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Institut d'Astrophysique et
de Géophysique (Bât. B5c)

Quartier Agora
Allée du 6 août, 19C
B-4000 Liège 1 (Sart-Tilman)
Belgique

Tel.: 04.366.9774
Fax: 04.366.9729

Séminaires

Des séminaires sont régulièrement organisés pour permettre aux chercheurs du Département ainsi qu'à des scientifiques extérieurs de présenter les dernières découvertes dans leurs domaines.
Vous y êtes cordialement invités :

03/10/2019 :
16h00  
Early-Type Magnetic Stars: The Rotation Challenge
Gautier Mathys
11/10/2019 :
11h00  
Studying Habitable Zones with Precision Infrared Interferometry
Steve Ertel
28/11/2019 :
16h00  
Accessing outer space as a field for scientific exploration and research : the legal aspects
Jean-François Mayence
Archives : 2019 - 2018 - 2017 - 2016 - 2015 - 2014 - 2013 - 2012 - 2011 - 2010
2009 - 2008 - 2007 - 2006 - 2005 - 2004 - 2003 - 2002 - 2001
Recherche avancée
Séminaire suivant Jeudi 03 octobre, 16h00 (17ème séminaire 2019 - affiche)
Early-Type Magnetic Stars: The Rotation Challenge
Gautier Mathys (ESO)

Salle de réunion AGO (local -1/14), Institut d'Astrophysique et de Géophysique
Bâtiment B5c, Quartier Agora, Allée du 6 Août, 19C, B-4000 Liège 1 (Sart-Tilman)


Large-scale organised magnetic fields of kG order are present in 5–10% of the upper main-sequence stars. The rotation periods of these stars span 5 or 6 orders of magnitude, with no evidence for evolution besides conservation of the angular momentum during their main-sequence lifteime. Explaining how period differentiation over such a wide range is achieved in stars that are essentially at the same evolutionary stage represents a major challenge. To address it, improved knowledge of the distribution of the rotation periods is a pre-requisite. Space- and ground-based photometric surveys have already enabled considerable progress to be achieved in the study of the periods of days to months, and they will continue to do so in the coming years. Magnetic field measurements lend themselves better to the monitoring of the longer periods. The most extreme among the latter, which may reach decades to centuries, are of particular interest, but constraining them is also the most challenging endeavour. Recent progress in this area will be reviewed, and future prospects and concerns will be discussed.


Café, thé et biscuits seront servis après le séminaire...
Séminaire précédant Séminaire suivant Vendredi 11 octobre, 11h00 (18ème séminaire 2019 - affiche)
Veuillez noter l'heure inhabituelle !
Studying Habitable Zones with Precision Infrared Interferometry
Steve Ertel (Université d’Arizona.)

Salle de réunion AGO (local -1/14), Institut d'Astrophysique et de Géophysique
Bâtiment B5c, Quartier Agora, Allée du 6 Août, 19C, B-4000 Liège 1 (Sart-Tilman)


Exozodiacal dust is warm and hot dust in the inner regions of planetary systems. In analogy to our Solar system’s zodiacal dust, it is located in and around a star’s habitable zone (HZ), and closer in. Studying the distribution, origin, and evolution this dust provides crucial present-day insight into the architectures of planetary systems, in particular their inner regions including a star’s HZ. On the other hand, the HZ dust levels around the target stars of future exo-Earth imaging missions are critical for the mission design and success as the presence of dust adds noise and confusion to these observations. Detecting the dust requires precision interferometry due to its proximity and high contrast to the host star. Over the last years, we have carried out the NASA funded HOSTS (Hunt for Observable Signatures of Terrestrial planetary Systems) survey. We used nulling interferometry on the Large Binocular Telescope Interferometer (LBTI) to suppress the bright star light and detected the thermal emission of the HZ dust in N band around a quarter of our target stars. We have also used over the past decade optical long baseline interferometry to survey a large sample of stars for hotter dust even closer to the star, providing dozens of detections. I will review the results from these studies with particular focus on the recent HOSTS survey. I will also briefly discuss the LBTI as a high angular resolution, high contrast, low thermal background imager and interferometer for general astronomical observations at mid-infrared wavelengths.
Séminaire précédant Jeudi 28 novembre, 16h00 (19ème séminaire 2019 - affiche) 
Veuillez noter le lieu inhabituel !
Accessing outer space as a field for scientific exploration and research : the legal aspects
Jean-François Mayence (Legal Advisor BELSPO (Belgian Federal Office for Science Policy))

Salle A3, Petits Amphithéâtres - Galerie des Arts
Bâtiment B7b, Quartier Agora, Allée du 6 Août, 15, B-4000 Liège 1 (Sart-Tilman)


Outer space is for everyone. That’s a common saying. But what does it actually mean? What are the principles applicable to space activities, space areas and space resources? Are there any legal limits to human expansion in outer space? What is left from the peaceful cooperation mottoes of the 60’s?

At the very time the global space community is shifting to the so called “New Space”, the realm of Elon Musk, national defense agencies and smart start-ups, what is the part that outer space law can still save for scientists? How can lawyers use this new reality, made of cubesat constellations, asteroid mining and orbital advertising, to protect science and even provide research with new opportunities?

What is space law made of, and does it fit current challenges?
Université de Liège > Faculté des Sciences > Département d'Astrophysique, Géophysique et Océanographie : CoWebAGO, Juin 2009.