DOCSLIB.ORG

Activity Induced Variation in Spin-Orbit Angles As Derived from Rossiter–Mclaughlin Measurements M

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Activity Induced Variation in Spin-Orbit Angles As Derived from Rossiter–Mclaughlin Measurements M A&A 619, A150 (2018) https://doi.org/10.1051/0004-6361/201833709 Astronomy & © ESO 2018 Astrophysics Activity induced variation in spin-orbit angles as derived from Rossiter–McLaughlin measurements M. Oshagh1,2, A. H. M. J. Triaud3, A. Burdanov4, P. Figueira2,5, A. Reiners1, N. C. Santos2,6, J. Faria2, G. Boue7, R. F. Díaz8,9, S. Dreizler1, S. Boldt1, L. Delrez10, E. Ducrot4, M. Gillon4, A. Guzman Mesa1, E. Jehin4, S. Khalafinejad11,12, S. Kohl11, L. Serrano2, and S. Udry13 1 Institut für Astrophysik, Georg-August Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany e-mail: [email protected] 2 Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal 3 University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK 4 Space Sciences, Technologies and Astrophysics Research (STAR) Institute, Université de Liège, Allée du 6 Août 17, Bat. B5C, 4000 Liège, Belgium 5 European Southern Observatory, Alonso de Cordova 3107, Vitacura Casilla 19001, Santiago 19, Chile 6 Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal 7 IMCCE, Observatoire de Paris, UPMC University Paris 6, PSL Research University, Paris, France 8 Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Buenos Aires 1428, Argentina 9 CONICET – Universidad de Buenos Aires, Instituto de Astronomía y Física del Espacio (IAFE), Buenos Aires 1428, Argentina 10 Astrophysics Group, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK 11 Hamburg Observatory, Hamburg University, Gojenbergsweg 112, 21029 Hamburg, Germany 12 Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany 13 Observatoire de Genève, Université de Genève, 51 chemin des Maillettes, 1290 Versoix, Switzerland Received 25 June 2018 / Accepted 17 August 2018 ABSTRACT One of the most powerful methods used to estimate sky-projected spin-orbit angles of exoplanetary systems is through a spectroscopic transit observation known as the Rossiter–McLaughlin (RM) effect. So far mostly single RM observations have been used to estimate the spin-orbit angle, and thus there have been no studies regarding the variation of estimated spin-orbit angle from transit to transit. Stellar activity can alter the shape of photometric transit light curves and in a similar way they can deform the RM signal. In this paper we present several RM observations, obtained using the HARPS spectrograph, of known transiting planets that all transit extremely active stars, and by analyzing them individually we assess the variation in the estimated spin-orbit angle. Our results reveal that the estimated spin-orbit angle can vary significantly (up to ∼42◦) from transit to transit, due to variation in the configuration of stellar active regions over different nights. This finding is almost two times larger than the expected variation predicted from simulations. We could not identify any meaningful correlation between the variation of estimated spin-orbit angles and the stellar magnetic activity indicators. We also investigated two possible approaches to mitigate the stellar activity influence on RM observations. The first strategy was based on obtaining several RM observations and folding them to reduce the stellar activity noise. Our results demonstrated that this is a feasible and robust way to overcome this issue. The second approach is based on acquiring simultaneous high-precision short-cadence photometric transit light curves using TRAPPIST/SPECULOOS telescopes, which provide more information about the stellar active region’s properties and allow a better RM modeling. Key words. planets and satellites: fundamental parameters – planets and satellites: detection – stars: activity – starspots – techniques: radial velocities – techniques: photometric 1. Introduction formation, planets should form on aligned orbits λ ∼ 0 (Pollack et al. 1996; and see a comprehensive review in Dawson & Understanding the orbital architecture of exoplanetary systems Johnson 2018, and references therein), as observed in the case is one of the main objectives of exoplanetary surveys, in order of the solar system. Planetary evolution mechanisms such as to provide new strong constraints on the physical mechanisms disk migration predict that planets should maintain their pri- behind planetary formation and evolution. The sky-projected 1 mordial spin-orbit angle, but the dynamical interactions with a spin-orbit angle (hereafter spin-orbit angle λ) is one of the third body and tidal migration could alter the spin-orbit angle most important parameters of the orbital architecture of plane- (see a comprehensive review in Baruteau et al. 2014, and ref- tary systems. According to the core-accretion paradigm of planet erences therein). Moreover, several studies have shown that the misalignment of a planet could be primordial considering the 1 The angle between the stellar spin axis and normal to the planetary disks being naturally and initially misaligned (e.g., Batygin 2012; orbital plane. Crida & Batygin 2014). In this context, the measurement of Article published by EDP Sciences A150, page 1 of 17 A&A 619, A150 (2018) spin-orbit angles under a wide range of host and planet condi- In this paper we assess the impact of stellar activity on the tions (including multiple transiting planets) is extremely impor- spin-orbit angle estimation by observing several RM observa- tant in order to obtain feedback on modeling. tions of known transiting planets which all transit extremely As a star rotates, the part of its surface that rotates toward active stars. We organize our paper as follows. We describe our the observer is blueshifted and the part that rotates away is targets’ selection and their observations in Sect.2. In Sect.3 we redshifted. During the transit of a planet, the corresponding rota- define our fitting procedure to estimate the spin-orbit angles, and tional velocity of the portion of the stellar disk that is blocked also present its result. We investigate the possibility of mitigating by the planet is removed from the integration of the velocity the influence of stellar activity on RM observations by combin- over the entire star, creating a radial velocity (RV) signal known ing several RM observations in Sect.4. In Sect.5 we present as the Rossiter–McLaughlin (RM) effect (Holt 1893; Rossiter the simultaneous photometric transit observation with our RM 1924; McLaughlin 1924). The RM observation is the most pow- observation and we discuss the advantages of having simultane- erful and efficient technique for estimating the spin-orbit angle λ ous photometric transit observation in eliminating stellar activity of exoplanetary systems or eclipsing binary systems (e.g., Winn noise in RM observations. In Sect.6, we discuss possible con- et al. 2005; Hébrard et al. 2008; Triaud et al. 2010; Albrecht tamination from other sources of stellar noise that affect our et al. 2012, and a comprehensive review in Triaud 2017, and refer- observations, and conclude in Sect7. ences therein). The number of spin-orbit angle λ measurements has dramatically increased over the past decade (200 systems to date)2, and have revealed a large number of unexpected systems, 2. Observations and data reduction which include planets on highly misaligned (e.g., Triaud et al. 2.1. Target selection 2010; Albrecht et al. 2012; Santerne et al. 2014), polar (e.g., Our stars were selected following four main criteria: Addison et al. 2013), and even retrograde orbits (e.g., Bayliss – the star should have a known transiting planet; et al. 2010; Hébrard et al. 2011). – the planet host star should be very active (e.g., the published The contrast of active regions (i.e., stellar spots, plages, photometric transit light curves clearly show large stellar and faculae) present on the stellar surface during the transit of spots’ occultation anomalies); an exoplanet alter the high-precision photometric transit light – at least one RM measurement of the planet has been curve (both outside and inside transit) and lead to an inaccurate observed (preferably with the HARPS spectrograph as we estimate of the planetary parameters (e.g., Czesla et al. 2009; use HARPS observations in our study) to ensure the feasi- Sanchis-Ojeda & Winn 2011; Sanchis-Ojeda et al. 2013; Oshagh bility of detecting the RM signal; et al. 2013b, 2015a,b; Barros et al. 2013; Ioannidis et al. 2016). – the transiting planet should have several observable tran- Since the physics and geometry behind the transit light curve sits from the southern hemisphere during the period from and the RM measurement are the same, the RM observations are March 2017 to October 2017 (this criterion is to ensure expected to be affected by the presence of stellar active regions observability). in a similar way. Furthermore, the inhibition of the convective Our criteria resulted in the selection of six transiting exo- blueshift inside the active regions can induce extra RV noise on planets, namely, WASP-6b, WASP-19b, WASP-41b, WASP-52b, the RM observations, which is absent in the photometric transit CoRoT-2b, and Qatar-2b. Their published transit light curves observation. have indicated the presence of stellar spots on their surfaces Boldt et al. (in prep.) demonstrate, using simulations, that with a filling factor of 6, 8, 3, 15, 16, and 4%, respectively unocculted stellar active regions during the planetary transit (Nutzman et al. 2011; Tregloan-Reed et al. 2015; Sedaghati et al. influence the RV slope of out-of-transit in RM observations (due 2015; Southworth et al. 2016; Mancini et al. 2017; Dai et al. to a combination of contrast and stellar rotation) and leads to 2017). Most of them also have at least one observed RM with an inaccurate estimate of the planetary radius; however, their HARPS (Bouchy et al. 2008; Gillon et al. 2009; Hellier et al. influence on the estimated λ was negligible. On the other hand, 2011; Neveu-VanMalle et al. 2016), except for Qatar-2, which has Oshagh et al.(2016) demonstrated that the occulted stellar active one observed RM with the HARPS-N spectrograph (Esposito regions can lead to quite significant inaccuracies in the estima- et al.
Load more

Recommended publications
  • Greeting Fellow Naturalists. As of This Writing, We Have Come Back To
    Hawk Watch Team by John Wright Galveston Bay Area Chapter - Texas Master Naturalists June 2018 Table of Contents President’s Corner by George Kyame, President 2018 Wetland Wanderings 2 Prairie Ponderings 2 Greeting Fellow Naturalists. Dire Diseases in 3 As of this writing, we have come back to reality after an interesting spring. The mercury Deer, Part 2 finally hit 90, and won't be changing soon. Of course this means we must properly AT: iNaturalist 4 prepare for all of our outdoor stewardship. Please remember the big three: hydration, AT: Gems of the Gulf 5 sun protective clothing, and SPF 30 and above. A cooler beginning to 2018 was nice, although it was accompanied by a rather rainy season, which brings me to my next Heritage Book Study - 6 point. Review The Big Picture - 6 Ah, Beach and Bay. Last year's record attendance would be hard to beat even without Ocean Worlds and the wind and rain that was visited upon us! Impressive was the number of attendees Our World’s Oceans that did come out, and, with our dedicated volunteers, braved the elements! Alas, we Another Botany 8 shut down a little early, but not before our participants got some extra hands-on Question attention. Thank you all for the hard work. AT: The Big Thicket 8 The City Nature Challenge wrapped up 96 hours of species observation on April 30. So 2018 Class Fun and 10 how did the Houston Metro fare? In the Most Species category (my favorite), Houston Adventures placed 2nd. We were 1st last year.
    [Show full text]
  • SPECULOOS Search for Habitable Planets Eclipsing Ultra-Cool Stars
    SPECULOOS Search for habitable Planets EClipsing ULtra-cOOl Stars M. Gillon ([email protected]), E. Jehin, L. Delrez, P. Magain, C. Opitom, S. Sohy Department of Astrophysics, Geophysics and Oceanography (AGO), University of Liège, Belgium Transiting planets: treasures in the sky TRAPPIST/UCDTS : the prototype Among the hundreds of planets detected outside our solar system, the ones No existing transit survey is optimized for detecting Earth-size planets transiting the that transit their parent star are genuine Rosetta Stones for the study of nearest ultra-cool stars. Extensive simulations show us that robotic 1m-class exoplanets, because they can be studied in greatest detail. Indeed, their orbital telescopes equipped with modern CCD cameras highly sensitive in near-IR, operating parameters, mass and radius can be precisely measured, and their atmosphere from an exquisite astronomical site, and monitoring individually nearby ultra-cool can be probed during and outside eclipses, bringing strong constraints on their stars, should be able to probe eficiently their habitable zone for terrestrial planets. actual nature (Winn 2010). Within the last two decades, more than three hundred transiting exoplanets have been detected. This large harvest includes many gas giants, but also a steeply growing fraction of terrestrial planets. In parallel to this galore of detections, many projects aiming to characterize giant exoplanets have been successful, bringing notably a Eirst glimpse at their atmospheric properties (Seager & Deming 2010). Fig. 3. Actual TRAPPIST/UCDTS light curves for three ultra-cool stars, aer injecBon of a fake transit of an habitable Earth-size planet. The best-fit transit models are overimposed in red.
    [Show full text]
  • Présentation Powerpoint
    Hunting for habitable exoplanets around the nearest very-low-mass stars Michaël Gillon (University of Liège, Belgium) CERN– 17 Jan 2019 Is our blue world unique? Credit: NASA Earth: a rocky planet hosting a complex surface biosphere Credit: NASA Earth: a rocky planet with surface liquid water « Habitable » planet Credits: Howard Perlman, USGS The « habitable zone » of the Sun Credits: NASA No little green men on Mars Credits: NASA We must search beyond our solar system Credits: Ryan Sullivan 1995: beginning of the exoplanet era A giant planet in very short orbit around a Sun-like star Didier Queloz Michel Mayor The exoplanet revolution 51 Peg b 9 Planets everywhere Credits: ESO/M. Kornmesser The diversity of planetary systems Compact Hot Jupiters systems Very eccentric Free-floating orbits planets Credits: NASA/JPL-Caltech; Northwestern University; SETI Institute 11 A few dozen possible biospheres A few dozen BILLIONS in the whole Milky Way! 12 A few exoplanets have been imaged Spectroscopy of terrestrial planets Best spectral range for the detection of molecules is infrared Infrared spectroscopy of potentially habitable exoplanets Spectroscopy of exoplanets Imaging planets around other stars Imaging planets around other stars Planetary transit Transit of exoplanet Credits: Deeg & Garrido Atmospheric study of a transiting exoplanet Credits: C. Daniloff/MIT, J. de Wit 20 Atmospheric study of a transiting exoplanet Credits: E. Sedaghati et al. 2018 21 Atmospheric study of a transiting exoplanet Credits: NASA/JPL 22 Atmospheric study of a transiting exoplanet Credits: Grillmair et al. 2008 23 The smaller the star, the better Low-mass stars are small and cold Credits: ESO The habitable zone of hot and cold stars Credits: NASA 26 Most stars are smaller and colder than the Sun 27 Search for habitable Planets EClipsing ULtra-cOOl Stars Search for habitable Planets EClipsing ULtra-cOOl Stars What are « ultra-cool stars »? Ultracool dwarfs: Teff < 2700K, (Kirckpatrick erSun al.
    [Show full text]
  • SPECULOOS: Ultracool Dwarf Transit Survey Target List and Strategy?
    A&A 645, A100 (2021) Astronomy https://doi.org/10.1051/0004-6361/202038827 & c ESO 2021 Astrophysics SPECULOOS: Ultracool dwarf transit survey Target list and strategy? D. Sebastian1, M. Gillon1, E. Ducrot1, F. J. Pozuelos1,3, L. J. Garcia1, M. N. Günther4, L. Delrez1,3,5 , D. Queloz2, B. O. Demory6, A. H. M. J. Triaud7, A. Burgasser8, J. de Wit4, A. Burdanov4, G. Dransfield7, E. Jehin3, J. McCormac9, C. A. Murray2, P. Niraula4, P. P. Pedersen2, B. V. Rackham4, S. Sohy3, S. Thompson2, and V. Van Grootel3 1 Astrobiology Research Unit, University of Liège, Allée du 6 Août, 19, 4000 Liège, Sart-Tilman, Belgium e-mail: [email protected] 2 Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE, UK 3 Space Sciences, Technologies and Astrophysics Research (STAR) Institute, Université de Liège, Allée du 6 Août 19C, 4000 Liège, Belgium 4 Department of Earth, Atmospheric and Planetary Sciences, MIT, 77 Massachusetts Avenue, Cambridge, MA 02139, USA 5 Observatoire de l’Université de Genéve, Chemin des Maillettes 51, Versoix 1290, Switzerland 6 University of Bern, Center for Space and Habitability, Gesellschaftsstrasse 6, 3012 Bern, Switzerland 7 School of Physics & Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK 8 University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA 9 Department of Physics, University of Warwick, Coventry CV4 7AL, UK Received 2 July 2020 / Accepted 27 October 2020 ABSTRACT Context. One of the most promising avenues for the detailed study of temperate Earth-sized exoplanets is the detection of such planets in transit in front of stars that are small and near enough to make it possible to carry out a thorough atmospheric characterisation with next-generation telescopes, such as the James Webb Space telescope (JWST) or Extremely Large Telescope (ELT).
    [Show full text]
  • Activity Induced Variation in Spin-Orbit Angles As Derived from Rossiter-Mclaughlin Measurements? M
    Astronomy & Astrophysics manuscript no. RM-VARIATION-ARXIV c ESO 2018 September 5, 2018 Activity induced variation in spin-orbit angles as derived from Rossiter-McLaughlin measurements? M. Oshagh1;2, A. H. M. J. Triaud3, A. Burdanov4, P. Figueira2;5, A. Reiners1, N. C. Santos2;6, J. Faria2, G. Boue7, R. F. D´ıaz8;9, S. Dreizler1, S. Boldt1, L. Delrez10, E. Ducrot4, M. Gillon4, A. Guzman Mesa1, E. Jehin4, S. Khalafinejad11;12, S. Kohl11, L. Serrano2, S. Udry13 1 Institut f¨urAstrophysik, Georg-August Universit¨atG¨ottingen,Friedrich-Hund-Platz 1, 37077 G¨ottingen,Germany 2 Instituto de Astrof´ısicae Ci^enciasdo Espa¸co,Universidade do Porto, CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal 3 University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK 4 Space sciences, Technologies and Astrophysics Research (STAR) Institute, Universit´ede Li`ege, All´eedu 6 Ao^ut17, Bat. B5C, 4000 Li`ege,Belgium 5 European Southern Observatory, Alonso de Cordova 3107, Vitacura Casilla 19001, Santiago 19, Chile 6 Departamento de F´ısicae Astronomia, Faculdade de Ci^encias,Universidade do Porto,Rua do Campo Alegre, 4169- 007 Porto, Portugal 7 IMCCE, Observatoire de Paris, UPMC Univ. Paris 6, PSL Research University, Paris, France 8 Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Buenos Aires, 1428, Argentina 9 CONICET - Universidad de Buenos Aires, Instituto de Astronoma y F´ısicadel Espacio (IAFE), Buenos Aires, 1428, Argentina 10 Astrophysics Group, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge, CB3 0HE, UK 11 Hamburg Observatory, Hamburg University, Gojenbergsweg 112, 21029, Hamburg, Germany 12 Max Planck Institute for Astronomy, K¨onigstuhl17, 69117 Heidelberg, Germany 13 Observatoire de Gen`eve, Universit´ede Gen`eve, 51 chemin des Maillettes, 1290 Versoix, Switzerland Received XXX; accepted XXX ABSTRACT One of the most powerful methods used to estimate sky-projected spin-orbit angles of exoplanetary systems is through a spectroscopic transit observation known as the RossiterMcLaughlin (RM) effect.
    [Show full text]
  • Shadows of Other Worlds Two Telescopes Due to Launch This Year Should Reveal a Host of New Exoplanets by Joshua N
    ORBITING A RED DWARF, this imagined planet has its own moon. Both are bathed in a warm glow from the star and its flares. PLANETARY SCIENCE SHADOWS OF OTHER WORLDS Two telescopes due to launch this year should reveal a host of new exoplanets By Joshua N. Winn Illustrations by Ron Miller sad0318Winn4p.indd 32 1/23/18 4:54 PM IN BRIEF The world’s most prolific planet-hunting satellite, NASA’s Kepler spacecraft, is preparing to shut down, but several new missions target- ing exoplanets are due to launch this year. The Transiting Exoplanet Survey Satellite (TESS) and the Characterising Exoplanet Satellite ( CHEOPS) will both search for signs of other worlds crossing in front of their parent stars. Scientists stand to add many SHADOWS OF OTHER WORLDS more exoplanets to the grow- ing tally, which should help them get closer to answering two questions: Are there oth- er habitable worlds out there, and is there life beyond Earth in the universe? March 2018, ScientificAmerican.com 33 sad0318Winn4p.indd 33 1/23/18 4:54 PM Joshua N. Winn is an astrophysicist at Princeton University, who studies how planets form and evolve around other stars. He was a participating scientist in the NASA Kepler team and is a co-investigator for the upcoming Transiting Exoplanet Survey Satellite (TESS). 21, 2017, , , great anticipation. In a few minutes we would be enveloped by the moon’s shadow. Along with millions of other people who had made their way to a narrow strip of land extending from Ore- gon to South Carolina, we were about to see a total eclipse of the sun.
    [Show full text]
  • Billy Edwards, Lorenzo Mugnai, Giovanna Tinetti
    @EXOLEMONS POTENTIAL TARGETS FOR ARIEL BILLY EDWARDS, LORENZO MUGNAI, GIOVANNA TINETTI, ENZO PASCALE AND SUBHAJIT SARKAR Does Ariel’s current design allow us to achieve our science goals? Ariel Exoplanet Catalogue Master Catalogue NASA Exoplanet Catalogue Supplementary Catalogues Exoplanet.eu Open Exoplanet Catalogue TEPCat Ariel Exoplanet Catalogue Master Catalogue TESS Exoplanet Yield NASA Exoplanet Catalogue Barclay, Pepper & Quintana, 2018 Supplementary Catalogues Methodology Exoplanet.eu Catalogue of target stars Open Exoplanet Catalogue Planetary Occurrence Statistics TEPCat Likelihood of detection with TESS Ariel Exoplanet Catalogue • Many more surveys will provide planets for Ariel to characterise Kepler/K2 KELT HAT-Net CARMENES PLATO KPS SPIRO ESPRESSO WASP CHEOPS NGTS HARPS MEarth HAT-South SPECULOOS ArielRad Mugnai, Pascale, Edwards et al., in prep Edwards et al. 2019 Mission Candiate Sample • Tier 1: • ∼2000 planets in ≤ 5 observations • Tier 2: • ∼1000 planets in ≤ 20 observations • Tier 3: • ∼150 planets in ≤ 2 observations Example Mission Reference Sample Edwards et al. 2019 Edwards et al. 2019 Example Mission Reference Sample Edwards et al. 2019 + 10% mission time for other science (e.g. phase-curves, targets of opportunity) Does Ariel’s current design allow us to achieve our science goals? How do we maximise the scientific yield of Ariel? Exploring Different Samples Edwards et al. 2019 Fulton et al. 2018 Discuss MRS with Community Discuss MRS with Community Before After Thanks to Laura Mayorga and Vivien Parmentier! Continue
    [Show full text]
  • The SPECULOOS Southern Observatory Begins Its Hunt for Rocky Planets
    Telescopes and Instrumentation DOI: 10.18727/0722-6691/5105 The SPECULOOS Southern Observatory Begins its Hunt for Rocky Planets Emmanuël Jehin1 The SPECULOOS Southern Observa- Jupiter, effective temperatures lower than Michaël Gillon 2,1 tory (SSO), a new facility of four 1- 2700 K, and luminosities less than one Didier Queloz3, 4 metre robotic telescopes, began scien- thousandth that of the Sun. Laetitia Delrez 3 tific operations at Cerro Paranal on Artem Burdanov1 1 January 2019. The main goal of the The habitable zones in these systems Catriona Murray 3 SPECULOOS project is to explore are very close to the host stars, corre- Sandrine Sohy1 approximately 1000 of the smallest sponding to orbital periods of only a few 1 Elsa Ducrot (≤ 0.15 R⊙), brightest (Kmag ≤ 12.5), and days. This proximity to the host star Daniel Sebastian1 nearest (d ≤ 40 pc) very low mass stars maximises the transit probability and the Samantha Thompson 3 and brown dwarfs. It aims to discover likelihood of detecting habitable planets. James McCormac 5 transiting temperate terrestrial planets In addition, an Earth-sized planet transit- Yaseen Almleaky 6 well-suited for detailed atmospheric ing a small UCD star produces a 1% Adam J. Burgasser 7 characterisation with future giant tele- transit signal, 100 times deeper than that Brice-Olivier Demory 8 scopes like ESO’s Extremely Large of an equivalent transit around a Sun-like Julien de Wit 9 Telescope (ELT) and the NASA James star, and well within the reach of ground- Khalid Barkaoui 2,1 Webb Telescope (JWST). The SSO is based telescopes.
    [Show full text]
  • Exoplanetary Atmospheres: Key Insights, Challenges and Prospects
    Exoplanetary Atmospheres: Key Insights, Challenges and Prospects Nikku Madhusudhan1 1Institute of Astronomy, University of Cambridge, Cambridge, UK, CB3 0HA; email: [email protected] xxxxxx 0000. 00:1{59 Keywords Copyright c 0000 by Annual Reviews. Extrasolar planets, exoplanetary atmospheres, planet formation, All rights reserved habitability, atmospheric composition Abstract Exoplanetary science is on the verge of an unprecedented revolution. The thousands of exoplanets discovered over the past decade have most recently been supplemented by discoveries of potentially habitable planets around nearby low-mass stars. Currently, the field is rapidly progressing towards detailed spectroscopic observations to characterise the atmospheres of these planets. While various surveys from space and ground are expected to detect numerous more exoplanets orbiting nearby stars, the imminent launch of JWST along with large ground- based facilities are expected to revolutionise exoplanetary spectroscopy. Such observations, combined with detailed theoretical models and in- verse methods, provide valuable insights into a wide range of physi- cal processes and chemical compositions in exoplanetary atmospheres. Depending on the planetary properties, the knowledge of atmospheric compositions can also place important constraints on planetary forma- tion and migration mechanisms, geophysical processes and, ultimately, arXiv:1904.03190v1 [astro-ph.EP] 5 Apr 2019 biosignatures. In the present review, we will discuss the modern and future landscape of this frontier area of exoplanetary atmospheres. We will start with a brief review of the area, emphasising the key insights gained from different observational methods and theoretical studies. This is followed by an in-depth discussion of the state-of-the-art, chal- lenges, and future prospects in three forefront branches of the area.
    [Show full text]
  • Instrumentation for the Detection and Characterization of Exoplanets
    Instrumentation for the detection and characterization of exoplanets Francesco Pepe1, David Ehrenreich1, Michael R. Meyer2 1Observatoire Astronomique de l'Université de Genève, 51 ch. des Maillettes, 1290 Versoix, Switzerland 2Swiss Federal Institute of Technology, Institute for Astronomy, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland In no other field of astrophysics has the impact of new instrumentation been as substantial as in the domain of exoplanets. Before 1995 our knowledge about exoplanets was mainly based on philosophical and theoretical considerations. The following years have been marked, instead, by surprising discoveries made possible by high-precision instruments. More recently the availability of new techniques moved the focus from detection to the characterization of exoplanets. Next- generation facilities will produce even more complementary data that will lead to a comprehensive view of exoplanet characteristics and, by comparison with theoretical models, to a better understanding of planet formation. Astrometry is the most ancient technique of astronomy. It is therefore not surprising that the first (unconfirmed) detection of an extra-solar planet arose through this technique1. In 1984, another detection of a planetary-mass object around the nearby star VB 8 was claimed, this time using speckle interferometry2, but subsequent attempts to locate it were unsuccessful. It was finally Doppler velocimetry that delivered the first unambiguous detection of a probable brown dwarf around HD 1147623. In 1992, a handful of bodies of terrestrial mass were found4 and confirmed, by the measurement of timing variation, to orbit the pulsar PSR1257+12. Although very powerful, this technique was restricted to a small number of very particular hosts.
    [Show full text]
  • Exoplanet Science Review 2015
    Exoplanets science review panel: Prof Paul O’Brien (Chair, Leicester) Dr Chris Arridge (Lancaster) Dr Stephen Lowry (Kent) Prof Richard Nelson (QMUL) Prof Don Pollacco (Warwick) Dr David Sing (Exeter) Prof Giovanna Tinetti (UCL) Dr Chris Watson (QUB) ESO/L Calcada Support from STFC provided by: Michelle Cooper and Sharon Bonfield SCIENCE AND TECHNOLOGY FACILITIES COUNCIL EXOPLANET SCIENCE REVIEW PANEL REPORT 2015 Science and Technology Facilities Council Exoplanet Science Review Panel Report 2015 Executive summary There are few questions more scientifically- and sociologically-fundamental than whether or not the Earth is a unique environment in the Universe. For most of human history attempts to answer this question have been lim- ited to studies of environments within our own Solar System. Today we are on the brink of being able to answer the question directly by determining the detailed properties of exoplanets – planets orbiting stars other than the Sun. Following the discovery of the first exoplanets, found just twenty years ago, there are now more than one thousand confirmed planets, and thousands of candidates, exoplanets ranging from giant planets larger than Jupi- ter to smaller Earth-sized objects. We now know that the Solar System is far from being the archetype for all plan- etary systems; indeed the complexity and diversity of exoplanetary systems and how they change over time has been a revelation. The UK has been strongly involved in exoplanet research since the early days, leveraging its expertise in astronomy and solar system science, contributing to studies ranging from the discovery of planets and determination of their sizes and masses, to detection of molecules in exoplanetary atmospheres, through to the development of theoretical models of planetary atmospheres/interiors and the formation and evolution of plane- tary systems.
    [Show full text]
  • The Transiting Exoplanet Survey Satellite Promises to Discover Small Planets Around the Nearest and Brightest Stars
    A Quick Look into the first year of discoveries from TESS Full Frame Images: Chelsea Huang (MIT) The Transiting Exoplanet Survey Satellite promises to discover small planets around the nearest and brightest stars. After the first year of observations, the TESS mission has recovered more than a thousand planetary candidates in the Full Frame Images around bright stars. In this talk, we present a quick look into the TESS Full Frame Image data and some of its exciting discoveries from it. Using these discoveries as examples, I will review the process of planetary candidate identification in TESS Full Frame Images using the MIT Quick Look Pipeline and discuss the potential of space-based wide-field transit survey. Wide-field high-precision photometry with NGTS: Peter Wheatley (University of Warwick) Ultra-High Precision Photometry with NGTS Multi-Telescopes :Ed Bryant (University of Warwick) The Next Generation Transit Survey (NGTS) is an exoplanet hunting facility consisting of 12x20cm aperture robotic telescopes, situated at ESO's Paranal Observatory. I will present a new mode of observing in which we observe bright stars simultaneously with multiple NGTS telescopes/cameras. Using this observing method, we can obtain ultra-high precision light curves with precisions comparable to TESS. NGTS is able to monitor very bright stars (V < 9.5 mag), because the very wide field-of-view (8deg2) of NGTS provides us with the necessary number of comparison stars. Obtaining these bright star light curves is crucial for refining transit ephemerides and planetary radii for future atmospheric characterisation studies. With these ultra-high precision light curves, we can also achieve transit timing precisions on the order of 10s.
    [Show full text]