239 research outputs found
Effect of 2,4-dichlorophenoxyacetic acid on rat maternal behavior
No full textExposure to 2,4-dichlorophenoxyacetic acid (2,4-D) has several deleterious effects on the nervous system such as alterations in the concentrations of neurotransmitters in the brain and/or behavioral changes, myelination rate, ganglioside pattern [Bortolozzi, A., Duffard, R., Antonelli, M., Evangelista de Duffard, A.M., 2002. Increased sensitivity in dopamine D(2)-like brain receptors from 2,4-dichlorophenoxyacetic acid (2,4-D)-exposed and amphetamine-challenged rats. Ann. N.Y. Acad. Sci. 965, 314-323; Duffard, R., García, G., Rosso, S., Bortolozzi, A., Madariaga, M., DiPaolo, O., Evangelista de Duffard, A.M., 1996. Central nervous system myelin deficit in rats exposed to 2,4-dichlorophenoxyacetic acid throughout lactation. Neurotoxicol. Teratol. 18, 691-696; Evangelista de Duffard, A.M., Orta, C., Duffard, R., 1990. Behavioral changes in rats fed a diet containing 2,4-dichlorophenoxyacetic butyl ester. Neurotoxicology 11, 563-572; Evangelista de Duffard, A.M., Bortolozzi, A., Duffard, R.O., 1995. Altered behavioral responses in 2,4-dichlorophenoxyacetic acid treated and amphetamine challenged rats. Neurotoxicology 16, 479-488; Munro, I.C., Carlo, G.L., Orr, J.C., Sund, K., Wilson, R.M. Kennepohl, E. Lynch, B., Jablinske, M., Lee, N., 1992. A comprehensive, integrated review and evaluation of the scientific evidence relating to the safety of the herbicide 2,4-D. J. Am. Coll. Toxicol. 11, 559-664; Rosso et al., 2000], and its administration to pregnant and lactating rats adversely affects litter growth and milk quality. Since normal growth of the offspring depends on adequate maternal nursing and care, we evaluated the effect of 2,4-D on rat maternal behavior as well as the dam's monoamine levels in arcuate nucleus (AcN) and serum prolactin (PRL) levels. Wistar dams were exposed to the herbicide through the food from post partum day (PPD) 1 to PPD 7. Dams were fed either with a 2,4-D treated diet (15, 25 or 50 mg 2,4-D/kg/day bw) or with a control diet. We observed that maternal nesting behavior was not modified by 2,4-D treatment. However, mother-pup interactions, specially the nursing behavior, were altered. Retrieval, crouching and licking of pups were reduced or suspended after 2,4-D treatment. We also observed an increase in the latency of retrieval and crouching in the dams treated with the herbicide. Dams showed movement along cage peripheries, food consumption during the light phase and high self-grooming. In addition of the deficits observed in maternal behavior parameters, increased catecholamine levels and a drastic decrease in indolamine levels in the AcN of treated dams were determined. Serum PRL levels were also diminished by 62%, 68% and 70% with respect to control dams in the 15, 25 and 50 mg 2,4-D/kg bw treated dams, respectively. In conclusion, exposure to 2,4-D during the first post partum days produced changes in maternal behavior, serum prolactin and monoamine levels in the AcN of treated dams.Fil: Stürtz, Nelson. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Laboratorio de Toxicología Experimental; ArgentinaFil: Deis, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Jahn, Graciela Alma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Laboratorio de Toxicología Experimental; ArgentinaFil: Duffard, Ricardo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Laboratorio de Toxicología Experimental; ArgentinaFil: Evangelista de Duffard, Ana Maria. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Laboratorio de Toxicología Experimental; Argentin
Status of the STUDIO UV balloon mission and platform
No full textGround-Based and Airborne Telescopes VIII 2020; Virtual, Online; United States; 14 December 2020 through 22 December 2020; Code 166573.--Proceedings of SPIE - The International Society for Optical Engineering
Volume 11445, 2020, Article number 114451Y.--Full list of authors: Pahler, A.; Ã ngermann, M.; Barnstedt, J.; Bougueroua, S.; Colin, A.; Conti, L.; Diebold, S.; Duffard, R.; Emberger, M.; Hanke, L.; Kalkuhl, C.; Kappelmann, N.; Keilig, T.; Klinkner, S.; Krabbe, A.; Janson, O.; Lengowski, M.; Lockowandt, C.; Maier, P.; Müller, T.; Rauch, T.; Schanz, T.; Stelzer, B.; Taheran, M.; Vaerneus, A.; Werner, K.; Wolf, J.Stratospheric balloons offer accessible and affordable platforms for observations in atmosphere-constrained wavelength ranges. At the same time, they can serve as an effective step for technology demonstration towards future space applications of instruments and other hardware. The Stratospheric UV Demonstrator of an Imaging Observatory (STUDIO) is a balloon-borne platform and mission carrying an imaging micro-channel plate (MCP) detector on a 0.5 m aperture telescope. STUDIO is currently planned to fly during the summer turnaround conditions over Esrange, Sweden, in the 2022 season. For details on the ultraviolet (UV) detector, see the contribution of Conti et al. to this symposium.1 The scientific goal of the mission is to survey for variable hot compact stars and flaring M-dwarf stars within the galactic plane. At the same time, the mission acts as a demonstrator for a versatile and scalable astronomical balloon platform as well as for the aforementioned MCP instrument. The gondola is designed to allow the use of different instruments or telescopes. Furthermore, it is designed to serve for several, also longer flights, which are envisioned under the European Stratospheric Balloon Observatory (ESBO) initiative. In this paper, we present the design and current status of manufacturing and testing of the STUDIO platform. We furthermore present the current plans for the flight and observations from Esrange. © COPYRIGHT SPIE.ESBO DS has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 777516. R. Duffard and A. Colin acknowledge financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de Andalucía ?SEV-2017-0709)
Study of the Plutino Object (208996) 2003 AZ84 from Stellar Occultations: Size, Shape, and Topographic Features
No full textDias-Oliveira, A. et al.-- Full list of authors: Dias-Oliveira, A.; Sicardy, B.; Ortiz, J. L.; Braga-Ribas, F.; Leiva, R.; Vieira-Martins, R.; Benedetti-Rossi, G.; Camargo, J. I. B.; Assafin, M.; Gomes-Júnior, A. R.; Baug, T.; Chandrasekhar, T.; Desmars, J.; Duffard, R.; Santos-Sanz, P.; Ergang, Z.; Ganesh, S.; Ikari, Y.; Irawati, P.; Jain, J.; Liying, Z.; Richichi, A.; Shengbang, Q.; Behrend, R.; Benkhaldoun, Z.; Brosch, N.; Daassou, A.; Frappa, E.; Gal-Yam, A.; Garcia-Lozano, R.; Gillon, M.; Jehin, E.; Kaspi, S.; Klotz, A.; Lecacheux, J.; Mahasena, P.; Manfroid, J.; Manulis, I.; Maury, A.; Mohan, V.; Morales, N.; Ofek, E.; Rinner, C.; Sharma, A.; Sposetti, S.; Tanga, P.; Thirouin, A.; Vachier, F.; Widemann, T.; Asai, A.; Hayato, Watanabe; Hiroyuki, Watanabe; Owada, M.; Yamamura, H.; Hayamizu, T.; Bradshaw, J.; Kerr, S.; Tomioka, H.; Andersson, S.; Dangl, G.; Haymes, T.; Naves, R.; Wortmann, G.We present results derived from four stellar occultations by the plutino object (208996) 2003 AZ, detected on 2011 January 8 (single-chord event), 2012 February 3 (multi-chord), 2013 December 2 (single-chord), and 2014 November 15 (multi-chord). Our observations rule out an oblate spheroid solution for 2003 AZ's shape. Instead, assuming hydrostatic equilibrium, we find that a Jacobi triaxial solution with semiaxes km can better account for all our occultation observations. Combining these dimensions with the rotation period of the body (6.75 hr) and the amplitude of its rotation light curve, we derive a density g cm, a geometric albedo . A grazing chord observed during the 2014 occultation reveals a topographic feature along 2003 AZ's limb, which can be interpreted as an abrupt chasm of width ∼23 km and depth km, or a smooth depression of width ∼80 km and depth ∼13 km (or an intermediate feature between those two extremes). © 2017. The American Astronomical SocietyWe acknowledge support from the French grants "Beyond Neptune" ANR-08-BLAN-0177 and "Beyond Neptune II" ANR-11-IS56-0002. Part of the research leading to these results has received funding from the European Research Council under the European Community's H2020 (2014-2020/ERC Grant Agreement no. 669416 "LUCKY STAR"). A. Dias-Oliveira thanks the support of the following grants: CAPES (BEX 9110/12-7) FAPERJ/PAPDRJ (E-45/2013). R. Leiva acknowledges support from CONICYT-PCHA/Doctorado Nacional/2014-21141198. R. Duffard, J.L. Ortiz, and P. Santos-Sanz have received funding from the European Union's Horizon 2020 Research and Innovation Programme, under Grant Agreement no. 687378. R. Vieira-Martins thanks the following grants: CNPq-306885/2013, Capes/Cofecub-2506/2015, Faperj: PAPDRJ-45/2013 and E-26/203.026/2015. M. Assafin thanks the CNPq (Grants 473002/2013-2 and 308721/2011-0) and FAPERJ (Grant E-26/111.488/2013). J.I.B. Camargo acknowledges a CNPq/PQ2 fellowship 308489/2013-6. This work has made use of data obtained at the Thai National Observatory on Doi Inthanon, operated by NARIT. A. Maury acknowledges the use of the C. Harlingten telescope of the Searchlight Observatory Network Funding from Spanish grant AYA-2014-56637-C2-1-P is acknowledged, as is the Proyecto de Excelencia de la Junta de Andaluca, JA 2012-FQM1776. A. Thirouin acknowledges funding from Lowell Observatory. G.B.R. is thankful for the support of the CAPES (203.173/2016) and FAPERJ/PAPDRJ (E26/200.464/2015-227833) grants
GAUSS - genesis of asteroids and evolution of the solar system
No full textThe goal of Project GAUSS (Genesis of Asteroids and evolUtion of the Solar System) is to return samples from the dwarf planet Ceres. Ceres is the most accessible candidate of ocean worlds and the largest reservoir of water in the inner Solar System. It shows active volcanism and hydrothermal activities in recent history. Recent evidence for the existence of a subsurface ocean on Ceres and the complex geochemistry suggest past habitability and even the potential for ongoing habitability. GAUSS will return samples from Ceres with the aim of answering the following top-level scientific questions: - What is the origin of Ceres and what does this imply for the origin of water and other volatiles in the inner Solar System? - What are the physical properties and internal structure of Ceres? What do they tell us about the evolutionary and aqueous alteration history of dwarf planets? - What are the astrobiological implications of Ceres? Is it still habitable today? - What are the mineralogical connections between Ceres and our current collections of carbonaceous meteorites?Part of this work has been carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). J.-Y.L. acknowledges partial support from the Solar System Exploration Research Virtual Institute 2016 (SSERVI16) Cooperative Agreement (grant NNH16ZDA001N), SSERVI-TREX to the Planetary Science Institute. J.A. acknowledges support from the European Research Council Starting Grant 757390 (CAstRA). A.J.C. and G.H.J. acknowledge support from the STFC consolidated grant to UCL-MSSL STS0002401. P. Santos-Sanz, and R. Duffard acknowledges financial support by the Spanish grant AYA- RTI2018-098657-J-I00 ’LEO-SBNAF’ (MCIU/AEI/FEDER, UE). J.L. Ortiz, P. Santos-Sanz, and R. Duffard acknowledge financial support from the State Agency for Research of the Spanish MCIU through the ’Center of Excellence Severo Ochoa’ award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709). J.M.T-R. acknowledges support from the Spanish Ministry of Science and Innovation (project PGC2018-097374-B-I00). J.M.T-R.’s research has been funded by the research project (PGC2018-097374-B-I00), funded by FEDER/Ministerio de Ciencia e Innovación – Agencia Estatal de Investigación
A dense ring of the trans-Neptunian object Quaoar outside its Roche limit
No full textMorgado, B. E. et al.--Full list of authors: Morgado, B. E.; Sicardy, B.; Braga-Ribas, F.; Ortiz, J. L.; Salo, H.; Vachier, F.; Desmars, J.; Pereira, C. L.; Santos-Sanz, P.; Sfair, R.; de Santana, T.; Assafin, M.; Vieira-Martins, R.; Gomes-Junior, A. R.; Margoti, G.; Dhillon, V. S.; Fernandez-Valenzuela, E.; Broughton, J.; Bradshaw, J.; Langersek, R.; Benedetti-Rossi, G.; Souami, D.; Holler, B. J.; Kretlow, M.; Boufleur, R. C.; Camargo, J. I. B.; Duffard, R.; Beisker, W.; Morales, N.; Lecacheux, J.; Rommel, F. L.; Herald, D.; Benz, W.; Jehin, E.; Jankowsky, F.; Marsh, T. R.; Littlefair, S. P.; Bruno, G.; Pagano, I.; Brandeker, A.; Collier-Cameron, A.; Floren, H. G.; Hara, N.; Olofsson, G.; Wilson, T. G.; Benkhaldoun, Z.; Busuttil, R.; Burdanov, A.; Ferrais, M.; Gault, D.; Gillon, M.; Hanna, W.; Kerr, S.; Kolb, U.; Nosworthy, P.; Sebastian, D.; Snodgrass, C.; Teng, J. P.; de Wit, J.Planetary rings are observed not only around giant planets1, but also around small bodies such as the Centaur Chariklo2 and the dwarf planet Haumea3. Up to now, all known dense rings were located close enough to their parent bodies, being inside the Roche limit, where tidal forces prevent material with reasonable densities from aggregating into a satellite. Here we report observations of an inhomogeneous ring around the trans-Neptunian body (50000) Quaoar. This trans-Neptunian object has an estimated radius4 of 555 km and possesses a roughly 80-km satellite5 (Weywot) that orbits at 24 Quaoar radii6,7. The detected ring orbits at 7.4 radii from the central body, which is well outside Quaoar’s classical Roche limit, thus indicating that this limit does not always determine where ring material can survive. Our local collisional simulations show that elastic collisions, based on laboratory experiments8, can maintain a ring far away from the body. Moreover, Quaoar’s ring orbits close to the 1/3 spin–orbit resonance9 with Quaoar, a property shared by Chariklo’s2,10,11 and Haumea’s3 rings, suggesting that this resonance plays a key role in ring confinement for small bodies. © 2023, The Author(s), under exclusive licence to Springer Nature Limited.This work was carried out under the Lucky Star umbrella that agglomerates the efforts of the Paris, Granada and Rio teams, which is funded by the ERC under the European Community’s H2020 (ERC grant agreement no. 669416). Part of the results were obtained using CHEOPS data. CHEOPS is an ESA mission in partnership with Switzerland with important contributions to the payload and the ground segment from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden and the UK. The CHEOPS Consortium gratefully acknowledge the support received by all the agencies, offices, universities and industries involved. Their flexibility and willingness to explore new approaches were essential to the success of this mission. The design and construction of HiPERCAM was supported by the ERC under the European Union’s Seventh Framework Programme (FP/2007-2013) under ERC-2013-ADG grant agreement no. 340040 (HiPERCAM). HiPERCAM operations and V.S.D. are funded by the Science and Technology Facilities Council (grant no. ST/V000853/1). The GTC is installed at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, on the island of La Palma. This work has made use of data from the ESA mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). This study was financed in part by the National Institute of Science and Technology of the e-Universe project (INCT do e-Universo, CNPq grant no. 465376/2014-2). This study was financed in part by CAPES - Finance Code 001. The following authors acknowledge the respective (1) CNPq grants to B.E.M. no. 150612/2020-6; F.B.-R. no. 314772/2020-0; R.V.-M. no. 307368/2021-1; M.A. nos. 427700/2018-3, 310683/2017-3 and 473002/2013-2; and J.I.B.C. nos. 308150/2016-3 and 305917/2019-6. (2) CAPES/Cofecub grant to B.E.M. no. 394/2016-05. (3) FAPERJ grant no. M.A. E-26/111.488/2013. (4) FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo) grants to A.R.G.-J. no. 2018/11239-8 and R.S. no. 2016/24561-0. (5) CAPES-PrInt Program grant to G.B.-R. no. 88887.310463/2018-00, mobility number 88887.571156/2020-00. (6) DFG (the German Research Foundation) grant to R.S. no. 446102036. P.S-S. and R.D. acknowledge financial support by the Spanish grant no. AYA-RTI2018-098657-J-I00 ‘LEO-SBNAF’ (MCIU/AEI/FEDER, UE). J.L.O., P.S-S., R.D. and N.M. acknowledge financial support from the State Agency for Research of the Spanish MCIU through the ‘Center of Excellence Severo Ochoa’ award for the Instituto de Astrofísica de Andalucía (grant no. SEV-2017-0709), and they also acknowledge the financial support by the Spanish grant nos. AYA-2017-84637-R and PID2020-112789GB-I00, and the Proyectos de Excelencia de la Junta de Andalucía grant nos. 2012-FQM1776 and PY20-01309. G.B-R. and I.P. acknowledge support from CHEOPS ASI-INAF agreement no. 2019-29-HH.0. A.B. was supported by the SNSA. A.C.-C. and T.G.W. acknowledge support from STFC consolidated grant nos. ST/R000824/1 and ST/V000861/1, and UK Space Agency grant no. ST/R003203/1. U.K. and R.B. acknowledge support by The OpenSTEM Laboratories, an initiative funded by the Higher Education Funding Council for England and the Wolfson Foundation. J.W. gratefully acknowledges financial support from the Heising-Simons Foundation, C. Masson and P. A. Gilman for Artemis, the first telescope of the SPECULOOS network situated in Tenerife, Spain. The ULiege’s contribution to SPECULOOS has received funding from the ERC under the European Union’s Seventh Framework Programme (FP/2007-2013) (grant agreement no. 336480/SPECULOOS), from the Balzan Prize and Francqui Foundations, from the Belgian Scientific Research Foundation (F.R.S.-FNRS; grant no. T.0109.20), from the University of Liege and from the ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. TRAPPIST is a project funded by the Belgian Fonds (National) de la Recherche Scientique (F.R.S.-FNRS) under grant no. PDR T.0120.21. TRAPPIST-North is a project funded by the University of Liege, in collaboration with the Cadi Ayyad University of Marrakech (Morocco). E.J. is FNRS Senior Research Associate.With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (SEV-2017-0709).Peer reviewe
Pluto's Atmosphere from the 2015 June 29 Ground-based Stellar Occultation at the Time of the New Horizons Flyby
No full textSicardy, B. et al.--Full list of authors: Sicardy, B.; Talbot, J.; Meza, E.; Camargo, J. I. B.; Desmars, J.; Gault, D.; Herald, D.; Kerr, S.; Pavlov, H.; Braga-Ribas, F.; Assafin, M.; Benedetti-Rossi, G.; Dias-Oliveira, A.; Gomes-Júnior, A. R.; Vieira-Martins, R.; Bérard, D.; Kervella, P.; Lecacheux, J.; Lellouch, E.; Beisker, W.; Dunham, D.; Jelínek, M.; Duffard, R.; Ortiz, J. L.; Castro-Tirado, A. J.; Cunniffe, R.; Querel, R.; Yock, P. C.; Cole, A. A.; Giles, A. B.; Hill, K. M.; Beaulieu, J. P.; Harnisch, M.; Jansen, R.; Pennell, A.; Todd, S.; Allen, W. H.; Graham, P. B.; Loader, B.; McKay, G.; Milner, J.; Parker, S.; Barry, M. A.; Bradshaw, J.; Broughton, J.; Davis, L.; Devillepoix, H.; Drummond, J.; Field, L.; Forbes, M.; Giles, D.; Glassey, R.; Groom, R.; Hooper, D.; Horvat, R.; Hudson, G.; Idaczyk, R.; Jenke, D.; Lade, B.; Newman, J.; Nosworthy, P.; Purcell, P.; Skilton, P. F.; Streamer, M.; Unwin, M.; Watanabe, H.; White, G. L.; Watson, D.We present results from a multi-chord Pluto stellar occultation observed on 2015 June 29 from New Zealand and Australia. This occurred only two weeks before the NASA New Horizons flyby of the Pluto system and serves as a useful comparison between ground-based and space results. We find that Pluto's atmosphere is still expanding, with a significant pressure increase of 5 ± 2% since 2013 and a factor of almost three since 1988. This trend rules out, as of today, an atmospheric collapse associated with Pluto's recession from the Sun. A central flash, a rare occurrence, was observed from several sites in New Zealand. The flash shape and amplitude are compatible with a spherical and transparent atmospheric layer of roughly 3 km in thickness whose base lies at about 4 km above Pluto's surface, and where an average thermal gradient of about 5 K km prevails. We discuss the possibility that small departures between the observed and modeled flash are caused by local topographic features (mountains) along Pluto's limb that block the stellar light. Finally, using two possible temperature profiles, and extrapolating our pressure profile from our deepest accessible level down to the surface, we obtain a possible range of 11.9-13.7 μbar for the surface pressure. © 2016. The American Astronomical Society. All rights reserved.We acknowledge support from the French grant "Beyond Neptune II" ANR-11-IS56-0002, and Labex ESEP. The research leading to these results has received funding from the European Research Council under the European Community's H2020 (2014-2020/ERC Grant Agreement 669416 "LUCKY STAR"). E.M. acknowledges support from the contrato de subvención 205-2014-Fondecyt, Peru. J.I.B.C. acknowledges the CNPq/PQ2 fellowship 308489/2013-6. M.A. acknowledges the FAPERJ grant 111.488/2013, CNPq/PQ2 fellowship 312394/2014-4, and grants 482080/2009-4 and 473002/2013-2. J.L.O. acknowledges funding from Proyecto de Excelencia de la Junta de Andalucía J.A.2012-FQM1776, Spanish grant AYA-2014-56637-C2-1-P, and FEDER funds. A.J.C.T. acknowledges support from the Junta de Andalucía (Project P07-TIC-03094) and Univ. of Auckland and NIWA for installing of the Spanish BOOTES-3 station in New Zealand, and support from the Spanish Ministry Projects AYA2012-39727-C03-01 and 2015-71718R Development of the Greenhill Observatory was supported under the Australian Research Council's LIEF funding scheme (project LE110100055). We thank C. Harlingten for the use of the H127 Telescope, and D. and M. Warren for long term support. We thank L. Beauvalet for running the ODIN Pluto's system model, M. W. Buie, S. Gwyn, and L. A. Young for providing pre-event Pluto's ephemeris and astrometry, D. P. Hinson and D. F. Strobel for most useful discussions, and the reviewer for useful comments.Peer reviewe
The determination of asteroid H and G phase function parameters using Gaia DR2
No full textThe Gaia mission will provide the scientific community with high-quality observations of asteroids of all categories. The second release of Gaia data (DR2) was published in 2018 and consists of 22 months of observations of 14 099 known Solar system objects, mainly asteroids. The purpose of this work is to obtain a catalogue of phase function parameters (H and G) for all the asteroids that were observed during the Gaia mission and that were published in DR2. For this purpose, we introduce an algorithm capable of building this catalogue from the magnitude and UTC epoch data present in the DR2 data base. Because Gaia will never observe asteroids with a phase angle of 0° (corresponding to opposition), but with phase angles higher than 10°, we added data from ground observations (corresponding to small phase angles) and thus improved the determination of the H and G parameters of the phase function. We also built a catalogue of the parameters of the H, G1 andG2 phase function. We compared our results of the H, G functions with those of the Astorb data base and observed that the level of agreement is satisfactory. © 2021 The Author(s).Funding from Spanish project AYA2017-89637-R is acknowledged. Financial support was received from the State Agency for Research of the Spanish MCIU through the Center of Excellence Severo Ochoa for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). MC is a doctoral fellow of CONICET (Argentina). The resources to support astorb.dat were originally provided by NASA grant NAG5-4741 (PI E. Bowell) and the Lowell Observatory endowment, and more recently by NASA PDART grant NNX16AG52G (PI N. Moskovitz).Peer reviewe
Status, flight preparation, and future instrument opportunities of the STUDIO balloon-borne telescope platform
No full textGround-Based and Airborne Telescopes IX (2022), Montreal, Jul 17-22, 2022.--Proceedings of SPIE - The International Society for Optical Engineering vol. 12182 Article number 121822N.-- Full list of authors: Bougueroua, S.; Ångerman, M.; Barnstedt, J.; Colin, A.; Conti, L.; Diebold, S.; Duffard, R.; Janson, O.; Kalkuhl, C.; Kappelmann, N.; Keilig, T.; Klinkner, S.; Krabbe, A.; Lengowski, M.; Lockowandt, C.; Maier, P.; Müller, T.; Pahler, A.; Rauch, T.; Schanz, T.; Stelzer, B.; Taheran, M.; Vaerneus, A.; Werner, K.; Wolf, J.The Stratospheric UV Demonstrator of an Imaging Observatory (STUDIO) is a balloon-borne platform designed and built to carry different astronomical instruments or telescopes. It thereby offers an accessible and affordable platform for observations in atmosphere-constrained wavelength ranges. In its current setup, it houses an imaging micro-channel plate (MCP) detector on a 0.5 m aperture telescope. The first flight of this setup is planned during the summer turnaround conditions over Esrange, Sweden, in the 2023 or 2024 season. This mission will act as a demonstrator and technical test for the versatile and scalable astronomical platform as well as for the aforementioned MCP instrument. If successful, it will furthermore allow first scientific studies of variable hot compact stars and flaring M-dwarf stars within the galactic plane. In this paper, we present the design and current status of testing of the STUDIO platform, particularly including environmental tests of the optical elements, on-sky tests of the gondola attitude control system, and simulation results of the image stabilization system. We furthermore describe the planned system tests as part of the flight preparation. As an outlook, we present details on how the platform can be used to fly different instruments or telescopes, including potential flight routes and science opportunities. © 2022 SPIE.ESBO DS has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 777516. R. Duffard and A. Colin acknowledge financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709).Peer reviewe
Size and Shape of Chariklo from Multi-epoch Stellar Occultations
No full textLeiva, Rodrigo et al.-- Full list of authors: Leiva, R.; Sicardy, B.; Camargo, J. I. B.; Ortiz, J. -L.; Desmars, J.; Bérard, D.; Lellouch, E.; Meza, E.; Kervella, P.; Snodgrass, C.; Duffard, R.; Morales, N.; Gomes-Júnior, A. R.; Benedetti-Rossi, G.; Vieira-Martins, R.; Braga-Ribas, F.; Assafin, M.; Morgado, B. E.; Colas, F.; De Witt, C.; Sickafoose, A. A.; Breytenbach, H.; Dauvergne, J. -L.; Schoenau, P.; Maquet, L.; Bath, K. -L.; Bode, H. -J.; Cool, A.; Lade, B.; Kerr, S.; Herald, D.We use data from five stellar occultations observed between 2013 and 2016 to constrain Chariklo's size and shape, and the ring reflectivity. We consider four possible models for Chariklo (sphere, Maclaurin spheroid, triaxial ellipsoid, and Jacobi ellipsoid), and we use a Bayesian approach to estimate the corresponding parameters. The spherical model has a radius R = 129 ±3 km. The Maclaurin model has equatorial and polar radii a = b 143 km and c = 96 km, respectively, with density 970 kg m. The ellipsoidal model has semiaxes a = 148 km, b = 132 km, and a = c 102 km. Finally, the Jacobi model has semiaxes a = 157 ±4 km, b = 139 ±4 km, and c = 86 ±1 km, and density . Depending on the model, we obtain topographic features of 6-11 km, typical of Saturn icy satellites with similar size and density. We constrain Chariklo's geometric albedo between 3.1% (sphere) and 4.9% (ellipsoid), while the ring I/F reflectivity is less constrained between 0.6% (Jacobi) and 8.9% (sphere). The ellipsoid model explains both the optical light curve and the long-term photometry variation of the system, giving a plausible value for the geometric albedo of the ring particles of 10%-15%. The derived mass of Chariklo of 6-8 ×10 kg places the rings close to 3:1 resonance between the ring mean motion and Chariklo's rotation period. © 2017. The American Astronomical SocietyR.L. acknowledges support from CONICYT-PCHA/Doctorado Nacional/2014-21141198. The authors acknowledge
support from the French grant “Beyond Neptune II” ANR-11-
IS56-0002. Part of the research leading to these results has
received funding from the European Research Council under
the European Community’s H2020 (2014-2020/ERC Grant
Agreement n° 669416 “LUCKY STAR”). The research leading
to these results has received funding from the European
Union’s Horizon 2020 Research and Innovation Programme,
under Grant Agreement N°. 687378, project SBNAF. E.M.
acknowledges support from the Contrato de subvención 205-
2014 Fondecyt—Concytec, Perú. J.I.B.C. acknowledges the
CNPq grant n° 308150/2016-3. M.A. thanks the CNPq (Grants
473002/2013-2 and 308721/2011-0) and FAPERJ (Grant
E-26/111.488/2013). G.B.-R. acknowledges the support of
the CAPES (203.173/2016) and FAPERJ/PAPDRJ (E26/
200.464/2015-227833) grants. R.V.-M. thanks grants CNPq306885/2013, Capes/Cofecub-2506/2015, Faperj: PAPDRJ45/2013, and E-26/203.026/2015. This work is partly based
on observations performed at the MPG 2.2 meter telescope,
program CN2016A-87. Based on observations obtained at the
SOAR telescope, program SO2015A-015. The 50 cm telescopes used for the Hakos observations belong to the IAS
observatory at Hakos/Namibia. This work was partially
supported by the National Research Foundation of South
Africa and contains data taken at the South African
Astronomical Observatory (SAAO). This work has made use
of data from the European Space Agency (ESA) mission Gaia
(https://www.cosmos.esa.int/gaia), processed by the Gaia
Data Processing and Analysis Consortium (DPAC; https://
www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for
DPAC has been provided by national institutions, in particular
the institutions participating in the Gaia Multilateral Agreement.
Facilities: SOAR (SOI), Max Planck:2.2 m (WFI), LNA:
BC0.6m.
Software: DanDIA (Bramich 2008), IRAF (Tody 1986),
emcee (Foreman-Mackey et al. 2013)
Author Correction: A dense ring of the trans-Neptunian object Quaoar outside its Roche limit
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