Monthly Archives: December 2013

Time magazine covers our results: finding a sub-stellar mass companion candidate in a nearby binary dwarf system


http://science.time.com/2013/12/17/very-sad-planet-orbits-very-sad-star/

More coverage:
http://www.spacedaily.com/reports/Nearby_failed_stars_may_harbor_planet_999.html

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Carnegie Observatories Press release: Nearby Failed Stars May Harbor Planet


http://obs.carnegiescience.edu/content/nearby-failed-stars-may-harbor-planet

Pasadena, CA— Astronomers, including Carnegie’s Yuri Beletsky, took precise measurements of the closest pair of failed stars to the Sun, which suggest that the system harbors a third, planetary-mass object.The research is published as a letter to the editor in Astronomy & Astrophysics available online at http://arxiv.org/abs/1312.1303.
Failed stars are known as brown dwarfs and have a mass below 8% of the mass of the Sun—not massive enough to burn hydrogen in their centers. This particular system, Luhman 16AB, was discovered earlier this year and is only 6.6 light-years away.
After the discovery announcement, several teams of astronomers, including the one with Beletsky, used a variety of telescopes to characterize the neighbouring couple.
After two-months of observations and extensive data analysis, Beletsky’s team, led by Henri Boffin of the European Southern Observatory (ESO), found that both objects have a mass between 30 and 50 Jupiter masses. By comparison, the Sun has a mass of about 1,000 Jupiter masses.
The two brown dwarfs are separated by about three times the distance between the Earth and the Sun. Binary brown dwarf systems are gravitationally bound and orbit about each other. Because these two dwarfs have so little mass, they take about 20 years to complete one orbit,” explained Beletsky.
The team used the FORS2 instrument on ESO’s Very Large Telescope at Paranal to image the brown dwarf couple in the best possible conditions, every 5 or 6 days over the period April 14, to June 22, 2013. Because of the instrument enabled the observers to make very precise measurements, the scientists were already able to detect tiny displacements of the two objects in their orbit during only this the two-month period.
The astronomers were able to measure the positions of the two brown dwarfs with ten times better accuracy than before and thereby detect even small perturbations of their orbit.
“We have been able to measure the positions of these two objects with a precision of a few milli-arcseconds,” said Boffin. “That is like a person in Paris being able to measure the position of someone in New York with a precision of 10 centimetres.”
The measurements were so fine that the astronomers were able to see some very small deviations from the expected motion of the two brown dwarfs around each other. The fact that the deviations appear correlated is a strong indication that a companion perturbs the motion of one of the two brown dwarfs. This companion is most likely a planetary-mass object, which has an orbital period between two months and a year.“Further observations are required to confirm the existence of a planet,” concludes Boffin. “But it may well turn out that the closest brown dwarf binary system to the Sun turns out to be a triple system!”
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The team is composed of Henri Boffin, Kora Muzic, Valentin Ivanov, Andrea Mehner, Jean-Philippe Berger, Julien Girard, and Dimitri Mawet (ESO, Chile), Dimitri Pourbaix (Université Libre de Bruxelles, Belgium), Rudy Kurtev (Universidad de Valparaiso, Chile), and Yuri Beletsky (Carnegie Observatories at Las Campanas Observatory, Chile).

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„Possible astrometric discovery of a substellar companion to the closest binary brown dwarf system WISE J104915.57-531906.1“, H.M.J. Boffin, D. Pourbaix, K. Muzic, V.D. Ivanov, R. Kurtev, Y. Beletsky, A. Mehner, J.P. Berger, J.H. Girard, D. Mawet (Astronomy and Astrophysics, in press)


Abstract: Using FORS2 on the Very Large Telescope, we have astrometrically monitored over a period of two months the two components of the brown dwarf system WISE J104915.57-531906.1, the closest one to the Sun. Our astrometric measurements – with a relative precision at the milli-arcsecond scale – allow us to detect the orbital motion and derive more precisely the parallax of the system, leading to a distance of 2.020+/-0.019 pc. The relative orbital motion of the two objects is found to be perturbed, which leads us to suspect the presence of a substellar companion around one of the two components. We also perform VRIz photometry of both components and compare with models. We confirm the flux reversal of the T dwarf.

A PDF is available here: http://arxiv.org/pdf/1312.1303v1

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Нова антология с българска фантастика и фентъзи: „За спасяването на света“, издателство „Човешката библиотека“


От съобщението за пресата:

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На 4 декември 2013 г., точно седем години след появата на „Последният еднорог“ на български език, излиза тринадесетата книга в поредица „Човешката библиотека“ (http://choveshkata.net/blog/): антологията „За спасяването на света“.

„За спасяването на света“ събира 48 разказа, новели и повести от 41 български автори и пет десетилетия. Тези близо 400 хиляди думи я правят най-мащабната антология в българската литература.

Мащабни са и темите на самите текстове – всеки от тях е подбран заради силата си да ни размисли, развълнува, навярно даже промени. „Спасяване“ и „свят“ се появяват буквално и метафорично, сериозно и с намигване.

В спасяването на света ръка си подават писатели със статус на съвременни класици – като Величка Настрадинова, Агоп Мелконян, Светослав Славчев, Любен Дилов; утвърдени имена – като Николай Теллалов, Йоан Владимир, Петър Кърджилов, Любомир П. Николов, Янчо Чолаков, Атанас П. Славов, Александър Карапанчев, Велко Милоев, Красимир Георгиев, Елена Павлова, Георги Малинов; и млади (но вече впечатляващи) творци – Димитър Риков, Красимира Стоева, Геновева Детелинова, Саша Александрова, Калоян Захариев. Голяма част от текстовете са награждавани в България и издавани по света.

„За спасяването на света“ е съвместно издание на фондация „Човешката библиотека“, Дружество на българските фантасти „Тера Фантазия“ и списание „Тера фантастика“. Антологията излиза в електронен и хартиен вариант. Електронният вариант се разпространява свободно на принципа „читателите плащат колкото и ако преценят“. Всички приходи се разпределят между творческите участници: автори, съставители, редактори, коректори, художници и оформители.

За повече: http://choveshkata.net/blog/?page_id=4075 и на poslednorog -в- gmail-точка-com

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Предговорът можете да прочетете на: http://choveshkata.net/blog/?page_id=4237

В антологията няма нови разкази. Съдържание е достъпно на: http://choveshkata.net/blog/?page_id=4076

И последно, ние с Киро участваме с разказа „Денят, в който вярата се завърна“, който през 2007 г. спечели първа на града в конкурса „Фантастика през 100 очи“ на издателство „Аргус“ (http://bgf.zavinagi.org/index.php/%D0%98%D0%B7%D0%B4%D0%B0%D1%82%D0%B5%D0%BB%D1%81%D1%82%D0%B2%D0%BE_%D0%90%D1%80%D0%B3%D1%83%D1%81).

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