Rebekah I. Dawson, Chelsea X. Huang, Rafael Brahm, Karen A. Collins, Melissa J. Hobson, Andrés Jordán, Jiayin Dong, Judith Korth, Trifon Trifonov, Lyu Abe, Abdelkrim Agabi, Ivan Bruni, R. Paul Butler, Mauro Barbieri, Kevin I. Collins, Dennis M. Conti, Jeffrey D. Crane, Nicolas Crouzet, Georgina Dransfield, Phil Evans, Néstor Espinoza, Tianjun Gan, Tristan Guillot, Thomas Henning, Jack J. Lissauer, Eric L. N. Jensen, Wenceslas Marie Sainte, Djamel Mékarnia, Gordon Myers, Sangeetha Nandakumar, Howard M. Relles, Paula Sarkis, Pascal Torres, Stephen Shectman, François-Xavier Schmider, Avi Shporer, Chris Stockdale, Johanna Teske, Amaury H. M. J. Triaud, Sharon Xuesong Wang, Carl Ziegler, G. Ricker, R. Vanderspek, David W. Latham, S. Seager, J. Winn, Jon M. Jenkins, L. G. Bouma, Jennifer A. Burt, David Charbonneau, Alan M. Levine, Scott McDermott, Brian McLean, Mark E. Rose, Andrew Vanderburg, Bill Wohler. (2021). Precise Transit and Radial-velocity Characterization of a Resonant Pair: The Warm Jupiter TOI-216c and Eccentric Warm Neptune TOI-216b (Vol. 161).
Abstract: TOI-216 hosts a pair of warm, large exoplanets discovered by the TESS mission. These planets were found to be in or near the 2:1 resonance, and both of them exhibit transit timing variations (TTVs). Precise characterization of the planets’ masses and radii, orbital properties, and resonant behavior can test theories for the origins of planets orbiting close to their stars. Previous characterization of the system using the first six sectors of TESS data suffered from a degeneracy between planet mass and orbital eccentricity. Radial-velocity measurements using HARPS, FEROS, and the Planet Finder Spectrograph break that degeneracy, and an expanded TTV baseline from TESS and an ongoing ground-based transit observing campaign increase the precision of the mass and eccentricity measurements. We determine that TOI-216c is a warm Jupiter, TOI-216b is an eccentric warm Neptune, and that they librate in 2:1 resonance with a moderate libration amplitude of deg, a small but significant free eccentricity of for TOI-216b, and a small but significant mutual inclination of 1.°2–3.°9 (95% confidence interval). The libration amplitude, free eccentricity, and mutual inclination imply a disturbance of TOI-216b before or after resonance capture, perhaps by an undetected third planet.
Programme: 1066
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M. A. Kenworthy, S. N. Mellon, J. I. Bailey, R. Stuik, P. Dorval, G. J. J. Talens, S. R. Crawford, E. E. Mamajek, I. Laginja, M. Ireland, B. Lomberg, R. B. Kuhn, I. Snellen, K. Zwintz, R. Kuschnig, G. M. Kennedy, L. Abe, A. Agabi, D. Mekarnia, T. Guillot, F. Schmider, P. Stee, Y. de Pra, M. Buttu, N. Crouzet, P. Kalas, J. J. Wang, K. Stevenson, E. de Mooij, A.-M. Lagrange, S. Lacour, A. Lecavelier des Etangs, M. Nowak, P. A. Strøm, Z. Hui, L. Wang. (2021). The β Pictoris b Hill sphere transit campaign – I. Photometric limits to dust and rings (Vol. 648).
Abstract: Aims. Photometric monitoring of β Pic in 1981 showed anomalous fluctuations of up to 4% over several days, consistent with foreground material transiting the stellar disk. The subsequent discovery of the gas giant planet β Pic b and the predicted transit of its Hill sphere to within a 0.1 au projected separation of the planet provided an opportunity to search for the transit of a circumplanetary disk (CPD) in this 21 ± 4 Myr-old planetary system. We aim to detect, or put an upper limit on, the density and nature of the material in the circumplanetary environment of the planet via the continuous photometric monitoring of the Hill sphere transit that occurred in 2017 and 2018.Methods. Continuous broadband photometric monitoring of β Pic requires ground-based observatories at multiple longitudes to provide redundancy and to provide triggers for rapid spectroscopic follow-up. These include the dedicated β Pic monitoring bRing observatories in Sutherland and Siding Springs, the ASTEP400 telescope at Concordia, and the space observatories BRITE and the Hubble Space Telescope (HST). We search the combined light curves for evidence of short-period transient events caused by rings as well as for longer-term photometric variability due to diffuse circumplanetary material.Results. We find no photometric event that matches with the event seen in November 1981, and there is no systematic photometric dimming of the star as a function of the Hill sphere radius.Conclusions. We conclude that the 1981 event was not caused by the transit of a CPD around β Pic b. The upper limit on the long-term variability of β Pic places an upper limit of 1.8 × 1022 g of dust within the Hill sphere (comparable to the ~100 km radius asteroid 16 Psyche). Circumplanetary material is either condensed into a disk that does not transit β Pic, condensed into a disk with moons that has an obliquity that does not intersect with the path of β Pic behind the Hill sphere, or is below our detection threshold. This is the first time that a dedicated international campaign has mapped the Hill sphere transit of an extrasolar gas giant planet at 10 au.
Programme: 1066
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Jennifer A. Burt, Diana Dragomir, Paul Mollière, Allison Youngblood, Antonio García Muñoz, John McCann, Laura Kreidberg, Chelsea X. Huang, Karen A. Collins, Jason D. Eastman, Lyu Abe, Jose M. Almenara, Ian J. M. Crossfield, Carl Ziegler, Joseph E. Rodriguez, Eric E. Mamajek, Keivan G. Stassun, Samuel P. Halverson, Steven Villanueva, R. Paul Butler, Sharon Xuesong Wang, Richard P. Schwarz, George R. Ricker, Roland Vanderspek, David W. Latham, S. Seager, Joshua N. Winn, Jon M. Jenkins, Abdelkrim Agabi, Xavier Bonfils, David Ciardi, Marion Cointepas, Jeffrey D. Crane, Nicolas Crouzet, Georgina Dransfield, Fabo Feng, Elise Furlan, Tristan Guillot, Arvind F. Gupta, Steve B. Howell, Eric L. N. Jensen, Nicholas Law, Andrew W. Mann, Wenceslas Marie-Sainte, Rachel A. Matson, Elisabeth C. Matthews, Djamel Mékarnia, Joshua Pepper, Nic Scott, Stephen A. Shectman, Joshua E. Schlieder, François-Xavier Schmider, Daniel J. Stevens, Johanna K. Teske, Amaury H. M. J. Triaud, David Charbonneau, Zachory K. Berta-Thompson, Christopher J. Burke, Tansu Daylan, Thomas Barclay, Bill Wohler, C. E. Brasseur. (2021). TOI-1231 b: A Temperate, Neptune-sized Planet Transiting the Nearby M3 Dwarf NLTT 24399 (Vol. 162).
Abstract: We report the discovery of a transiting, temperate, Neptune-sized exoplanet orbiting the nearby (d = 27.5 pc), M3V star TOI-1231 (NLTT 24399, L 248-27, 2MASS J10265947-5228099). The planet was detected using photometric data from the Transiting Exoplanet Survey Satellite and followed up with observations from the Las Cumbres Observatory and the Antarctica Search for Transiting ExoPlanets program. Combining the photometric data sets, we find that the newly discovered planet has a radius of and an orbital period of 24.246 days. Radial velocity measurements obtained with the Planet Finder Spectrograph on the Magellan Clay telescope confirm the existence of the planet and lead to a mass measurement of 15.5 ± 3.3 M ⊕. With an equilibrium temperature of just 330 K, TOI-1231 b is one of the coolest small planets accessible for atmospheric studies thus far, and its host star’s bright near-infrared brightness (J = 8.88, K s = 8.07) makes it an exciting target for the Hubble Space Telescope and the James Webb Space Telescope. Future atmospheric observations would enable the first comparative planetology efforts in the 250–350 K temperature regime via comparisons with K2-18 b. Furthermore, TOI-1231's high systemic radial velocity (70.5 km s−1) may allow for the detection of low-velocity hydrogen atoms escaping the planet by Doppler, shifting the H i Lyα stellar emission away from the geocoronal and interstellar medium absorption features.
Programme: 1066
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Yves Cherel. (2021). ?Mastigoteuthis B Clarke, 1980, is a junior synonym of Asperoteuthis acanthoderma (Lu, 1977) (Cephalopoda, Oegopsida, Chiroteuthidae), a rare cosmopolitan deep-sea squid (Vol. 51).
Abstract: The present work resolved the long-standing taxonomic problem associated with the enigmatic ?Mastigoteuthis B Clarke, 1980, by demonstrating that these lower beaks correspond to those of the large deep-sea chiroteuthid Asperoteuthis acanthoderma (Lu, 1977). A review of the existing literature listed 22 specimens of A. acanthoderma, but synonymizing ?Mastigoteuthis B with A. acanthoderma increased 14 times the species record worldwide. Pooling the data from both specimens and beaks (a total of 329 individuals) indicates that the species has a circumglobal distribution, since it occurs in tropical and subtropical waters of the Atlantic, Indian and Pacific Oceans. The synonymization also highlights trophic relationships of the species as a prey of top marine predators. Lower beaks of A. acanthoderma were mostly found in stomachs of sperm whales, but a few beaks were also recorded from stomach contents of sharks, swordfish and the wandering albatross.
Programme: 109
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Jilda Alicia Caccavo, Thierry Raclot, Timothée Poupart, Yan Ropert-Coudert, Frédéric Angelier. (2021). Anthropogenic activities are associated with shorter telomeres in chicks of Adélie penguin (Pygoscelis adeliae) (Vol. 44).
Abstract: Defining the impact of anthropogenic stressors on Antarctic wildlife is an active aim for investigators. Telomeres represent a promising molecular tool to investigate the fitness of wild populations, as their length may predict longevity and survival. We examined the relationship between telomere length and human exposure in Adélie penguin chicks (Pygoscelis adeliae) from East Antarctica. Telomere length was compared between chicks from areas with sustained human activity and on neighboring protected islands with little or no human presence. Adélie penguin chicks from sites exposed to human activity had significantly shorter telomeres than chicks from unexposed sites in nearby protected areas, with exposed chicks having on average 3.5% shorter telomeres than unexposed chicks. While sampling limitations preclude our ability to draw more sweeping conclusions at this time, our analysis nonetheless provides important insights into measures of colony vulnerability. More data are needed both to understand the proximate causes (e.g., stress, feeding events) leading to shorter telomeres in chicks from human exposed areas, as well as the fitness consequences of reduced telomere length. We suggest to further test the use of telomere length analysis as an eco-indicator of stress in wildlife among anthropized sites throughout Antarctica.
Programme: 1091
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Chiara Papetti, Massimiliano Babbucci, Agnes Dettai, Andrea Basso, Magnus Lucassen, Lars Harms, Celine Bonillo, Franz Maximilian Heindler, Tomaso Patarnello, Enrico Negrisolo. (2021). Not Frozen in the Ice: Large and Dynamic Rearrangements in the Mitochondrial Genomes of the Antarctic Fish (Vol. 13).
Abstract: The vertebrate mitochondrial genomes generally present a typical gene order. Exceptions are uncommon and important to study the genetic mechanisms of gene order rearrangements and their consequences on phylogenetic output and mitochondrial function. Antarctic notothenioid fish carry some peculiar rearrangements of the mitochondrial gene order. In this first systematic study of 28 species, we analyzed known and undescribed mitochondrial genome rearrangements for a total of eight different gene orders within the notothenioid fish. Our reconstructions suggest that transpositions, duplications, and inversion of multiple genes are the most likely mechanisms of rearrangement in notothenioid mitochondrial genomes. In Trematominae, we documented an extremely rare inversion of a large genomic segment of 5,300 bp that partially affected the gene compositional bias but not the phylogenetic output. The genomic region delimited by nad5 and trnF, close to the area of the Control Region, was identified as the hot spot of variation in Antarctic fish mitochondrial genomes. Analyzing the sequence of several intergenic spacers and mapping the arrangements on a newly generated phylogeny showed that the entire history of the Antarctic notothenioids is characterized by multiple, relatively rapid, events of disruption of the gene order. We hypothesized that a pre-existing genomic flexibility of the ancestor of the Antarctic notothenioids may have generated a precondition for gene order rearrangement, and the pressure of purifying selection could have worked for a rapid restoration of the mitochondrial functionality and compactness after each event of rearrangement.
Programme: 1124
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Karl-Ludwig Klein. (2021). Radio Astronomical Tools for the Study of Solar Energetic Particles I. Correlations and Diagnostics of Impulsive Acceleration and Particle Propagation (Vol. 7).
Abstract: Solar energetic particles (SEPs) are sporadically ejected from the Sun during flares and coronal mass ejections. They are of major astrophysical interest, because the proximity of the Sun allows for detailed multi-messenger studies. They affect space weather due to interactions with electronics, with the Earth’s atmosphere, and with humans if they leave the protective shield of the magnetosphere of the Earth. Since early studies in the 1950s, starting with particle detectors on the ground, SEP events have been related to radio bursts. Two subjects are addressed in this chapter: attempts to establish quantitative correlations between SEPs and microwave bursts produced by gyro synchrotron radiation of mildly relativistic electrons, and the information derived from type III radio bursts on impulsive processes of particle acceleration and the coronal and interplanetary propagation. Type III radio bursts produced by electron beams on open magnetic field lines have a wide range of applications, including the identification of acceleration regions, the identification of confined particle acceleration with coronal signatures, but no SEPs, and the paths that the electrons, and energetic charged particles in general, take to travel from the low corona to the Heliosphere in case they escape. Simple scenarios of coronal particle acceleration are confirmed in relatively simple and short events. But the comparison with particle transport models shows that longer and delayed acceleration episodes exist especially in large SEP events. They will be discussed in a companion chapter.
Programme: 227
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Anika Immer, Thomas Merkling, Olivier Chastel, Scott A. Hatch, Etienne Danchin, Pierrick Blanchard, Sarah Leclaire. (2021). Spying on your neighbours? Social information affects timing of breeding and stress hormone levels in a colonial seabird (Vol. 35).
Abstract: A good overlap between offspring energetic requirements and availability of resources is required for successful reproduction. Accordingly, individuals from numerous species fine-tune their timing of breeding by integrating cues that predict environmental conditions during the offspring period. Besides acquiring information from their direct interaction with the environment (personal information), individuals can integrate information by observing the behaviours or performance of others (social information). The use of social information is often beneficial because the accumulated knowledge of conspecifics may represent a source of information more reliable than the intrinsically more limited personal information. However, although social information constitutes the major source of information in a wide range of contexts, studies investigating its use in the context of timing of breeding are scarce. We investigated whether black-legged kittiwakes (Rissa tridactyla) used social information to adjust the timing of egg-laying. We manipulated social information using a food-supplementation experiment, known to advance kittiwakes' reproductive phenology. We expected food-supplemented and unsupplemented pairs to delay and advance, respectively, their timing of laying when surrounded by a majority of neighbours from the opposite food-treatment. However, both unsupplemented and food-supplemented kittiwakes delayed egg-laying when surrounded by a higher proportion of neighbours from the opposite food-treatment. This result shows that kittiwakes use social information to time egg-laying, but that it is not used to match the seasonal peak of food availability. We suggest that when social and personal cues give contradictory environmental information, individuals may benefit from delaying laying to gather more information to make better decisions about investment into eggs. Further, we explored a potential proximate mechanism for the pattern we report. We show that baseline corticosterone, known to mediate reproductive decisions, was lower in unsupplemented females facing a higher proportion of food-supplemented neighbours. Altogether, our results suggest that to fine-tune their timing of laying, kittiwakes use complex decision-making processes in which social and personal information interplay.
Programme: 1162
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Jesús A Ballesteros, Emily V W Setton, Carlos E Santibáñez-López, Claudia P Arango, Georg Brenneis, Saskia Brix, Kevin F Corbett, Esperanza Cano-Sánchez, Merai Dandouch, Geoffrey F Dilly, Marc P Eleaume, Guilherme Gainett, Cyril Gallut, Sean McAtee, Lauren McIntyre, Amy L Moran, Randy Moran, Pablo J López-González, Gerhard Scholtz, Clay Williamson, H Arthur Woods, Jakob T Zehms, Ward C Wheeler, Prashant P Sharma. (2021). Phylogenomic Resolution of Sea Spider Diversification through Integration of Multiple Data Classes (Vol. 38).
Abstract: Despite significant advances in invertebrate phylogenomics over the past decade, the higher-level phylogeny of Pycnogonida (sea spiders) remains elusive. Due to the inaccessibility of some small-bodied lineages, few phylogenetic studies have sampled all sea spider families. Previous efforts based on a handful of genes have yielded unstable tree topologies. Here, we inferred the relationships of 89 sea spider species using targeted capture of the mitochondrial genome, 56 conserved exons, 101 ultraconserved elements, and 3 nuclear ribosomal genes. We inferred molecular divergence times by integrating morphological data for fossil species to calibrate 15 nodes in the arthropod tree of life. This integration of data classes resolved the basal topology of sea spiders with high support. The enigmatic family Austrodecidae was resolved as the sister group to the remaining Pycnogonida and the small-bodied family Rhynchothoracidae as the sister group of the robust-bodied family Pycnogonidae. Molecular divergence time estimation recovered a basal divergence of crown group sea spiders in the Ordovician. Comparison of diversification dynamics with other marine invertebrate taxa that originated in the Paleozoic suggests that sea spiders and some crustacean groups exhibit resilience to mass extinction episodes, relative to mollusk and echinoderm lineages.
Programme: 1124
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Noor Johnson, Matthew L Druckenmiller, Finn Danielsen, Peter L Pulsifer. (2021). The Use of Digital Platforms for Community-Based Monitoring (Vol. 71). Bachelor's thesis, , .
Abstract: Environmental observing programs that are based on Indigenous and local knowledge increasingly use digital technologies. Digital platforms may improve data management in community-based monitoring (CBM) programs, but little is known about how their use translates into tangible results. Drawing on published literature and a survey of 18 platforms, we examine why and how digital platforms are used in CBM programs and illuminate potential challenges and opportunities. Digital platforms make it easy to collect, archive, and share CBM data, facilitate data use, and support understanding larger-scale environmental patterns through interlinking with other platforms. Digital platforms, however, also introduce new challenges, with implications for the sustainability of CBM programs and communities’ abilities to maintain control of their own data. We expect that increased data access and strengthened technical capacity will create further demand within many communities for ethically developed platforms that aid in both local and larger-scale decision-making.
Programme: 1090,1206
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