image: This spectacular image from the SPHERE instrument on ESO's Very Large Telescope is the first clear image of a planet caught in the very act of formation around the dwarf star PDS 70. The planet stands clearly out, visible as a bright point to the right of the center of the image, which is blacked out by the coronagraph mask used to block the blinding light of the central star. view more
Credit: ESO/A. Müller et al.
Astronomers led by a group at the Max Planck Institute for Astronomy in Heidelberg, Germany have captured a spectacular snapshot of planetary formation around the young dwarf star PDS 70. By using the SPHERE instrument on ESO's (https://www.eso.org/public/ ) Very Large Telescope (VLT) -- one of the most powerful planet-hunting instruments in existence -- the international team has made the first robust detection of a young planet, named PDS 70b, cleaving a path through the planet-forming material surrounding the young star [1].
The SPHERE instrument also enabled the team to measure the brightness of the planet at different wavelengths, which allowed properties of its atmosphere to be deduced.
The planet stands out very clearly in the new observations, visible as a bright point to the right of the blackened centre of the image. It is located roughly three billion kilometres from the central star, roughly equivalent to the distance between Uranus and the Sun. The analysis shows that PDS 70b is a giant gas planet with a mass a few times that of Jupiter. The planet's surface has a temperature of around 1000°C, making it much hotter than any planet in our own Solar System.
The dark region at the centre of the image is due to a coronagraph, a mask which blocks the blinding light of the central star and allows astronomers to detect its much fainter disc and planetary companion. Without this mask, the faint light from the planet would be utterly overwhelmed by the intense brightness of PDS 70.
"These discs around young stars are the birthplaces of planets, but so far only a handful of observations have detected hints of baby planets in them," explains Miriam Keppler, who lead the team behind the discovery of PDS 70's still-forming planet. "The problem is that until now, most of these planet candidates could just have been features in the disc."
The discovery of PDS 70's young companion is an exciting scientific result that has already merited further investigation. A second team, involving many of the same astronomers as the discovery team, including Keppler, has in the past months followed up the initial observations to investigate PDS 70's fledgling planetary companion in more detail. They not only made the spectacularly clear image of the planet shown here, but were even able to obtain a spectrum of the planet. Analysis of this spectrum indicated that its atmosphere is cloudy.
PDS 70's planetary companion has sculpted a transition disc -- a protoplanetary disc with a giant "hole" in the centre. These inner gaps have been known about for decades and it has been speculated that they were produced by disc-planet interaction. Now we can see the planet for the first time.
"Keppler's results give us a new window onto the complex and poorly-understood early stages of planetary evolution," comments André Müller, leader of the second team to investigate the young planet. "We needed to observe a planet in a young star's disc to really understand the processes behind planet formation." By determining the planet's atmospheric and physical properties, the astronomers are able to test theoretical models of planet formation.
This glimpse of the dust-shrouded birth of a planet was only possible thanks to the impressive technological capabilities of ESO's SPHERE instrument, which studies exoplanets and discs around nearby stars using a technique known as high-contrast imaging -- a challenging feat. Even when blocking the light from a star with a coronagraph, SPHERE still has to use cleverly devised observing strategies and data processing techniques to filter out the signal of the faint planetary companions around bright young stars [2] at multiple wavelengths and epochs.
Thomas Henning, director at the Max Planck Institute for Astronomy and leader of the teams, summarises the scientific adventure: "After more than a decade of enormous efforts to build this high-tech machine, now SPHERE enables us to reap the harvest with the discovery of baby planets!"
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Notes
[1] The disc and planet images and the planet's spectrum have been captured in the course of the two survey programmes called SHINE (SpHere INfrared survey for Exoplanets) and DISK (sphere survey for circumstellar DISK). SHINE aims to image 600 young nearby stars in the near-infrared using SPHERE's high contrast and high angular resolution to discover and characterise new exoplanets and planetary systems. DISK explores known, young planetary systems and their circumstellar discs to study the initial conditions of planetary formation and the evolution of planetary architectures.
[2] In order to tease out the weak signal of the planet next to the bright star, astronomers use a sophisticated method that benefits from the Earth's rotation. In this observing mode, SPHERE continuously takes images of the star over a period of several hours, while keeping the instrument as stable as possible. As a consequence, the planet appears to slowly rotate, changing its location on the image with respect to the stellar halo. Using elaborate numerical algorithms, the individual images are then combined in such a way that all parts of the image that appear not to move during the observation, such as the signal from the star itself, are filtered. This leaves only those that do apparently move -- making the planet visible.
More information
This research was presented in two papers, entitled "Discovery of a planetary-mass companion within the gap of the transition disk around PDS 70" and "Orbital and atmospheric characterization of the planet within the gap of the PDS 70 transition disk", both to be published in Astronomy & Astrophysics.
The team behind the discovery paper is composed of M. Keppler (Max Planck Institute for Astronomy, Heidelberg, Germany), M. Benisty (Univ. Grenoble, France and Unidad Mixta Internacional Franco-Chilena de Astronomía, Chile), A. Müller (Max Planck Institute for Astronomy, Heidelberg, Germany), Th. Henning (Max Planck Institute for Astronomy, Heidelberg, Germany), R. van Boekel (Max Planck Institute for Astronomy, Heidelberg, Germany), F. Cantalloube (Max Planck Institute for Astronomy, Heidelberg, Germany), C. Ginski (Leiden Observatory, The Netherlands), R.G. van Holstein (Leiden Observatory, The Netherlands), A.-L. Maire (Max Planck Institute for Astronomy, Heidelberg, Germany), A. Pohl (Max Planck Institute for Astronomy, Heidelberg, Germany), M. Samland (Max Planck Institute for Astronomy, Heidelberg, Germany), H. Avenhaus (Max Planck Institute for Astronomy, Heidelberg, Germany), J.-L. Baudino (Department of Physics, University of Oxford, Oxford, UK), A. Boccaletti (LESIA, Observatoire de Paris, France), J. de Boer (Leiden Observatory, The Netherlands), M. Bonnefoy (Univ. Grenoble, France), S. Desidera (INAF - Osservatorio Astronomico di Padova, Italy), M. Langlois (Aix Marseille Univ, CNRS, LAM, Marseille, France and CRAL, UMR 5574, CNRS, Université de Lyon, Ecole Normale Supérieure de Lyon, France), C. Lazzoni (INAF - Osservatorio Astronomico di Padova, Italy), N. Pawellek (Max Planck Institute for Astronomy, Heidelberg, Germany), T. Stolker (Institute for Particle Physics and Astrophysics, ETH Zurich, Switzerland), A. Vigan (Aix Marseille Univ, CNRS, LAM, Marseille, France), T. Birnstiel (University Observatory, Faculty of Physics, Ludwig-Maximilians- Universität München, Germany), W. Brandner(Max Planck Institute for Astronomy, Heidelberg, Germany), G. Chauvin (Univ. Grenoble, France and Unidad Mixta Internacional Franco-Chilena de Astronomía, Chile), M. Feldt (Max Planck Institute for Astronomy, Heidelberg, Germany), M. Flock (Jet Propulsion Laboratory, California Institute of Technology, USA and Kavli Institute For Theoretical Physics, University of California, USA), J. Girard(Univ. Grenoble, France and ESO, Chile), R. Gratton (INAF - Osservatorio Astronomico di Padova, Italy), J. Hagelberg (Univ. Grenoble, France), A. Isella (Rice University, Department of Physics and Astronomy, USA), M. Janson (Max Planck Institute for Astronomy, Heidelberg, Germany and Department of Astronomy, Stockholm University, Sweden), A. Juhasz (Institute of Astronomy, Cambridge, UK), J. Kemmer (Max Planck Institute for Astronomy, Heidelberg, Germany), Q. Kral (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, France and Institute of Astronomy, Cambridge, UK), A.-M. Lagrange (Univ. Grenoble, France), R. Launhardt (Max Planck Institute for Astronomy, Heidelberg, Germany), G. Marleau (Institut für Astronomie und Astrophysik, Eberhard Karls Universität Tübingen, Germany and Max Planck Institute for Astronomy, Heidelberg, Germany) A. Matter (Université Côte d'Azur, OCA, CNRS, France), F. Ménard (Univ. Grenoble, France), J. Milli (ESO, Chile), P. Mollière (Leiden Observatory, The Netherlands), C. Mordasini (Physikalisches Institut, Universität Bern, Switzerland), J. Olofsson (Max Planck Institute for Astronomy, Heidelberg, Germany, Instituto de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso, Chile, and Núcleo Milenio Formación Planetaria - NPF, Universidad de Valparaíso, Chile), L. Pérez (Max-Planck-Institute for Astronomy, Bonn, Germany and Universidad de Chile, Departamento de Astronomia, Chile), P. Pinilla (Department of Astronomy/Steward Observatory, University of Arizona, USA), C. Pinte (Univ. Grenoble, France, UMI-FCA, CNRS/INSU, France (UMI 3386), and Dept. de Astronomía, Universidad de Chile, Chile, and Monash Centre for Astrophysics (MoCA) and School of Physics and Astronomy, Monash University, Australia), S. Quanz (Institute for Particle Physics and Astrophysics, ETH Zurich, Switzerland), T. Schmidt (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, Univ. Paris 06, Univ. Paris Diderot, France), S. Udry (Geneva Observatory, University of Geneva, Switzerland), Z. Wahhaj (ESO, Chile), J. Williams (Institute for Astronomy, University of Hawaii at Manoa, Honolulu, USA), A. Zurlo (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France, Núcleo de Astronomía, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Chile, Escuela de Ingeniería Industrial, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Chile), E. Buenzli (Institute for Particle Physics and Astrophysics, ETH Zurich, Switzerland), M. Cudel (Univ. Grenoble, France), R. Galicher (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, Univ. Paris 06, Univ. Paris Diderot, France), M. Kasper (ESO, Germany), J. Lannier (Univ. Grenoble, France), D. Mesa (INAF - Osservatorio Astronomico di Padova, Italy and INCT, Universidad De Atacama, Copiapó, Chile), D. Mouillet (Univ. Grenoble, France), S. Peretti (Geneva Observatory, University of Geneva, Switzerland), C. Perrot (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, France), G. Salter (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), E. Sissa (INAF - Osservatorio Astronomico di Padova, Italy), F. Wildi (Geneva Observatory, University of Geneva, Switzerland), L. Abe (Université Côte d'Azur, OCA, CNRS, Lagrange, France), J. Antichi (INAF - Osservatorio Astrofisico di Arcetri, Italy), J.-C. Augereau (Univ. Grenoble, France), P. Baudoz (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, France), J.-L. Beuzit (Univ. Grenoble, France), P. Blanchard (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), S. S. Brems (Landessternwarte Königstuhl, Zentrum für Astronomie der Universität Heidelberg, Germany), M. Carle (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), A. Cheetham (Geneva Observatory, University of Geneva, Switzerland), A. Costille (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), A. Delboulbé (Univ. Grenoble, France), C. Dominik (Anton Pannekoek Institute for Astronomy, The Netherlands), P. Feautrier (Univ. Grenoble, France), L. Gluck (Univ. Grenoble, France), D. Gisler (Institute for Particle Physics and Astrophysics, ETH Zurich, Switzerland), Y. Magnard (Univ. Grenoble, France), D. Maurel (Univ. Grenoble, France), M. Meyer (Institute for Particle Physics and Astrophysics, ETH Zurich, Switzerland), T. Moulin (Univ. Grenoble, France), T. Buey (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, Univ. Paris 06, Univ. Paris Diderot, France), A. Baruffolo (INAF - Osservatorio Astronomico di Padova, Italy), A. Bazzon (Institute for Particle Physics and Astrophysics, ETH Zurich, Switzerland), V. De Caprio (INAF - Osservatorio Astronomico di Capodimonte, Italy), M. Carbillet (Université Côte d'Azur, OCA, CNRS, Lagrange, France), E. Cascone (INAF - Osservatorio Astronomico di Capodimonte, Italy), R. Claudi (INAF - Osservatorio Astronomico di Padova, Italy), K. Dohlen (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), D. Fantinel (INAF - Osservatorio Astronomico di Padova, Italy), T. Fusco (ONERA (Office National d'Etudes et de Recherches Aérospatiales), France), E. Giro (INAF - Osservatorio Astronomico di Padova, Italy), C. Gry (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), N. Hubin (ESO, Germany), E. Hugot (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), M. Jaquet (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), D. Le Mignant (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), M. Llored (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), O. Möller-Nilsson (Max Planck Institute for Astronomy, Heidelberg, Germany), F. Madec (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), P. Martinez (Université Côte d'Azur, OCA, CNRS, Lagrange, France), L. Mugnier (ONERA (Office National d'Etudes et de Recherches Aérospatiales), France), A. Origné (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), P. Puget (Univ. Grenoble, France), D. Perret (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, Univ. Paris 06, Univ. Paris Diderot, France), J. Pragt (NOVA Optical Infrared Instrumentation Group, Dwingeloo, The Netherlands), F. Rigal (Anton Pannekoek Institute for Astronomy, The Netherlands), R. Roelfsema (NOVA Optical Infrared Instrumentation Group, Dwingeloo, The Netherlands), A. Pavlov (Max Planck Institute for Astronomy, Heidelberg, Germany), C. Petit (ONERA (Office National d'Etudes et de Recherches Aérospatiales), France), G. Rousset (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, Univ. Paris 06, Univ. Paris Diderot, France), J. Ramos (Max Planck Institute for Astronomy, Heidelberg, Germany), P. Rabou (Univ. Grenoble, France), S. Rochat (Univ. Grenoble, France), A. Roux (Univ. Grenoble, France), B. Salasnich (INAF - Osservatorio Astronomico di Padova, Italy),C. Soenke (ESO, Germany), E. Stadler (Univ. Grenoble, France), J.-F. Sauvage (ONERA (Office National d'Etudes et de Recherches Aérospatiales), France), M. Suarez ( INAF - Osservatorio Astrofisico di Arcetri, Italy), A. Sevin (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, Univ. Paris 06, Univ. Paris Diderot, France), M. Turatto (INAF - Osservatorio Astronomico di Padova, Italy), L. Weber (Geneva Observatory, University of Geneva, Switzerland).
The team behind the characterisation paper consisted of A. Müller (Max Planck Institute for Astronomy, Heidelberg, Germany), M. Keppler (Max Planck Institute for Astronomy, Heidelberg, Germany), Th. Henning (Max Planck Institute for Astronomy, Heidelberg, Germany), M. Samland (Max Planck Institute for Astronomy, Heidelberg, Germany), G. Chauvin (Univ. Grenoble Alpes, France and Unidad Mixta Internacional Franco-Chilena de Astronomía, CNRS/INSU Universidad de Chile, Chile), H. Beust (Univ. Grenoble Alpes, France), A.-L. Maire (Max Planck Institute for Astronomy, Heidelberg, Germany), K. Molaverdikhani (Max Planck Institute for Astronomy, Heidelberg, Germany), R. van Boekel (Max Planck Institute for Astronomy, Heidelberg, Germany), M. Benisty (Univ. Grenoble Alpes, France and Unidad Mixta Internacional Franco-Chilena de Astronomía, CNRS/INSU Universidad de Chile, Chile), A. Boccaletti (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, Univ. Paris 06, Univ. Paris Diderot, France), M. Bonnefoy (Univ. Grenoble Alpes, France), F. Cantalloube (Max Planck Institute for Astronomy, Heidelberg, Germany), B. Charnay (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, Univ. Paris 06, Univ. Paris Diderot, France), J.-L. Baudino (Department of Physics, University of Oxford, UK), M. Gennaro (Space Telescope Science Institute, USA), Z. C. Long (Space Telescope Science Institute, USA), A. Cheetham (Geneva Observatory, University of Geneva, Switzerland), S. Desidera (INAF - Osservatorio Astronomico di Padova, Italy), M. Feldt (Max Planck Institute for Astronomy, Heidelberg, Germany), T. Fusco (DOTA, ONERA, Université Paris Saclay, and Aix Marseille Université, CNRS, LAM Marseille, France), J. Girard (Univ. Grenoble Alpes, France and Space Telescope Science Institute, USA), R. Gratton (INAF - Osservatorio Astronomico di Padova, Italy), J. Hagelberg (Institute for Particle Physics and Astrophysics, ETH Zurich, Switzerland), M. Janson (Max Planck Institute for Astronomy, Heidelberg, Germany and Department of Astronomy, Stockholm University, Sweden), A.-M. Lagrange (Univ. Grenoble Alpes, France), M. Langlois (Aix Marseille Univ, CNRS, LAM, Marseille, France and CRAL, UMR 5574, CNRS, Université de Lyon, Ecole Normale Supérieure de Lyon, France), C. Lazzoni (INAF - Osservatorio Astronomico di Padova, Italy), R. Ligi (INAF-Osservatorio Astronomico di Brera, Italy), F. Ménard (Univ. Grenoble Alpes, France), D. Mesa (INAF - Osservatorio Astronomico di Padova, Italy and INCT, Universidad De Atacama, Copiapó, Atacama, Chile), M. Meyer (Institute for Particle Physics and Astrophysics, ETH Zurich, Switzerland and Department of Astronomy, University of Michigan, USA), P. Mollière (Leiden Observatory, Leiden University, the Netherlands), C. Mordasini (Physikalisches Institut, Universität Bern, Switzerland), T. Moulin (Univ. Grenoble Alpes, France), A. Pavlov (Max Planck Institute for Astronomy, Heidelberg, Germany), N. Pawellek (Max Planck Institute for Astronomy, Heidelberg, Germany and Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Hungary), S. Quanz (Institute for Particle Physics and Astrophysics, ETH Zurich, Switzerland), J. Ramos (Max Planck Institute for Astronomy, Heidelberg, Germany), D. Rouan (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC, Univ. Paris 06, Univ. Paris Diderot, France), E. Sissa (INAF - Osservatorio Astronomico di Padova, Italy), E. Stadler (Univ. Grenoble Alpes, France), A. Vigan (Aix Marseille Univ, CNRS, LAM, Laboratoire d'Astrophysique de Marseille, France), Z. Wahhaj (ESO, Chile), L. Weber (Geneva Observatory, University of Geneva, Switzerland), A. Zurlo (Núcleo de Astronomía, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Chile, Escuela de Ingeniería Industrial, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Chile).
ESO is the foremost intergovernmental astronomy organisation in Europe and the world's most productive ground-based astronomical observatory by far. It has 15 Member States: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and with Australia as a strategic partner. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become "the world's biggest eye on the sky".
Links
* Research papers:
- Keppler et al. - http://www.eso.org/public/archives/releases/sciencepapers/eso1821/eso1821a.pdf
- Müller et al. - http://www.eso.org/public/archives/releases/sciencepapers/eso1821/eso1821b.pdf
* Photos of the VLT - http://www.eso.org/public/images/archive/category/paranal/
Contacts
Miriam Keppler
Max Planck Institute for Astronomy
Heidelberg, Germany
Tel: +49 6221 528 203
Email: keppler@mpia.de
André Müller
Max Planck Institute for Astronomy
Heidelberg, Germany
Tel: +49 6221 528 227
Email: amueller@mpia.de
Thomas Henning
Max Planck Institute for Astronomy
Heidelberg, Germany
Tel: +49 6221 528 200
Email: henning@mpia.de
Mariya Lyubenova
ESO Outreach Astronomer
Garching bei München, Germany
Tel: +49 89 3200 6188
Email: mlyubeno@eso.org