Archivi tag: brown dwarfs

From super-Earths to brown dwarfs: Who’s Who?

The year 2015 marks the 20th anniversary of the discovery of 51 Peg b, the first confirmed exoplanet around a Sun-like star. This detection has triggered extraordinary development in exoplanet research all around the world, through various observational techniques such as radial velocity variations, transit, microlensing, direct imaging and astrometry. Continua a leggere From super-Earths to brown dwarfs: Who’s Who?

Astronomy at high angular resolution

Recent years have seen a huge development in high-resolution astronomical techniques, which are critical to progress in many different areas of astronomy. These techniques can be divided in direct methods (Adaptive optics, lucky imaging), interferometry (including speckle imaging and spectro-astrometry), and reconstruction methods (astrotomography). This workshop aims at bringing together the different communities working on these fields and increase the synergies between them. It is indeed often necessary to combine all these techniques together in order to have a coherent and comprehensive idea of all the processes at work in a given astronomical environment. Continua a leggere Astronomy at high angular resolution

The Brown Dwarf to Exoplanet Connection Conference

The Brown Dwarf to Exoplanet Connection Conference (or #BDEXOCON) will be held on the campus of the University of Delaware on October 23rd – 24th, 2014. The goal is to bring together researchers with an expertise in the atmospheres and formation of both both brown dwarfs and exoplanets for a lively discussion of the current, future, and overlap status of the fields.

Cool Stars, Stellar Systems and the Sun

The “Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun” (also known as “Cool Stars”) has been running for 34 years since the first one was held in Cambridge, Massachusetts, in 1980. Previous Cool Stars venues include Santa Fe, NM; Boulder, CO; Seattle, WA; Tucson, AZ; Athens, GA; Florence, Italy; Tenerife, Spain; Hamburg, Germany; Pasadena, CA; St. Andrews, Scotland; and Barcelona, Spain. Lowell Observatory is proud to add Flagstaff, Arizona to this long list of distinguished cities.  Continua a leggere Cool Stars, Stellar Systems and the Sun

Discovered a close neighbor of the Sun

This image is an artist’s conception of the brown dwarf WISE J085510.83-071442.5. The Sun is the bright star directly to the right of the brown dwarf. Credit: Robert Hurt/JPL, Janella Williams/Penn State University.

A “brown dwarf” star that appears to be the coldest of its kind — as frosty as Earth’s North Pole — has been discovered by a Penn State University astronomer using NASA’s Wide-field Infrared Survey Explorer (WISE) and Spitzer Space Telescopes. Images from the space telescopes also pinpointed the object’s distance at 7.2 light-years away, making it the fourth closest system to our Sun.

More at Penn State: Star Is Discovered To Be a Close Neighbor of the Sun and the Coldest of Its Kind

Gaia and the Unseen: The Brown Dwarf Question

We are pleased to announce a workshop to discuss the impact of Gaia on the science of brown dwarfs. Gaia will revolutionise Astronomy and the study of brown dwarfs is no exception. We are organizing this meeting to mix the brown dwarf and Gaia communities at this important time when the mission is working and we can realistically evaluate the possibilities for advances in this field.

Ionising processes in atmospheric environments of planets, Brown Dwarfs, and M-dwarfs

The atmospheres of planets and very low-mass (VLM) stars are cold enough that clouds form and affect the local chemistry and the spectral appearance. Prominent planetary examples are the giant gas planet HD189733b and the super-Earth GJ1214b in which hazes block the view onto the gaseous atmosphere in the optical and mid-IR spectral ranges. Similar effects need to be expected in VLM stars, which in addition, are suggested to have strong magnetic fields. These magnetic fields add to the mystery of VLM stars as their rotational braking is  much less efficient than expected pointing to an inefficient magnetic field coupling.  How do atmospheric ionisation processes and processes causing magnetic field interaction differ in extraterrestrial environments compared to the solar system? Which role do magnetic-field modulated cosmic rays play?

Ionisation processes have been studied in well-defined areas of astro and geophysics. The study of the interaction of the atmospheric environment with the object’s magnetic field can allow for a  mutual benefit between these scientific communities. This meeting therefore invites astrophysics, geologists and meteorologists to exchange and discuss their views on ionisation, charge separation and discharge processes.

Exoplanets and Brown Dwarfs: Mind the Gap!

The University of Hertfordshire is delighted to be hosting Exoplanets and Brown Dwarfs: Mind the Gap. This year represents a milestone of sorts as the 18th anniversary of the first discoveries of both planets around Sun-like stars and brown dwarfs. The last 18 years have seen the study of these fascinating objects flourish into diverse and exciting astronomical fields. However, as these scientific siblings reach adulthood, there is a danger of missed opportunities as they drift apart. The aim of this meeting is to bring the exoplanet and brown dwarf communities together to explore common science questions, share exciting results, and foster collaboration to overcome shared challenges.

Brown Dwarfs come of Age

An international conference on Brown Dwarfs will be held next May in the sunny island of Fuerteventura, exactly 11 years after the first IAU Symposium devoted to these once elusive objects and 18 years after the definitive observational confirmation of their existence. Much work has been done in the last two decades, both from the theoretical and observational point of view. Time is ripe now to have a conference to provide a comprehensive overview of this very active field of research. Some of the most relevant work on Brown Dwarfs has been done in the Canarian Observatories, making Canary Islands an ideal location to host this conference. Fuerteventura is the easternmost island of the Canaries, rich of unique natural spaces and impressive landscapes. It is well connected by direct flights with many European cities and offers many possibilities of affordable and comfortable accommodation. This island is working to preserve its dark night sky and become a Starlight Reserve.

Wide-area surveys such as DENIS, SDSS and 2MASS have played a major role in the discoveries of some of the first brown dwarfs and the definition of the spectral classes L and T. Recently completed and ongoing surveys such as IPHAS, PANSTARS, UKIDSS and WISE are shedding new light on the field. An even cooler spectral class, the Y dwarfs, has been revealed. Detailed studies of brown dwarfs have uncovered surprising behaviours such as ultra-fast rotation rates, the presence of clouds, polarization and strong radio emission. Observations of dust in disks around very low-mass primaries with the Spitzer and Herschel satellites have provided information on the conditions of planet formation. Brown dwarfs have become prime interest targets for searches for habitable planets due to their small masses and radii, and the presence of a habitable regions very close to them for extended periods of time. Brown dwarfs populate the natural bridge between stars and planets. As such, they are connected with both types of objects. One of the main focus of this international conference will be to examine whether the fundamental properties of brown dwarfs represent a smooth continuity from stars to planets or not. Brown dwarfs and their extension into planetary masses represent the low-mass end of the stellar IMF. Deep observations of young open clusters and star-forming regions and microlensing surveys have found a population of very low-mass brown dwarfs or free-floating planets.

Our conference will provide a comprehensive update of the status of this active field of research. Here is a list of the scientific topics that will be treated:

  • Formation and early evolution of brown dwarfs
  • Angular momentum and disk evolution in very low mass systems
  • Large scale surveys
  • Deep surveys
  • Brown dwarfs in binary systems
  • The lower end of the IMF
  • Planets around brown dwarfs
  • Ultracool atmospheres
  • Spectroscopy of brown dwarfs
  • Time domain phenomena in brown dwarfs: activity and weather
  • Oncoming and future projects in the substellar world
  • The brown dwarfs-exoplanet connection

1st Doha International Astronomy Conference: “Gravitational Microlensing – 101 years from theory to practice”

1st Doha International Astronomy Conference: “Gravitational Microlensing – 101 years from theory to practice” – 2013 marks the 101st anniversary of Einstein’s notebook entry in which he first discussed the transient brightening of an observed distant star caused by the bending of light due to the gravitational field of an intervening foreground star – a phenomenon now commonly known as ‘gravitational microlensing’. Continua a leggere 1st Doha International Astronomy Conference: “Gravitational Microlensing – 101 years from theory to practice”