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Author Addison, BC.; Wright, DJ.; Nicholson, BA.; Cale, B.; Mocnik, T.; Huber, D.; Plavchan, P.; Wittenmyer, RA.; Vanderburg, A.; Chaplin, WJ.; Chontos, A.; Clark, JT.; Eastman, JD.; Ziegler, C.; Brahm, R.; Carter, BD.; Clerte, M.; Espinoza, N.; Horner, J.; Bentley, J.; Jordan, A.; Kane, SR.; Kielkopf, JF.; Laychock, E.; Mengel, MW.; Okumura, J.; Stassun, KG.; Bedding, TR.; Bowler, BP.; Burnelis, A.; Blanco-Cuaresma, S.; Collins, M.; Crossfield, I.; Davis, AB.; Evensberget, D.; Heitzmann, A.; Howell, SB.; Law, N.; Mann, AW.; Marsden, SC.; Matson, RA.; O'Connor, JH.; Shporer, A.; Stevens, C.; Tinney, CG.; Tylor, C.; Wang, SH.; Zhang, H.; Henning, T.; Kossakowski, D.; Ricker, G.; Sarkis, P.; Schlecker, M.; Torres, P.; Vanderspek, R.; Latham, DW.; Seager, S.; Winn, JN.; Jenkins, JM.; Mireles, I.; Rowden, P.; Pepper, J.; Daylan, T.; Schlieder, JE.; Collins, KA.; Collins, KI.; Tan, TG.; Ball, WH.; Basu, S.; Buzasi, DL.; Campante, TL.; Corsaro, E.; Gonzalez-Cuesta, L.; Davies, GR.; de Almeida, L.; do Nascimento, JD.; Garcia, RA.; Guo, Z.; Handberg, R.; Hekker, S.; Hey, DR.; Kallinger, T.; Kawaler, SD.; Kayhan, C.; Kuszlewicz, JS.; Lund, MN.; Lyttle, A.; Mathur, S.; Miglio, A.; Mosser, B.; Nielsen, MB.; Serenelli, AM.; Aguirre, VS.; Themessl, N.
Title TOI-257b (HD 19916b): a warm sub-saturn orbiting an evolved F-type star Type
Year 2021 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 502 Issue 3 Pages 3704-3722
Keywords asteroseismology; techniques: photometric; techniques: radial velocities; techniques: spectroscopic; planetary systems; stars: individual (TIC 200723869/TOI-257)
Abstract We report the discovery of a warm sub-Saturn, TOI-257b (HD 19916b), based on data from NASA's Transiting Exoplanet Survey Satellite (TESS). The transit signal was detected by TESS and confirmed to be of planetary origin based on radial velocity observations. An analysis of the TESS photometry, the MINERVA-Australis, FEROS, and HARPS radial velocities, and the asteroseismic data of the stellar oscillations reveals that TOI-257b has a mass of M-P = 0.138 +/- 0.023M(J) (43.9 +/- 7.3 M-circle plus), a radius of R-P = 0.639 +/- 0.013 R-J (7.16 +/- 0.15 R-circle plus), bulk density of 0.65(-0.11)(+0.12) (cgs), and period 18.38818(-0.00084)(+0.00085) days. TOI-257b orbits a bright (V = 7.612 mag) somewhat evolved late F-type star with M-* = 1.390 +/- 0.046(Msun), R-* = 1.888 +/- 0.033 R-sun, T-eff = 6075 +/- 90 K, and vsin i = 11.3 +/- 0.5 kms(-1). Additionally, we find hints for a second non-transiting sub-Saturn mass planet on a similar to 71 day orbit using the radial velocity data. This system joins the ranks of a small number of exoplanet host stars (similar to 100) that have been characterized with asteroseismology. Warm sub-Saturns are rare in the known sample of exoplanets, and thus the discovery of TOI-257b is important in the context of future work studying the formation and migration history of similar planetary systems.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000648998800038 Approved
Call Number UAI @ alexi.delcanto @ Serial 1397
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Author Casassus, S.; Carcamo, M.
Title Variable structure in the PDS 70 disc and uncertainties in radio-interferometric image restoration Type
Year 2022 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 513 Issue 4 Pages 5790-5798
Keywords techniques: interferometric; planets and satellites: formation; protoplanetary discs; stars: individual: PDS 70
Abstract The compact mm-wavelength signal in the central cavity of the PDS 70 disc, revealed by deep ALMA observations, is aligned with unresolved H alpha emission, and is thought to stem from a circumplanetary disc (CPD) around PDS 70c. We revisit the available ALMA data on PDS 70c with alternative imaging strategies, and with special attention to uncertainties and to the impact of the so-called 'JvM correction', which is thought to improve the dynamic range of restored images. We also propose a procedure for the alignment and joint imaging of multi-epoch visibility data. We find that the JvM correction exaggerates the peak signal-to-noise of the data, by up to a factor of 10. In the case of PDS 70, we recover the detection of PDS 70c from the 2019 July data, but only at 8 sigma. However, its non-detection in 2017 Dec. suggests that PDS 70c is variable by at least 42 per cent +/- 13 per cent over a 1.75 yr time-span, so similar to models of the H alpha variability. We also pick up fine structure in the inner disc, such that its peak is offset by similar to 0 ''.04 from the disc centre. The inner disc is variable too, which we tentatively ascribe to Keplerian rotation as well as intrinsic morphological changes.
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Language Summary Language Original Title
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ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000804922200007 Approved
Call Number UAI @ alexi.delcanto @ Serial 1585
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Author Casassus, S.; Christiaens, V.; Carcamo, M.; Perez, S.; Weber, P.; Ercolano, B.; van der Marel, N.; Pinte, C.; Dong, R.B.; Baruteau, C.; Cieza, L.; van Dishoeck, E.F.; Jordan, A.; Price, D.J.; Absil, O.; Arce-Tord, C.; Faramaz, V.; Flores, C.; Reggiani, M.
Title A dusty filament and turbulent CO spirals in HD 135344B-SAO 206462 Type
Year 2021 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 507 Issue 3 Pages 3789-3809
Keywords protoplanetary discs; accretion, accretion discs; planet-disc interactions
Abstract Planet-disc interactions build up local pressure maxima that may halt the radial drift of protoplanetary dust, and pile it up in rings and crescents. ALMA observations of the HD 135344B disc revealed two rings in the thermal continuum stemming from similar to mm-sized dust. At higher frequencies the inner ring is brighter relative to the outer ring, which is also shaped as a crescent rather than a full ring. In near-IR scattered light images, the disc is modulated by a two-armed grand-design spiral originating inside the ALMA inner ring. Such structures may be induced by a massive companion evacuating the central cavity, and by a giant planet in the gap separating both rings, that channels the accretion of small dust and gas through its filamentary wakes while stopping the larger dust from crossing the gap. Here we present ALMA observations in the J = (2 – 1) CO isotopologue lines and in the adjacent continuum, with up to 12 km baselines. Angular resolutions of similar to 0 ''.03 reveal the tentative detection of a filament connecting both rings, and which coincides with a local discontinuity in the pitch angle of the IR spiral, proposed previously as the location of the protoplanet driving this spiral. Line diagnostics suggests that turbulence, or superposed velocity components, is particularly strong in the spirals. The (CO)-C-12(2-1) 3D rotation curve points at stellocentric accretion at radii within the inner dust ring, with a radial velocity of up to similar to 5 per cent +/- 0.5 per cent Keplerian, which corresponds to an excessively large accretion rate of similar to 2 x 10(-6) M circle dot yr(-1) if all of the CO layer follows the (CO)-C-12(2-1) kinematics. This suggests that only the surface layers of the disc are undergoing accretion, and that the line broadening is due to superposed laminar flows.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000708848000046 Approved
Call Number UAI @ alexi.delcanto @ Serial 1484
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Author Elorrieta, F.; Eyheramendy, S.; Palma, W.; Ojeda, C.
Title A novel bivariate autoregressive model for predicting and forecasting irregularly observed time series Type
Year 2021 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 505 Issue 1 Pages 1105-1116
Keywords methods: data analysis; methods: statistical; stars: variables: general; galaxies: general
Abstract In several disciplines, it is common to find time series measured at irregular observational times. In particular, in astronomy there are a large number of surveys that gather information over irregular time gaps and in more than one passband. Some examples are Pan-STARRS, ZTF, and also the LSST. However, current commonly used time series models that estimate the time dependence in astronomical light curves consider the information of each band separately (e.g, CIAR, IAR, and CARMA models) disregarding the dependence that might exist between different passbands. In this paper, we propose a novel bivariate model for irregularly sampled time series, called the Bivariate Irregular Autoregressive (BIAR) model. The BIAR model assumes an autoregressive structure on each time series; it is stationary, and it allows to estimate the autocorrelation, the cross-correlation and the contemporary correlation between two unequally spaced time series. We implemented the BIAR model on light curves, in the g and r bands, obtained from the ZTF alerts processed by the ALeRCE broker. We show that if the light curves of the two bands are highly correlated, the model has more accurate forecast and prediction using the bivariate model than a similar method that uses only univariate information. Further, the estimated parameters of the BIAR are useful to characterize long-period variable stars and to distinguish between classes of stochastic objects, providing promising features that can be used for classification purposes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000671453100074 Approved
Call Number UAI @ alexi.delcanto @ Serial 1437
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Author Espinoza, N.; Brahm, R.; Henning, T.; Jordan, A.; Dorn, C.; Rojas, F.; Sarkis, P.; Kossakowski, D.; Schlecker, M.; Diaz, M.R.; Jenkins, J.S.; Aguilera-Gomez, C.; Jenkins, J.M.; Twicken, J.D.; Collins, K.A.; Lissauer, J.; Armstrong, D.J.; Adibekyan, V.; Barrado, D.; Barros, S.C.C.; Battley, M.; Bayliss, D.; Bouchy, F.; Bryant, E.M.; Cooke, B.F.; Demangeon, O.D.S.; Dumusque, X.; Figueira, P.; Giles, H.; Lillo-Box, J.; Lovis, C.; Nielsen, L.D.; Pepe, F.; Pollaco, D.; Santos, N.C.; Sousa, S.G.; Udry, S.; Wheatley, P.J.; Turner, O.; Marmier, M.; Segransan, D.; Ricker, G.; Latham, D.; Seager, S.; Winn, J.N.; Kielkopf, J.F.; Hart, R.; Wingham, G.; Jensen, E.L.N.; Helminiak, K.G.; Tokovinin, A.; Briceno, C.; Ziegler, C.; Law, N.M.; Mann, A.W.; Daylan, T.; Doty, J.P.; Guerrero, N.; Boyd, P.; Crossfield, I.; Morris, R.L.; Henze, C.E.; Chacon, A.D.
Title HD 213885b: a transiting 1-d-period super-Earth with an Earth-like composition around a bright (V=7.9) star unveiled by TESS Type
Year 2020 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 491 Issue 2 Pages 2982-2999
Keywords techniques: photometric; techniques: radial velocities; planets and satellites: detection; planets and satellites: fundamental parameters; planets and satellites: individual: TOI-141, TIC 403224672, HD213885
Abstract We report the discovery of the 1.008-d, ultrashort period (USP) super-EarthHD213885b (TOI141b) orbiting the bright (V= 7.9) star HD 213885 (TOI-141, TIC 403224672), detected using photometry from the recently launched TESS mission. Using FEROS, HARPS, and CORALIE radial velocities, we measure a precise mass of 8.8 +/- 0.6M. for this 1.74 +/- 0.05 R. exoplanet, which provides enough information to constrain its bulk composition – similar to Earth's but enriched in iron. The radius, mass, and stellar irradiation of HD 213885b are, given our data, very similar to 55 Cancri e, making this exoplanet a good target to perform comparative exoplanetology of short period, highly irradiated super-Earths. Our precise radial velocities reveal an additional 4.78-d signal which we interpret as arising from a second, non-transiting planet in the system, HD 213885c, whoseminimum mass of 19.9 +/- 1.4M. makes it consistent with being a Neptune-mass exoplanet. The HD 213885 system is very interesting from the perspective of future atmospheric characterization, being the second brightest star to host an USP transiting super-Earth (with the brightest star being, in fact, 55 Cancri). Prospects for characterization with present and future observatories are discussed.
Address [Espinoza, Nestor] Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA, Email: nespinoza@stsci.edu
Corporate Author Thesis
Publisher Oxford Univ Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000512302100105 Approved
Call Number UAI @ eduardo.moreno @ Serial 1106
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Author Helminiak, K.G.; Moharana, A.; Pawar, T.; Ukita, N.; Sybilski, P.; Espinoza, N.; Kambe, E.; Ratajczak, M.; Jordan, A.; Maehara, H.; Brahm, R.; Kozlowski, S.K.; Konacki, M.
Title Orbital and physical parameters of eclipsing binaries from the ASAS catalogue – XII. A sample of systems with K2 photometry Type
Year 2021 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 508 Issue 4 Pages 5687-5708
Keywords binaries: eclipsing; binaries: spectroscopic; stars: fundamental parameters; stars: individual: HD 284753; EPIC 202073040, RU Cnc, BD+18 2050, FM Leo, HD 149946, BD-19 4582, HD 219869; stars: late-type
Abstract We present results of the analysis of light and radial velocity (RV) curves of eight detached eclipsing binaries observed by the All-Sky Automated Survey, which we have followed up with high-resolution spectroscopy, and were later observed by the Keplersatellite as part of the K2 mission. The RV measurements came from spectra obtained with OAO-188/HIDES, MPG-2.2m/FEROS, SMARTS 1.5m/CHIRON, Euler/CORALIE, ESO-3.6m/HARPS, and OHP-1.93/ELODIE instruments. The K2 time-series photometry was analysed with the JKTEBOP code, with out-of-eclipse modulations of different origin taken into account. Individual component spectra were retrieved with the fd3 code, and analysed with the code ISPEC in order to determine effective temperatures and metallicities. Absolute values of masses, radii, and other stellar parameters are calculated, as well as ages, found through isochrone fitting. For five systems, such analysis has been done for the first time. The presented sample consists of a variety of stars, from low-mass dwarfs, through G- and F-type main sequence objects, to evolved active sub-giants, one of which is found to be crossing the Hertzsprung gap. One target may contain a gamma Dor-type pulsator, two more are parts of higher-order multiples, and spectra of their tertiaries were also retrieved and used to constrain the properties of these systems.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000715897400062 Approved
Call Number UAI @ alexi.delcanto @ Serial 1498
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Author Kaye, L.; Vissapragada, S.; Gunther, M.N.; Aigrain, S.; Mikal-Evans, T.; Jensen, E.L.N.; Parviainen, H.; Pozuelos, F.J.; Abe, L.; Acton, J.S.; Agabi, A.; Alves, D.R.; Anderson, D.R.; Armstrong, D.J.; Barkaoui, K.; Barragan, O.; Benneke, B.; Boyd, P.T.; Brahm, R.; Bruni, I.; Bryant, E.M.; Burleigh, M.R.; Casewell, S.L.; Ciardi, D.; Cloutier, R.; Collins, K.A.; Collins, K.I.; Conti, D.M.; Crossfield, I.J.M.; Crouzet, N.; Daylan, T.; Dragomir, D.; Dransfield, G.; Fabrycky, D.; Fausnaugh, M.; Gan, T.J.; Gill, S.; Gillon, M.; Goad, M.R.; Gorjian, V.; Greklek-McKeon, M.; Guerrero, N.; Guillot, T.; Jehin, E.; Jenkins, J.S.; Lendl, M.; Kamler, J.; Kane, S.R.; Kielkopf, J.F.; Kunimoto, M.; Marie-Sainte, W.; McCormac, J.; Mekarnia, D.; Morales, F.Y.; Moyano, M.; Palle, E.; Parmentier, V; Relles, H.M.; Schmider, F.X.; Schwarz, R.P.; Seager, S.; Smith, A.M.S.; Tan, T.G.; Taylor, J.; Triaud, A.H.M.J.; Twicken, J.D.; Udry, S.; Vines, J.I.; Wang, G.; Wheatley, P.J.; Winn, J.N.
Title Transit timings variations in the three-planet system: TOI-270 Type
Year 2022 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 510 Issue 4 Pages 5464-5485
Keywords planets and satellites: composition; planets and satellites: formation; planets and satellites: fundamental parameters
Abstract We present ground- and space-based photometric observations of TOI-270 (L231-32), a system of three transiting planets consisting of one super-Earth and two sub-Neptunes discovered by TESS around a bright (K-mag = 8.25) M3V dwarf. The planets orbit near low-order mean-motion resonances (5:3 and 2:1) and are thus expected to exhibit large transit timing variations (TTVs). Following an extensive observing campaign using eight different observatories between 2018 and 2020, we now report a clear detection of TTVs for planets c and d, with amplitudes of similar to 10 min and a super-period of similar to 3 yr, as well as significantly refined estimates of the radii and mean orbital periods of all three planets. Dynamical modelling of the TTVs alone puts strong constraints on the mass ratio of planets c and d and on their eccentricities. When incorporating recently published constraints from radial velocity observations, we obtain masses of M-b = 1.48 +/- 0.18 M-circle plus, M-c = 6.20 +/- 0.31 M-circle plus, and M-d = 4.20 +/- 0.16 M-circle plus for planets b, c, and d, respectively. We also detect small but significant eccentricities for all three planets : e(b) = 0.0167 +/- 0.0084, e(c) = 0.0044 +/- 0.0006, and e(d) = 0.0066 +/- 0.0020. Our findings imply an Earth-like rocky composition for the inner planet, and Earth-like cores with an additional He/H2O atmosphere for the outer two. TOI-270 is now one of the best constrained systems of small transiting planets, and it remains an excellent target for atmospheric characterization.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000764893900001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1552
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Author Kossakowski, D.; Espinoza, N.; Brahm, R.; Jordan, A.; Henning, T.; Rojas, F.; Kurster, M.; Sarkis, P.; Schlecker, M.; Pozuelos, F.J.; Barkaoui, K.; Jehin, E.; Gillon, M.; Matthews, E.; Horch, E.P.; Ciardi, D.R.; Crossfield, I.J.M.; Gonzales, E.; Howell, S.B.; Matson, R.; Schlieder, J.; Jenkins, J.; Ricker, G.; Seager, S.; Winn, J.N.; Li, J.; Rose, M.E.; Smith, J.C.; Dynes, S.; Morgan, E.; Villasenor, J.N.; Charbonneau, D.; Jaffe, T.; Yu, L.; Bakos, G.; Bhatti, W.; Bouchy, F.; Collins, K.A.; Collins, K.I.; Csubry, Z.; Evans, P.; Jensen, E.L.N.; Lovis, C.; Marmier, M.; Nielsen, L.D.; Osip, D.; Pepe, F.; Relles, H.M.; Segransan, D.; Shporer, A.; Stockdale, C.; Suc, V.; Turner, O.; Udry, S.
Title TOI-150b and TOI-163b: two transiting hot Jupiters, one eccentric and one inflated, revealed by TESS near and at the edge of the JWST CVZ Type
Year 2019 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 490 Issue 1 Pages 1094-1110
Keywords techniques: photometric; planets and satellites: detection; stars: individual: HD271181; stars: individual: TIC 179317684; stars: individual: TIC 271893367; stars: individual: TYC9191-519-1
Abstract We present the discovery of TYC9191-519-1b (TOI-150b, TIC 271893367) and HD271181b (TOI-163b, TIC 179317684), two hot Jupiters initially detected using 30-min cadence Transiting Exoplanet Survey Satellite (TESS) photometry from Sector 1 and thoroughly characterized through follow-up photometry (CHAT, Hazelwood, LCO/CTIO, El Sauce, TRAPPIST-S), high-resolution spectroscopy (FEROS, CORALIE), and speckle imaging (Gemini/DSSI), confirming the planetary nature of the two signals. A simultaneous joint fit of photometry and radial velocity using a new fitting package JULIET reveals that TOI-150b is a 1.254 +/- 0.016 R-J, massive (2.61(-0.12)(+0.19) M-J) hot Jupiter in a 5.857-d orbit, while TOI-163b is an inflated (R-P = 1.478(-0.029)(+0.022) R-J, M-P = 1.219 +/- 0.11 M-J) hot Jupiter on a P = 4.231-d orbit; both planets orbit F-type stars. A particularly interesting result is that TOI-150b shows an eccentric orbit (e = 0.262(-0.037)(+0.045)), which is quite uncommon among hot Jupiters. We estimate that this is consistent, however, with the circularization time-scale, which is slightly larger than the age of the system. These two hot Jupiters are both prime candidates for further characterization – in particular, both are excellent candidates for determining spin-orbit alignments via the Rossiter-McLaughlin (RM) effect and for characterizing atmospheric thermal structures using secondary eclipse observations considering they are both located closely to the James Webb Space Telescope (JWST) Continuous Viewing Zone (CVZ).
Address [Kossakowski, Diana; Espinoza, Nestor; Henning, Thomas; Kuerster, Martin; Sarkis, Paula; Schlecker, Martin] Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany, Email: kossakowski@mpia.dc
Corporate Author Thesis
Publisher Oxford Univ Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000496922300078 Approved
Call Number UAI @ eduardo.moreno @ Serial 1076
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Author Lagos, F.; Schreiber, M.R.; Parsons, S.G.; Zurlo, A.; Mesa, D.; Gansicke, B.T.; Brahm, R.; Caceres, C.; Canovas, H.; Hernandez, M.S.; Jordan, A.; Koester, D.; Schmidtobreick, L.; Tappert, C.; Zorotovic, M.
Title The White Dwarf Binary Pathways Survey -III. Contamination from hierarchical triples containing a white dwarf Type
Year 2020 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 494 Issue 1 Pages 915-922
Keywords methods: numerical; methods: statistical; binaries: close; stars: kinematics and dynamics
Abstract The White Dwarf Binary Pathways Survey aims at increasing the number of known detached A, F, G, and K main-sequence stars in close orbits with white dwarf companions (WD+AFGK binaries) to refine our understanding about compact binary evolution and the nature of Supernova Ia progenitors. These close WD+AFGK binary stars are expected to form through common envelope evolution, in which tidal forces tend to circularize the orbit. However, some of the identified WD+AFGK binary candidates show eccentric orbits, indicating that these systems are either formed through a different mechanism or perhaps they are not close WD+AFGK binaries. We observed one of these eccentric WD+AFGK binaries with SPHERE and find that the system TYC 7218-934-1 is in fact a triple system where the WD is a distant companion. The inner binary likely consists of the G-type star plus an unseen low-mass companion in an eccentric orbit. Based on this finding, we estimate the fraction of triple systems that could contaminate the WD+AFGK sample. We find that less than 15 per cent of our targets with orbital periods shorter than 100 d might be hierarchical triples.
Address [Lagos, F.; Schreiber, M. R.; Hernandez, M-S; Tappert, C.; Zorotovic, M.] Univ Valparaiso, Inst Fis & Astron, Valparaiso, Chile, Email: felipe.lagos@pmigrado.uv.cl;
Corporate Author Thesis
Publisher Oxford Univ Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000535885900070 Approved
Call Number UAI @ eduardo.moreno @ Serial 1197
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Author Lendl, M.; Bouchy, F.; Gill, S.; Nielsen, L.D.; Turner, O.; Stassun, K.; Acton, J.S.; Anderson, D.R.; Armstrong, D.J.; Bayliss, D.; Belardi, C.; Bryant, E.M.; Burleigh, M.R.; Chaushev, A.; Casewell, S.L.; Cooke, B.F.; Eigmuller, P.; Gillen, E.; Goad, M.R.; Gunther, M.N.; Hagelberg, J.; Jenkins, J.S.; Louden, T.; Marmier, M.; McCormac, J.; Moyano, M.; Pollacco, D.; Raynard, L.; Tilbrook, R.H.; Udry, S.; Vines, J.I.; West, R.G.; Wheatley, P.J.; Ricker, G.; Vanderspek, R.; Latham, D.W.; Seager, S.; Winn, J.; Jenkins, J.M.; Addison, B.; Briceno, C.; Brahm, R.; Caldwell, D.A.; Doty, J.; Espinoza, N.; Goeke, B.; Henning, T.; Jordan, A.; Krishnamurthy, A.; Law, N.; Morris, R.; Okumura, J.; Mann, A.W.; Rodriguez, J.E.; Sarkis, P.; Schlieder, J.; Twicken, J.D.; Villanueva, S.; Wittenmyer, R.A.; Wright, D.J.; Ziegler, C.
Title TOI-222: a single-transit TESS candidate revealed to be a 34-d eclipsing binary with CORALIE, EulerCam, and NGTS Type
Year 2020 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 492 Issue 2 Pages 1761-1769
Keywords techniques: photometric; stars: individual: TOI-222; planetary systems
Abstract We report the period, eccentricity, and mass determination for the Transiting Exoplanet Survey Satellite (TESS) single-transit event candidate TOI-222, which displayed a single 3000 ppm transit in the TESS 2-min cadence data from Sector 2. We determine the orbital period via radial velocity measurements (P = 33.9 d), which allowed for ground-based photometric detection of two subsequent transits. Our data show that the companion to TOI-222 is a low-mass star, with a radius of 0.18(-0.10)(+0.39) R-circle dot and a mass of 0.23 +/- 0.01 M-circle dot. This discovery showcases the ability to efficiently discover long-period systems from TESS single-transit events using a combination of radial velocity monitoring coupled with high-precision ground-based photometry.
Address [Lendl, Monika; Bouchy, Francois; Nielsen, Louise D.; Turner, Oliver; Hagelberg, Janis; Marmier, Maxime; Udry, Stephane] Univ Geneva, Observ Geneve, 51 Ch Maillettes, CH-1290 Sauverny, Switzerland, Email: monika.lendl@unige.ch
Corporate Author Thesis
Publisher Oxford Univ Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000512297600016 Approved
Call Number UAI @ eduardo.moreno @ Serial 1107
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Author Mahajan, S.M.; Asenjo, F.A.; Hazeltine, R.D.
Title Comparison of the electron-spin force and radiation reaction force Type
Year 2015 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 446 Issue 4 Pages 4112-4115
Keywords magnetic fields; plasmas; radiation mechanisms: general
Abstract It is shown that the forces that originate from the electron-spin interacting with the electromagnetic field can play, along with the Lorentz force, a fundamentally important role in determining the electron motion in a high energy density plasma embedded in strong high-frequency radiation, a situation that pertains to both laser-produced and astrophysical systems. These forces, for instance, dominate the standard radiation reaction force as long as there is a 'sufficiently' strong ambient magnetic field for affecting spin alignment. The inclusion of spin forces in any advanced modelling of electron dynamics pertaining to high energy density systems (for instance in particle-in-cell codes), therefore, is a must.
Address [Mahajan, Swadesh M.; Hazeltine, Richard D.] Univ Texas Austin, Inst Fus Studies, Austin, TX 78712 USA, Email: felipe.asenjo@uai.cl
Corporate Author Thesis
Publisher Oxford Univ Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000350272400066 Approved
Call Number UAI @ eduardo.moreno @ Serial 462
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Author Nowak, G.; Palle, E.; Gandolfi, D.; Deeg, HJ.; Hirano, T.; Barragan, O.; Kuzuhara, M.; Dai, F.; Luque, R.; Persson, CM.; Fridlund, M.; Johnson, MC.; Korth, J.; Livingston, JH.; Grziwa, S.; Mathur, S.; Hatzes, AP.; Prieto-Arranz, J.; Nespral, D.; Hidalgo, D.; Hjorth, M.; Albrecht, S.; Van Eylen, V.; Lam, KWF.; Cochran, WD.; Esposito, M.; Csizmadia, S.; Guenther, EW.; Kabath, P.; Blay, P.; Brahm, R.; Jordan, A.; Espinoza, N.; Rojas, F.; Barris, NC.; Rodler, F.; Sobrino, RA.; Cabrera, J.; Carleo, I.; Chaushev, A.; de Leon, J.; Eigmuller, P.; Endl, M.; Erikson, A.; Fukui, A.; Georgieva, I.; Gonzalez-Cuesta, L.; Knudstrup, E.; Lund, MN.; Rodriguez, PM.; Murgas, F.; Narita, N.; Niraula, P.; Patzold, M.; Rauer, H.; Redfield, S.; Ribas, I.; Skarka, M.; Smith, AMS.; Subjak, J.
Title K2-280 b – a low density warm sub-Saturn around a mildly evolved star Type
Year 2020 Publication MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 497 Issue 4 Pages 4423-4435
Keywords techniques: photometric; techniques: radial velocities; techniques: spectroscopic; planets and satellites: detection; stars: individual: (EPIC 216494238, K2-280)
Abstract We present an independent discovery and detailed characterization of K2-280 b, a transiting low density warm sub-Saturn in a 19.9-d moderately eccentric orbit (e = 0.35(-0.04)(+0.05)) from K2 campaign 7. A joint analysis of high precision HARPS, HARPS-N, and FIES radial velocity measurements and K2 photometric data indicates that K2-280 b has a radius of R-b = 7.50 +/- 0.44 R-circle plus and a mass of M-b = 37.1 +/- 5.6 M-circle plus, yielding a mean density of rho(b) = 0.48(-0.10)(+0.13) g cm(-3). The host star is a mildly evolved G7 star with an effective temperature of T-eff = 5500 +/- 100 K, a surface gravity of log g(star) = 4.21 +/- 0.05 (cgs), and an iron abundance of [Fe/H] = 0.33 +/- 0.08 dex, and with an inferred mass of M-star = 1.03 +/- 0.03 M-circle dot and a radius of R-star = 1.28 +/- 0.07 R-circle dot. We discuss the importance of K2-280 b for testing formation scenarios of sub-Saturn planets and the current sample of this intriguing group of planets that are absent in the Solar system.
Address
Corporate Author Thesis
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Language Summary Language Original Title
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Area Expedition Conference
Notes Approved
Call Number UAI @ alexi.delcanto @ Serial 1276
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Author Osborn, A.; Armstrong, D.J.; Cale, B.; Brahm, R.; Wittenmyer, R.A.; Dai, F.; Crossfield, I.J.M.; Bryant, E.M.; Adibekyan, V.; Cloutier, R.; Collins, K.A.; Mena, E.D.; Fridlund, M.; Hellier, C.; Howell, S.B.; King, G.W.; Lillo-Box, J.; Otegi, J.; Sousa, S.; Stassun, K.G.; Matthews, E.C.; Ziegler, C.; Ricker, G.; Vanderspek, R.; Latham, D.W.; Seager, S.; Winn, J.N.; Jenkins, J.M.; Acton, J.S.; Addison, B.C.; Anderson, D.R.; Ballard, S.; Barrado, D.; Barros, S.C.C.; Batalha, N.; Bayliss, D.; Barclay, T.; Benneke, B.; Berberian, J.; Bouchy, F.; Bowler, B.P.; Briceno, C.; Burke, C.J.; Burleigh, M.R.; Casewell, S.L.; Ciardi, D.; Collins, K.I.; Cooke, B.F.; Demangeon, O.D.S.; Diaz, R.F.; Dorn, C.; Dragomir, D.; Dressing, C.; Dumusque, X.; Espinoza, N.; Figueira, P.; Fulton, B.; Furlan, E.; Gaidos, E.; Geneser, C.; Gill, S.; Goad, M.R.; Gonzales, E.J.; Gorjian, V.; Gunther, M.N.; Helled, R.; Henderson, B.A.; Henning, T.; Hogan, A.; Hojjatpanah, S.; Horner, J.; Howard, A.W.; Hoyer, S.; Huber, D.; Isaacson, H.; Jenkins, J.S.; Jensen, E.L.N.; Jordan, A.; Kane, S.R.; Kidwell, R.C.; Kielkopf, J.; Law, N.; Lendl, M.; Lund, M.; Matson, R.A.; Mann, A.W.; McCormac, J.; Mengel, M.W.; Morales, F.Y.; Nielsen, L.D.; Okumura, J.; Osborn, H.P.; Petigura, E.A.; Plavchan, P.; Pollacco, D.; Quintana, E.V.; Raynard, L.; Robertson, P.; Rose, M.E.; Roy, A.; Reefe, M.; Santerne, A.; Santos, N.C.; Sarkis, P.; Schlieder, J.; Schwarz, R.P.; Scott, N.J.; Shporer, A.; Smith, A.M.S.; Stibbard, C.; Stockdale, C.; Strom, P.A.; Twicken, J.D.; Tan, T.G.; Tanner, A.; Teske, J.; Tilbrook, R.H.; Tinney, C.G.; Udry, S.; Villasenor, J.N.; Vines, J.I.; Wang, S.X.; Weiss, L.M.; West, R.G.; Wheatley, P.J.; Wright, D.J.; Zhang, H.; Zohrabi, F.
Title TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet Type
Year 2021 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 507 Issue 2 Pages 2782-2803
Keywords planets and satellites: detection; planets and satellites: fundamental parameters; planets and satellites: individual: (TOI-431, TIC 31374837)
Abstract We present the bright (V-mag = 9.12), multiplanet system TOI-431, characterized with photometry and radial velocities (RVs). We estimate the stellar rotation period to be 30.5 +/- 0.7 d using archival photometry and RVs. Transiting Exoplanet Survey Satellite (TESS) objects of Interest (TOI)-431b is a super-Earth with a period of 0.49 d, a radius of 1.28 +/- 0.04 R-circle plus, a mass of 3.07 +/- 0.35 M-circle plus, and a density of 8.0 +/- 1.0 g cm(-3); TOI-431 d is a sub-Neptune with a period of 12.46 d, a radius of 3.29 +/- 0.09 R-circle plus, a mass of M-circle plus, and a density of 1.36 +/- 0.25 g cm(-3). We find a third planet, TOI-431c, in the High Accuracy Radial velocity Planet Searcher RV data, but it is not seen to transit in the TESS light curves. It has an Msin i of M-circle plus, and a period of 4.85 d. TOI-431d likely has an extended atmosphere and is one of the most well-suited TESS discoveries for atmospheric characterization, while the super-Earth TOI-431b may be a stripped core. These planets straddle the radius gap, presenting an interesting case-study for atmospheric evolution, and TOI-431b is a prime TESS discovery for the study of rocky planet phase curves.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000697380800082 Approved
Call Number UAI @ alexi.delcanto @ Serial 1485
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Author Sandford, E.; Espinoza, N.; Brahm, R.; Jordan, A.
Title Estimation of singly transiting K2 planet periods with Gaia parallaxes Type
Year 2019 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 489 Issue 3 Pages 3149-3161
Keywords methods: data analysis; methods: statistical; planets and satellites: fundamental parameters; stars: planetary systems
Abstract When a planet is only observed to transit once, direct measurement of its period is impossible. It is possible, however, to constrain the periods of single transiters, and this is desirable as they are likely to represent the cold and far extremes of the planet population observed by any particular survey. Improving the accuracy with which the period of single transiters can be constrained is therefore critical to enhance the long-period planet yield of surveys. Here, we combine Gaia parallaxes with stellar models and broad-band photometry to estimate the stellar densities of K2 planet host stars, then use that stellar density information to model individual planet transits and infer the posterior period distribution. We show that the densities we infer are reliable by comparing with densities derived through asteroseismology, and apply our method to 27 validation planets of known (directly measured) period, treating each transit as if it were the only one, as well as to 12 true single transiters. When we treat eccentricity as a free parameter, we achieve a fractional period uncertainty over the true single transits of 94(-58)(+87) per cent, and when we fix e = 0, we achieve fractional period uncertainty 15(-6)(+30) per cent, a roughly threefold improvement over typical period uncertainties of previous studies.
Address [Sandford, Emily] Columbia Univ, Dept Astron, 550 W 120th St, New York, NY 10027 USA, Email: esandford@astro.columbia.edu
Corporate Author Thesis
Publisher Oxford Univ Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000489288600015 Approved
Call Number UAI @ eduardo.moreno @ Serial 1088
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Author Sedaghati, E.; MacDonald, R.J.; Casasayas-Barris, N.; Hoeijmakers, H.J.; Boffin, H.M.J.; Rodler, F.; Brahm, R.; Jones, M.; Sanchez-Lopez, A.; Carleo, I.; Figueira, P.; Mehner, A.; Lopez-Puertas, M.
Title A spectral survey of WASP-19b with ESPRESSO Type
Year 2021 Publication Monthly Notices Of The Royal Astronomical Society Abbreviated Journal Mon. Not. Roy. Astron. Soc.
Volume 505 Issue 1 Pages 435-458
Keywords methods: data analysis; techniques: spectroscopic; planets and satellites: atmospheres; planets and satellites: individual: WASP-19b; stars: activity; stars: individual: WASP-19
Abstract High-resolution precision spectroscopy provides a multitude of robust techniques for probing exoplanetary atmospheres. We present multiple VLT/ESPRESSO transit observations of the hot-Jupiter exoplanet WASP-19b with previously published but disputed atmospheric features from low resolution studies. Through spectral synthesis and modelling of the Rossiter-McLaughlin (RM) effect we calculate stellar, orbital and physical parameters for the system. From narrow-band spectroscopy we do not detect any of Hi, Fei, Mgi, Cai, Nai, and Ki neutral species, placing upper limits on their line contrasts. Through cross-correlation analyses with atmospheric models, we do not detect Fei and place a 3 sigma upper limit of on its mass fraction, from injection and retrieval. We show the inability to detect the presence of H2O for known abundances, owing to lack of strong absorption bands, as well as relatively low S/N ratio. We detect a barely significant peak (3.02 +/- 0.15 sigma) in the cross-correlation map for TiO, consistent with the sub-solar abundance previously reported. This is merely a hint for the presence of TiO and does not constitute a confirmation. However, we do confirm the presence of previously observed enhanced scattering towards blue wavelengths, through chromatic RM measurements, pointing to a hazy atmosphere. We finally present a reanalysis of low-resolution transmission spectra of this exoplanet, concluding that unocculted starspots alone cannot explain previously detected features. Our reanalysis of the FORS2 spectra of WASP-19b finds a similar to 100x sub-solar TiO abundance, precisely constrained to , consistent with the TiO hint from ESPRESSO. We present plausible paths to reconciliation with other seemingly contradicting results.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
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ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes WOS:000671453100031 Approved
Call Number UAI @ alexi.delcanto @ Serial 1438
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