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Full list of authors: Turtelboom, Emma V.; Weiss, Lauren M.; Dressing, Courtney D.; Nowak, Grzegorz; Pallé, Enric; Beard, Corey; Blunt, Sarah; Brinkman, Casey; Chontos, Ashley; Claytor, Zachary R.; Dai, Fei; Dalba, Paul A.; Giacalone, Steven; Gonzales, Erica; Harada, Caleb K.; Hill, Michelle L.; Holcomb, Rae; Korth, Judith; Lubin, Jack; Masseron, Thomas; MacDougall, Mason; Mayo, Andrew W.; Močnik, Teo; Akana Murphy, Joseph M.; Polanski, Alex S.; Rice, Malena; Rubenzahl, Ryan A.; Scarsdale, Nicholas; Stassun, Keivan G.; Tyler, Dakotah B.; Zandt, Judah Van; Crossfield, Ian J. M.; Deeg, Hans J.; Fulton, Benjamin; Gandolfi, Davide; Howard, Andrew W.; Huber, Dan; Isaacson, Howard; Kane, Stephen R.; Lam, Kristine W. F.; Luque, Rafael; Martín, Eduardo L.; Morello, Giuseppe; Orell-Miquel, Jaume; Petigura, Erik A.; Robertson, Paul; Roy, Arpita; Van Eylen, Vincent; Baker, David; Belinski, Alexander A.; Bieryla, Allyson; Ciardi, David R.; Collins, Karen A.; Cutting, Neil; Della-Rose, Devin J.; Ellingsen, Taylor B.; Furlan, E.; Gan, Tianjun; Gnilka, Crystal L.; Guerra, Pere; Howell, Steve B.; Jimenez, Mary; Latham, David W.; Larivière, Maude; Lester, Kathryn V.; Lillo-Box, Jorge; Luker, Lindy; Mann, Christopher R.; Plavchan, Peter P.; Safonov, Boris; Skinner, Brett; Strakhov, Ivan A.; Wittrock, Justin M.; Caldwell, Douglas A.; Essack, Zahra; Jenkins, Jon M.; Quintana, Elisa V.; Ricker, George R.; Vanderspek, Roland; Seager, S.; Winn, Joshua N.-- This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., Multiplanet systems are valuable arenas for investigating exoplanet architectures and comparing planetary siblings. TOI-1246 is one such system, with a moderately bright K dwarf (V = 11.6, K = 9.9) and four transiting sub-Neptunes identified by TESS with orbital periods of 4.31, 5.90, 18.66, and 37.92 days. We collected 130 radial velocity observations with Keck/HIRES and TNG/HARPS-N to measure planet masses. We refit the 14 sectors of TESS photometry to refine planet radii (2.97 ± 0.06 R⊕, 2.47 ± 0.08 R⊕, 3.46 ± 0.09 R⊕, and 3.72 ± 0.16 R⊕) and confirm the four planets. We find that TOI-1246 e is substantially more massive than the three inner planets (8.1 ± 1.1 M⊕, 8.8 ± 1.2 M⊕, 5.3 ± 1.7 M⊕, and 14.8 ± 2.3 M⊕). The two outer planets, TOI-1246 d and TOI-1246 e, lie near to the 2:1 resonance (Pe/Pd = 2.03) and exhibit transit-timing variations. TOI-1246 is one of the brightest four-planet systems, making it amenable for continued observations. It is one of only five systems with measured masses and radii for all four transiting planets. The planet densities range from 0.70 ± 0.24 to 3.21 ± 0.44 g cm−3, implying a range of bulk and atmospheric compositions. We also report a fifth planet candidate found in the RV data with a minimum mass of 25.6 ± 3.6 M⊕. This planet candidate is exterior to TOI-1246 e, with a candidate period of 93.8 days, and we discuss the implications if it is confirmed to be planetary in nature. © 2022. The Author(s). Published by the American Astronomical Society., We thank the time assignment committees of the University of California, the California Institute of Technology, NASA, and the University of Hawaii for supporting the TESS-Keck Survey with observing time at Keck Observatory. We thank NASA for funding associated with our Key Strategic Mission Support project. We gratefully acknowledge the efforts and dedication of the Keck Observatory staff for support of HIRES and remote observing. We recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has within the indigenous Hawaiian community. We are deeply grateful to have the opportunity to conduct observations from this mountain. We thank Ken and Gloria Levy, who supported the construction of the Levy Spectrometer on the Automated Planet Finder. We thank the University of California and Google for supporting Lick Observatory, and the UCO staff for their dedicated work scheduling and operating the telescopes of Lick Observatory. This paper is based on data collected by the TESS mission. Funding for the TESS mission is provided by the NASA Explorer Program. C.D. gratefully acknowledges support from the David & Lucile Packard Foundation and the Alfred P. Sloan Foundation. A.A.B., B.S.S., and I.A.S. acknowledge the support of the Ministry of Science and Higher Education of the Russian Federation under the grant 075-15-2020-780(N13.1902.21.0039). J.K. gratefully acknowledges the support of the Swedish National Space Agency (SNSA; DNR 2020-00104). A.W.M. is supported by the NSF Graduate Research Fellowship grant No. DGE 1752814. J.M.A.M. is supported by the National Science Foundation Graduate Research Fellowship Program under grant No. DGE-1842400. J.M.A.M. acknowledges the LSSTC Data Science Fellowship Program, which is funded by LSSTC, NSF Cybertraining grant No. 1829740, the Brinson Foundation, and the Moore Foundation; his participation in the program has benefited this work. C.K.H. acknowledges support from the National Science Foundation Graduate Research Fellowship Program under grant No. DGE 2146752. M.R. is supported by the National Science Foundation Graduate Research Fellowship Program under grant No. DGE-1752134. R.A.R. is supported by an NSF Graduate Research Fellowship, grant No. DGE 1745301. P.D. is supported by a National Science Foundation (NSF) Astronomy and Astrophysics Postdoctoral Fellowship under award AST-1903811. R.L. acknowledges financial support from the Centre of Excellence "Severo Ochoa" award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). D.H. acknowledges support from the Alfred P. Sloan Foundation and the National Aeronautics and Space Administration (80NSSC20K0593, 80NSSC21K0652). T.M. acknowledges financial support from the Spanish Ministry of Science and Innovation (MICINN) through the Spanish State Research Agency, under the Severo Ochoa Program 2020-2023 (CEX2019-000920-S). K.W.F.L. acknowledges support by DFG grants RA714/14-1 within the DFG Schwerpunkt SPP 1992, "Exploring the Diversity of Extrasolar Planets."

Close double degenerate binaries are one of the favoured progenitor channels for type Ia supernovae, but it is unclear how many suitable systems there are in the Galaxy. We report results of a large radial velocity survey for double degenerate (DD) binaries using the UVES spectrograph at the ESO VLT (ESO SN Ia Progenitor surveY – SPY). Exposures taken at different epochs are checked for radial velocity shifts indicating close binary systems. We observed 689 targets classified as DA white dwarfs (displaying hydrogen-rich atmospheres), of which 46 were found to possess a cool companion. We measured radial velocities (RV) of the remaining 643 DA white dwarfs. We managed to secure observations at two or more epochs for 625 targets, supplemented by eleven objects meeting our selection criteria from literature. The data reduction and analysis methods applied to the survey data are described in detail. The sample contains 39 double degenerate binaries, only four of which were previously known. Twenty are double-lined systems, in which features from both components are visible, the other 19 are single-lined binaries. We provide absolute RVs transformed to the heliocentric system suitable for kinematic studies. Our sample is large enough to sub-divide by mass: 16 out of 44 low mass targets (≤0.45 M⊙) are detected as DDs, while just 23 of the remaining 567 targets with multiple spectra and mass > 0.45 M⊙are double. The detected fraction amongst the low mass objects (36.4 ± 7.3%) is significantly higher than for the higher-mass, carbon-oxygen core dominated part of the sample (3.9 ± 0.8%), but it is much lower than expected from the detection efficiency for companion masses of 0.05 M⊙or higher and a 100% binary fraction. This suggests either companion stars of with a mass below 0.05 M⊙or some of the low mass white dwarfs are single.

Methods for manufacturing and characterizing permanent-magnet-based short-period undulators are presented. Two fabrication methods, differing by the dimension range of their magnetic period, are described: the mini-undulator, with magnetic periods ranging from 1 mm to 200 μm, fabricated by laser micromachining bulk permanent magnets; and the micro-undulator, with magnetic periods from 200 μm to 10 μm, fabricated by electroplating or sputtering a hard magnetic material onto silicon. The undulator gaps vary from 500 μm down to tens of microns, corresponding to the reduction of the magnetic period. Undulator peak magnetic fields can reach up to 0.7 T while maintaining a reasonable undulator gap. Using these short-period undulators, high-photon-energy radiation can be generated at lower electron beam energies compared to current state-of-the-art undulators.

We report the first planet discovery from the two-wheeled Kepler (K2) mission: HIP 116454 b. The host star HIP 116454 is a bright (V = 10.1, K = 8.0) K1-dwarf with high proper motion, and a parallax-based distance of 55.2 +/- 5.4 pc. Based on high-resolution optical spectroscopy, we find that the host star is metal-poor with [Fe/H] = -.16 +/- .18, and has a radius R = 0.716 +/- .0024 R_sun and mass M = .775 +/- .027 Msun. The star was observed by the Kepler spacecraft during its Two-Wheeled Concept Engineering Test in February 2014. During the 9 days of observations, K2 observed a single transit event. Using a new K2 photometric analysis technique we are able to correct small telescope drifts and recover the observed transit at high confidence, corresponding to a planetary radius of Rp = 2.53 +/- 0.18 Rearth. Radial velocity observations with the HARPS-N spectrograph reveal a 11.82 +/- 1.33 Mearth planet in a 9.1 day orbit, consistent with the transit depth, duration, and ephemeris. Follow-up photometric measurements from the MOST satellite confirm the transit observed in the K2 photometry and provide a refined ephemeris, making HIP 116454 b amenable for future follow-up observations of this latest addition to the growing population of transiting super-Earths around nearby, bright stars., Comment: 16 pages, 8 figures. Accepted by ApJ

The results of a search for eclipsing Am star binaries using photometry from the SuperWASP survey are presented. The light curves of 1742 Am stars fainter than V = 8.0 were analysed for the presence of eclipses. A total of 70 stars were found to exhibit eclipses, with 66 having sufficient observations to enable orbital periods to be determined and 28 of which are newly identified eclipsing systems. Also presented are spectroscopic orbits for 5 of the systems. The number of systems and the period distribution is found to be consistent with that identified in previous radial velocity surveys of " classical" Am stars. Fil: Smalley, B.. Keele University; Reino Unido Fil: Southworth, J.. Keele University; Reino Unido Fil: Pintado, Olga Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; Argentina Fil: Gillon, M.. Université de Liege; Bélgica Fil: Holdsworth, D. L.. Keele University; Reino Unido Fil: Anderson, D. R.. Keele University; Reino Unido Fil: Barros, S. C. C.. Aix-Marseille Université; Francia. Centre National de la Recherche Scientifique; Francia Fil: Collier Cameron, A.. University of St. Andrews; Reino Unido Fil: Delrez, L.. Université de Liege; Bélgica Fil: Faedi, F.. University of Warwick; Reino Unido Fil: Haswell, C. A.. Open University; Reino Unido Fil: Hellier, C.. Keele University; Reino Unido Fil: Horne, K.. University of St. Andrews; Reino Unido Fil: Jehin, E.. Université de Liege; Bélgica Fil: Maxted, P. F. L.. Keele University; Reino Unido Fil: Norton, Andrew. Open University; Reino Unido Fil: Pollacco, D.. University of Warwick; Reino Unido Fil: Skillen, I.. Isaac Newton Group of Telescopes; España Fil: Smith, A. M. S.. Polish Academy of Sciences; Argentina Fil: West, R. G.. University of Warwick; Reino Unido Fil: Wheatley, P. J.. University of Warwick; Reino Unido

As part of a collaborative program between British Antarctic Survey and Utah State University, measurements were made using an all-sky airglow imager located at the U.K. Halley Station (76°S, 27°W) during the 2000 and 2001 austral winter seasons from April through to early September. A co-located imaging Doppler interferometer was utilized to obtain coincident wind measurements for a total of 171 wave events. This study comprises the first detailed climatological investigation of the propagation nature (freely propagating, Doppler ducted, or evanescent) of individual quasi-monochromatic, short-period wave events at a high southern latitude. Distributions of the derived vertical wavelength exhibit an interquartile range from ∼16-48 km with a median vertical wavelength of 21 km. The majority of the wave events were found to be freely propagating waves, with only ∼5% exhibiting a clear Doppler ducted signature, while 15% of the waves were found to be evanescent in nature. Although no coincident temperature measurements were available, subsequent SABER temperature measurements suggest that up to ∼28% of the measured temperature profiles are capable of providing a ducted environment for the observed wave field. This is in sharp contrast to findings at mid-and low latitudes where these waves have been shown to be prone to Doppler ducted motion. It is suggested that the relatively weak wind field and associated tidal wind amplitudes over Halley are not capable of forming a significant Doppler ducted region to sustain a substantial amount of ducted waves belonging to the detectable spectrum of the airglow imager. As these wind fields are comparable to wind fields found at other polar latitudes, we hypothesize that the majority of short-period gravity waves observed in the polar mesosphere are freely propagating and thus an important source of energy transfer into the MLT region. Copyright 2012 by the American Geophysical Union.

Except for some narrowband photometric observations obtained by A´Hearn et al. (1995), in literature there is no other information available about Comet 85P/Boethin´s activity, such as mass loss and nuclear size for this shortperiod (~11.2 years) comet. In an effort to find more information about this object, we have used visual magnitude measurements available from International Comet Quarterly (ICQ) to obtain the water production rates (in molecules s-1) related to its perihelion passage of 1986 by applying the Semi-Empirical Method of Visual Magnitudes-SEMVM (de Almeida et al., 1997; Sanzovo et al., 2001). When associated to Delsemme’s (1982) water vaporization theory, these rates allowed for the calculus of the dimension of the effective minimum nuclear radius of the comet. The water production rates were then converted into gas production rates (in g s-1) so that, applying the correlation between gas and dust found for eleven periodic and three non-periodic comets deduced by Trevisan Sanzovo (2006), we have obtained the dust loss rates (in g s-1), its behavior with the heliocentric distance and the dust-to-gas ratios for this little-known comet.

Electron transfer from GaAs wells (Gamma wavefunctions) to AlAs barriers (X wavefunctions) in GaAs / AlAs type II superlattices has been studied by time resolved luminescence with femtosecond resolution. Transfer times can be as short as 140 fs for narrow wells and as long as 25 ps for the widest wells. They do not depend appreciably on the barrier thickness. We discuss the possible contribution to the transfer mechanism of state mixing, intervalley scattering and Frolich interaction. Our measurement favors phonon assisted, intervalley type scattering, modified by the overlap of the different wavefunctions.