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Poster presented at the Exoclimes VI conference. Contact: d.c.linssen@uva.nl

Observations of helium in exoplanet atmospheres may reveal the presence of large gaseous envelopes, and indicate ongoing atmospheric escape. Orell-Miquel et al. (2022) used CARMENES to measure a tentative detection of helium for the sub-Neptune GJ 1214b, with a peak excess absorption reaching over 2% in transit depth at 10830 Angstroms. However, several non-detections of helium had previously been reported for GJ 1214b. One explanation for the discrepancy was contamination of the planetary signal by overlapping telluric absorption- and emission lines. We used Keck/NIRSPEC to observe another transit of GJ 1214b at 10830 Angstroms, at a time of minimal contamination by telluric lines, and did not observe planetary helium absorption. Accounting for correlated noise in our measurement, we place an upper limit on the excess absorption size of 1.22% (95% confidence). We find that the discrepancy between the CARMENES and NIRSPEC observations is unlikely to be caused by using different instruments or stellar activity. It is currently unclear whether the difference is due to correlated noise in the observations, or variability in the planetary atmosphere., Accepted for publication in ApJL

Atmospheric escape is believed to significantly influence the evolution of close-in exoplanets, and has been proposed to shape planetary demographics in the form of the hot Neptune desert and evaporation valley. In order to test these theories, it is crucial to obtain accurate estimates of the atmospheric mass-loss rate for evaporating exoplanets. Strong absorption during transit in the helium line at 1083 nm has recently proven a powerful direct observational tracer of atmospheric escape. A common approach to extracting mass-loss rates from these observations is to fit synthetic line profiles based on models that parametrize the planetary outflow in terms of the mass-loss rate and a constant temperature. However, such analyses often result in degeneracies between the mass-loss rate and temperature, making it difficult to narrowly constrain either parameter. We place additional theoretical constraints on the allowed temperature by simulating outflow models with the photo-ionization code Cloudy, which ensures a highly detailed NLTE treatment of the gas. Combining the two constraints allows us to find much tighter estimates for the atmospheric mass-loss rate. We demonstrate this here for the helium line, but our methodscan be applied to many other spectral lines in the visible and ultraviolet wavelength range, which are inherently included in Cloudy, in order to probe different layers of the escaping atmospheres and thus get a better insight into their properties.

Transit surveys indicate that there is a deficit of Neptune-sized planets on close-in orbits. If this ``Neptune desert' is entirely cleared out by atmospheric mass loss, then planets at its upper edge should only be marginally stable against photoevaporation, exhibiting strong outflow signatures in tracers like the metastable helium triplet. We test this hypothesis by carrying out a 12-night photometric survey of the metastable helium feature with Palomar/WIRC, targeting seven gas-giant planets orbiting K-type host stars. Eight nights of data are analyzed here for the first time along with reanalyses of four previously-published datasets. We strongly detect helium absorption signals for WASP-69b, HAT-P-18b, and HAT-P-26b; tentatively detect signals for WASP-52b and NGTS-5b; and do not detect signals for WASP-177b and WASP-80b. We interpret these measured excess absorption signals using grids of Parker wind models to derive mass-loss rates, which are in good agreement with predictions from the hydrodynamical outflow code ATES for all planets except WASP-52b and WASP-80b, where our data suggest that the outflows are much smaller than predicted. Excluding these two planets, the outflows for the rest of the sample are consistent with a mean energy-limited outflow efficiency of $\varepsilon = 0.41^{+0.16}_{-0.13}$. Even when we make the relatively conservative assumption that gas-giant planets experience energy-limited outflows at this efficiency for their entire lives, photoevaporation would still be too inefficient to carve the upper boundary of the Neptune desert. We conclude that this feature of the exoplanet population is a pristine tracer of giant planet formation and migration mechanisms., 31 pages, 14 figures, accepted to AJ

We report observations of the recently discovered warm Neptune TOI-674 b (5.25 \rearth{}, 23.6 \mearth{}) with the Hubble Space Telescope's Wide Field Camera 3 instrument. TOI-674 b is in the Neptune desert, an observed paucity of Neptune-size exoplanets at short orbital periods. Planets in the desert are thought to have complex evolutionary histories due to photoevaporative mass loss or orbital migration, making identifying the constituents of their atmospheres critical to understanding their origins. We obtained near-infrared transmission spectroscopy of the planet's atmosphere with the G141 grism. After extracting, detrending, and fitting the spectral lightcurves to measure the planet's transmission spectrum, we used the petitRADTRANS atmospheric spectral synthesis code to perform retrievals on the planet's atmosphere to identify which absorbers are present. These results show moderate evidence for increased absorption at 1.4 $\mu$m due to water vapor at 2.9$\sigma$ (Bayes factor = 15.8), as well as weak evidence for the presence of clouds at 2.2$\sigma$ (Bayes factor = 4.0). TOI-674 b is a strong candidate for further study to refine the water abundance, which is poorly constrained by our data. We also incorporated new TESS short-cadence optical photometry, as well as Spitzer/IRAC data, and re-fit the transit parameters for the planet. We find the planet to have the following transit parameters: $R_p/R_* = 0.1135\pm0.0006$, $T_0 = 2458544.523792\pm0.000452$ BJD, and $P = 1.977198\pm0.00007$ d. These measurements refine the planet radius estimate and improve the orbital ephemerides for future transit spectroscopy observations of this highly intriguing warm Neptune., Comment: Accepted to the Astronomical Journal. 20 pages, 17 figures

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.--Full list of authors: Barragan, O.; Armstrong, D. J.; Gandolfi, D.; Carleo, I; Vidotto, A. A.; D'Angelo, C. Villarreal; Oklopcic, A.; Isaacson, H.; Oddo, D.; Collins, K.; Fridlund, M.; Sousa, S. G.; Persson, C. M.; Hellier, C.; Howell, S.; Howard, A.; Redfield, S.; Eisner, N.; Georgieva, I. Y.; Dragomir, D.; Bayliss, D.; Nielsen, L. D.; Klein, B.; Aigrain, S.; Zhang, M.; Teske, J.; Twicken, J. D.; Jenkins, J.; Esposito, M.; Van Eylen, V.; Rodler, F.; Adibekyan, V; Alarcon, J.; Anderson, D. R.; Murphy, J. M. Akana; Barrado, D.; Barros, S. C. C.; Benneke, B.; Bouchy, F.; Bryant, E. M.; Butler, R. P.; Burt, J.; Cabrera, J.; Casewell, S.; Chaturvedi, P.; Cloutier, R.; Cochran, W. D.; Crane, J.; Crossfield, I; Crouzet, N.; Collins, K., I; Dai, F.; Deeg, H. J.; Deline, A.; Demangeon, O. D. S.; Dumusque, X.; Figueira, P.; Furlan, E.; Gnilka, C.; Goad, M. R.; Goffo, E.; Gutierrez-Canales, F.; Hadjigeorghiou, A.; Hartman, Z.; Hatzes, A. P.; Harris, M.; Henderson, B.; Hirano, T.; Hojjatpanah, S.; Hoyer, S.; Kabath, P.; Korth, J.; Lillo-Box, J.; Luque, R.; Marmier, M.; Mocnik, T.; Muresan, A.; Murgas, F.; Nagel, E.; Osborne, H. L. M.; Osborn, A.; Osborn, H. P.; Palle, E.; Raimbault, M.; Ricker, G. R.; Rubenzahl, R. A.; Stockdale, C.; Santos, N. C.; Scott, N.; Schwarz, R. P.; Shectman, S.; Seager, S.; Segransan, D.; Serrano, L. M.; Skarka, M.; Smith, A. M. S.; Subjak, J.; Tan, T. G.; Udry, S.; Watson, C.; Wheatley, P. J.; West, R.; Winn, J. N.; Wang, S. X.; Wolfgang, A.; Ziegler, C.; KESPRINT Team., We present the discovery and characterization of two transiting planets observed by TESS in the light curves of the young and bright (V = 9.67) star HD73583 (TOI-560). We perform an intensive spectroscopic and photometric space- and ground-based follow-up in order to confirm and characterize the system. We found that HD73583 is a young (∼500 Myr) active star with a rotational period of 12.08 ± 0.11 d, and a mass and radius of 0.73 ± 0.02 M⊙ and 0.65 ± 0.02 R⊙, respectively. HD 73583 b (Pb = 6.3980420+0.0000067−0.0000062 d) has a mass and radius of 10.2+3.4−3.1 M⊕ and 2.79 ± 0.10 R⊕, respectively, which gives a density of 2.58+0.95−0.81 gcm−3⁠. HD 73583 c (Pc = 18.87974+0.00086−0.00074 d) has a mass and radius of 9.7+1.8−1.7 M⊕ and 2.39+0.10−0.09 R⊕, respectively, which translates to a density of 3.88+0.91−0.80 gcm−3⁠. Both planets are consistent with worlds made of a solid core surrounded by a volatile envelope. Because of their youth and host star brightness, they both are excellent candidates to perform transmission spectroscopy studies. We expect ongoing atmospheric mass-loss for both planets caused by stellar irradiation. We estimate that the detection of evaporating signatures on H and He would be challenging, but doable with present and future instruments. © The Author(s) 2022. Published by Oxford University Press on behalf of Royal Astronomical Society., This work was supported by the KESPRINT collaboration, an international consortium devoted to the characterization and research of exoplanets discovered with space-based missions (http://www.kesprint.science). We thank the referee for their helpful comments and suggestions that improved the quality of this manuscript. We acknowledge the use of public TESS data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. This work uses observations from the LCOGT network. Part of the LCOGT telescope time was granted by NOIRLab through the Mid-Scale Innovations Program (MSIP). MSIP is funded by NSF. This paper is in part based on data collected under the NGTS project at the ESO La Silla Paranal Observatory. The NGTS facility is operated by the consortium institutes with support from the UK Science and Technology Facilities Council (STFC) projects ST/M001962/1 and ST/S002642/1. This research has used the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Some of the observations in the paper used the High-Resolution Imaging instrument Zorro obtained under Gemini LLP Proposal Number: GN/S-2021A-LP-105. Zorro was funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. Zorro was mounted on the Gemini North (and/or South) telescope of the international Gemini Observatory, a program of NSF’s OIR Lab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (United States), National Research Council (Canada), Agencia Nacional de Investigación y Desarrollo (Chile), Ministerio de Ciencia, Tecnología e Innovación (Argentina), Ministério da Ciência, Tecnologia, Inovações e Comunicações (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). OB, BK, and SA acknowledge that this publication is part of a project that has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 865624). DG and LMS gratefully acknowledge financial support from the Cassa di Risparmio di Torino foundation under Grant No. 2018.2323 ‘Gaseous or rocky? Unveiling the nature of small worlds’. DJA acknowledges support from the STFC via an Ernest Rutherford Fellowship (ST/R00384X/1). APH and ME acknowledges grant HA 3279/12-1 within the DFG Schwerpunkt SPP 1992, ‘Exploring the Diversity of Extrasolar Planets’. JS and PK would like to acknowledge support from MSMT grant LTT-20015. We acknowledges the support by FCT – Fundação para a Ciência e a Tecnologia through national funds and by FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalização by these grants: UID/FIS/04434/2019; UIDB/04434/2020; UIDP/04434/2020; PTDC/FIS-AST/32113/2017 & POCI-01-0145-FEDER-032113; PTDC/FISAST /28953/2017 & POCI-01-0145-FEDER-028953. AD acknowledges the financial support of the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project FOUR ACES; grant agreement No 724427). AD also acknowledges financial support of the the Swiss National Science Foundation (SNSF) through the National Centre for Competence in Research ‘PlanetS’. MF, IYG, JK, and CMP gratefully acknowledge the support of the Swedish National Space Agency (DNR 177/19, 174/18, 2020-00104, 65/19). FGC thanks the Mexican national council for science and technology (CONACYT, CVU-1005374). MS acknowledge financial support of the Inter-transfer grant no LTT-20015. JL-B acknowledges financial support received from ‘la Caixa’ Foundation (ID 100010434) and from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 847648, with fellowship code LCF/BQ/PI20/11760023. AAV acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 817540, ASTROFLOW). JMAM is supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1842400. JMAM 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. RAR is supported by the NSF Graduate Research Fellowship, grant No. DGE 1745301. RL acknowledges financial support from the Spanish Ministerio de Ciencia e Innovación, through project PID2019-109522GB-C52, and the Centre of Excellence ‘Severo Ochoa’ award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). PC acknowledges the generous support from Deutsche Forschungsgemeinschaft (DFG) of the grant CH 2636/1-1. SH acknowledges CNES funding through the grant 837319. VA acknowledges the support from Fundação para a Ciência e Tecnologia (FCT) through Investigador FCT contract nr. IF/00650/2015/CP1273/CT0001. ODSD is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through Fundação para a Ciência e Tecnologia (FCT). AO is supported by an STFC studentship. XD would like to acknowledge the funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement SCORE No 851555). HJD acknowledges support from the Spanish Research Agency of the Ministry of Science and Innovation (AEI-MICINN) under the grant ‘Contribution of the IAC to the PLATO Space Mission’ with reference PID2019-107061GB-C66, DOI: 10.13039/501100011033. DD acknowledges support from the TESS Guest Investigator Program grant 80NSSC19K1727 and NASA Exoplanet Research Program grant 18-2XRP18_2-0136. AO gratefully acknowledges support from the Dutch Research Council NWO Veni grant.

In Agatha Christie’s literary career, which spanned over more than fifty years, the tally of murdered people approached three hundred. Her job as a nurse during World War I left a lasting mark on her career because during that period she developed a special interest in chemistry, which later influenced her writing style and using poison became her forte. Consequently, many of her literary characters fell victim to some kind of toxin. However, a large part of her works features a wide array of more violent and manual death causes. Most of those crimes are solved by one of Christie’s two most prominent detectives, either a professional Belgian detective Hercule Poirot or a white-haired old lady Jane Marple. Due to their different lifestyles, both their characters and investigation methods largely differ, but they are both successful when tackling a crime. This paper attempts to offer deeper insight into some of the murder methods Christie resorted to in her oeuvre while simultaneously depicting the strategies Monsieur Poirot and Miss Marple employ solving murders. Consequently, the two detectives will be compared based on their crime-solving approach, as well as their overall personas.

Nicotinamide adenine dinucleotide (NAD+) metabolism is deregulated in cancer. Nicotinamide N-methyltransferase (NNMT) and aldehyde oxidase (AOX1) cooperatively protect cells from the negative effect of nicotinamide (NAM) accumulation in cells and its inhibitory effect on NAD+-dependent signaling reactions. Aberrantly elevated activity of NNMT and AOX1 may, over time, cause NAD+ depletion, mediated by exclusion of NAM from the NAD+ salvage pathway. To investigate NNMT and AOX1-mediated "NAM drain", various cancer cell lines were first tested for the expression of these two enzymes. Cell lines HT-29, Cal27, Detroit 562 and MDA-MB-231 were found to simultaneously express different levels of NNMT and AOX1 and were chosen for interrogation of the effect of raloxifene hydrochloride, a potent AOX1 inhibitor, on cellular NAD+ level. Tested cell lines differed in their basal cellular NAD+ level. Upon treatment with raloxifene hydrochloride, NAD+ level increased in all tested cell lines, but the extent of the increase was cell-type specific. Unexpectedly, dimethyl sulphoxide (DMSO) in concentration of 0.05%, used as raloxifene hydrochloride solvent, had profound negative effect on NAD+ level in HT-29, Cal27 and MDA-MB-231, but not Detroit 562 cells. The presented results warrant detailed further exploration of cell-type specific potency of raloxifene hydrochloride in restoring cellular NAD+ levels and the extent to which DMSO is blunting this effect in cell culture models.