 and the Planet Finder
Spectrograph, we measure a planet mass of 2.59 M,
making this one of the most massive planets transiting an M-dwarf. The planet
is 0.4\% the mass of its 0.63 M host and may have a heavy
element mass comparable to the total dust mass contained in a typical Class II
disk. TOI-4201 b stretches our understanding of core-accretion during the
protoplanetary phase, and the disk mass budget, necessitating giant planet
formation to either take place much earlier in the disk lifetime, or perhaps
through alternative mechanisms like gravitational instability.Comment: To be submitted to AAS journals on 14th July 202
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