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Solvated-electron production by cyanocuprates is compatible with the UV-environment on the Haden-Archaean Earth

Journal Article

UV-driven photoredox processing of cyanocuprates can generate simple sugars necessary for prebiotic synthesis. We investigate the wavelength dependence of this process from 215 to 295 nm and generally observe faster rates at shorter wavelengths. The most...

TESS Discovery of an Ultra-short-period Planet around the Nearby M Dwarf LHS 3844

Journal Article

Data from the newly commissioned Transiting Exoplanet Survey Satellite has revealed a "hot Earth" around LHS 3844, an M dwarf located 15 pc away. The planet has a radius of  R _⊕ and orbits the star every 11 hr. Although the existence of an atmosphere...

A New Desalination Pump Help Define the pH of Ocean Worlds

Journal Article

We study ocean exoplanets, for which the global surface ocean is separated from the rocky interior by a high-pressure ice mantle. We describe a mechanism that can pump salts out of the ocean, resulting in oceans of very low salinity. Here we focus on the...

TESS Discovery of a Transiting Super-Earth in the pi Mensae System

Journal Article

We report the detection of a transiting planet around π Men (HD 39091), using data from the Transiting Exoplanet Survey Satellite (TESS). The solar-type host star is unusually bright (V = 5.7) and was already known to host a Jovian planet on a highly...

UV photostability of three 2-aminoazoles with key roles in prebiotic chemistry on the early earth†

Journal Article

Three related molecules in the 2-aminoazole family are potentially important for prebiotic chemistry: 2-aminooxazole, 2-aminoimidazole, and 2-aminothiazole, which can provide critical functions as an intermediate in nucleotide synthesis, a nucleotide...

UV‐Induced Charge‐Transfer States in Short Guanosine‐Containing DNA Oligonucleotides

Journal Article

Charge transfer has proven to be an important mechanism in DNA photochemistry. In particular, guanine (dG) plays a major role as an electron donor, but the photophysical dynamics of dG‐containing charge‐transfer states have not been extensively...

Ultraviolet-Driven Deamination of Cytidine Ribonucleotides Under Planetary Conditions

Journal Article

A previously proposed synthesis of pyrimidine ribonucleotides makes use of ultraviolet (UV) light to convert β-uc(d)-ribocytidine-2',3'-cyclic phosphate to β-uc(d)-ribouridine-2',3'-cyclic phosphate, while simultaneously selectively degrading synthetic...

K2-263 b: a 50 d period sub-Neptune with a mass measurement using HARPS-N

Journal Article

This paper reports on the validation and mass measurement of K2-263 b, a sub-Neptune orbiting a quiet G9V star. Using K2 data from campaigns C5 and C16, we find this planet to have a period of 50.818947 ± 0.000094 d and a radius of 2.41 ± 0.12 R_⊕. We...

Growth model interpretation of planet size distribution

Journal Article

The radii and orbital periods of 4,000+ confirmed/candidate exoplanets have been precisely measured by the Kepler mission. The radii show a bimodal distribution, with two peaks corresponding to smaller planets (likely rocky) and larger intermediate-size...

Masses and radii for the three super-Earths orbiting GJ 9827, and implications for the composition of small exoplanets

Journal Article

Super-Earths belong to a class of planet not found in the Solar system, but which appear common in the Galaxy. Given that some super-Earths are rocky, while others retain substantial atmospheres, their study can provide clues as to the formation of both...

K2-291b: A Rocky Super-Earth in a 2.2 day Orbit

Journal Article

K2-291 is a solar-type star with a radius of R _* = 0.899 ± 0.034 R _⊙ and mass of M_* = 0.934 ± 0.038 M _⊙. From the K2 C13 data, we found one super-Earth planet (R _p  =  R _⊕) transiting this star on a short period orbit (P =  days). We followed this system...

Three years of Sun-as-a-star radial-velocity observations on the approach to solar minimum

Journal Article

The time-variable velocity fields of solar-type stars limit the precision of radial-velocity determinations of their planets’ masses, obstructing detection of Earth twins. Since 2015 July, we have been monitoring disc-integrated sunlight in daytime using...