Possible image of an exoplanet next to Beta Pictoris

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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Lazarus on 2nd May 2014, 9:58 am

Also from a read-through of the paper, it looks like at least some superjovian planets might spin very quickly indeed:
Over the next hundreds of millions of years the planet is expected to cool down and shrink to the size of Jupiter. If its angular moment is preserved during this process, the planet should spin up to Vspin ~ 40 km sec-1, depending on possible changes in its internal structure, decreasing its length of day to ~3 hours.
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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Sirius_Alpha on 17th July 2014, 9:08 pm

The First H-band Spectrum of the Massive Gas Giant Planet beta Pictoris b with the Gemini Planet Imager
http://arxiv.org/abs/1407.4469

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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Lazarus on 18th July 2014, 2:31 am

Also:

Bonnefoy et al. "Physical and orbital properties of Beta Pictoris b"
http://arxiv.org/abs/1407.4001
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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Lazarus on 11th September 2014, 5:20 pm

Kong et al. (2014) "The shape, internal structure and gravity of the fast spinner β Pictoris b"
http://mnrasl.oxfordjournals.org/content/445/1/L26

For masses 6–16 MJ, the eccentricity of the oblate spheroid ε ranges from 0.36928–0.23398, which correspond to oblateness values 0.071–0.028.

Assuming it shrinks and spins up to 1 Jupiter radius and 3 hour rotation, the range of ε ends up as 0.45552–0.29422, which gives oblateness values of 0.110–0.044.

For comparison, Saturn has an oblateness 0.098.
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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Sirius_Alpha on 22nd October 2014, 1:27 pm

Two Families of Comets Found Around Nearby Star
http://www.eso.org/public/news/eso1432/

Link to paper.
http://www.eso.org/public/archives/releases/sciencepapers/eso1432/eso1432a.pdf



The HARPS instrument at ESO’s La Silla Observatory in Chile has been used to make the most complete census of comets around another star ever created. A French team of astronomers has studied nearly 500 individual comets orbiting the star Beta Pictoris and has discovered that they belong to two distinct families of exocomets: old exocomets that have made multiple passages near the star, and younger exocomets that probably came from the recent breakup of one or more larger objects. The new results will appear in the journal Nature on 23 October 2014.

Moreover, the orbits of these comets (eccentricity and orientation) are exactly as predicted for comets trapped in orbital resonance with a massive planet. The properties of the comets of the first family show that this planet in resonance must be at about 700 million kilometres from the star  — close to where the planet Beta Pictoris b was discovered.

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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Lazarus on 22nd October 2014, 4:35 pm

Nice. I seem to recall that there was previous work that suggested that there were two famillies of exocomets in the system, which was indeed used as a prediction of the presence of a planet before the discovery of Beta Pic b. Good to see it confirmed!
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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Led_Zep on 19th February 2015, 5:15 pm

http://hubblesite.org/newscenter/archive/releases/2015/06/full/

Astronomers have used NASA's Hubble Space Telescope to take the most detailed picture to date of a large, edge-on, gas-and-dust disk encircling the 20-million-year-old star Beta Pictoris.
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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Sirius_Alpha on 22nd August 2015, 1:52 am

β PICTORIS’ INNER DISK IN POLARIZED LIGHT AND NEW ORBITAL PARAMETERS FOR β PICTORIS b
http://arxiv.org/abs/1508.04787

They find a transit probability of ~0.06%, but note that it appears certain now that the planet's Hill sphere at least will transit, similar to the situation at J1407.

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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Led_Zep on 8th July 2016, 4:59 am

Slide from Davos meeting :

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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Lazarus on 8th July 2016, 1:30 pm

Pity, it was so close. But nevertheless a chance to see if there's something like the J1407 ring.
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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Sirius_Alpha on 19th July 2016, 8:45 pm

Paper.
The Orbit and Transit Prospects for β Pictoris b constrained with One Milliarcsecond Astrometry
http://arxiv.org/abs/1607.05272

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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Led_Zep on 1st March 2017, 10:38 pm

https://arxiv.org/abs/1703.00011

1 to 2.4 micron Near-IR spectrum of the Giant Planet β Pictoris b obtained with the Gemini Planet Imager

Using the Gemini Planet Imager (GPI) located at Gemini South, we measured the near-infrared (1.0-2.4 micron) spectrum of the planetary companion to the nearby, young star β Pictoris. We compare the spectrum obtained with currently published model grids and with known substellar objects and present the best matching models as well as the best matching observed objects. Comparing the empirical measurement of the bolometric luminosity to evolutionary models, we find a mass of 12.9±0.2 M Jup , an effective temperature of 1724±15 K, a radius of 1.46±0.01 R Jup , and a surface gravity of logg=4.18±0.01 [dex] (cgs). The stated uncertainties are statistical errors only, and do not incorporate any uncertainty on the evolutionary models. Using atmospheric models, we find an effective temperature of 1700−1800 K and a surface gravity of logg=3.5 -4.0 [dex] depending upon model. These values agree well with other publications and with "hot-start" predictions from planetary evolution models. Further, we find that the spectrum of β Pic b best matches a low-surface gravity L2± 1 brown dwarf. Finally comparing the spectrum to field brown dwarfs we find the the spectrum best matches 2MASS J04062677-381210 and 2MASS J03552337+1133437
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Re: Possible image of an exoplanet next to Beta Pictoris

Post by Led_Zep on 25th March 2017, 7:04 pm

Automatic translation of an article in french :
https://lagrange.oca.eu/fr/accueil-astep

Observation of β Pictoris since Antarctica: the adventure begins!

The first observations the star Beta Pictoris and planet from the Antarctic Concordia station continuously come to start.


With the arrival of the polar night in Antarctica, the star β Pic with ASTEP telescope observations come from start. It is observing a system of a very young star and his giant planet, to try to discover moons or rings and to the past, to solve a mystery: the change in brightness of the observed star in 1981 was due to the passage of the planet in front of its star? For the first time, as part of an international collaboration, a telescope will point this famous star continuously from March until September 2017. This is possible because this automatic telescope is located in the middle of the Antarctic continent, and it boasts a nearly continuous night during the austral winter. The first light of β Pic curves are very promising.
The star β Pic is famous: it's the first Star for which one could imagine a Protoplanetary disc in 1984. It is also around this star are deduced for the first time the presence of "exocometes". In 2008, a planet was discovered about 8 astronomical units from its star (roughly the distance from Saturn to the Sun). The study of this planet, β Pic b, and the disc of dust around the star, is a unique source of information to understand these very young systems and the formation of the planets. Follow-up imaging of the orbit of beta Pic b shows that this one will pass in front of its star (or almost) in summer 2017. This opportunity will never happen before 18 or 36 years. Detection of a transit (the planet exactly passing the star) would be a revolution in the field as it would for the first time to have all the physical characteristics of an Exoplanet that can give an image directly. It would also observe a disk around the star and the moons, rings, which has never been done! Photometric variations will be recorded. Perhaps to prove - they similar to strange photometric variations observed in 1981, and attributed in the 1990s either a planet, or comets. However, between April and September 2017, only the telescopes in Antarctica are well-placed to observe β Pic.
Thanks to the support of the french Polar Institute Paul Emile Victor (SJ), the University Côte d'Azur, the Observatory of the Cote d'Azur and the Lagrange laboratory have an automated telescope capable of observing this star continuously since the Antarctic Concordia station. This station managed by Italian and french Polar institutes is a permanent basis: it is inhabited also in winter, which allows monitoring of the instruments. ASTEP is a telescope of 40cm in diameter. He is able to observe in the harsh conditions of Antarctica: who have reached - 65 ° C and temperatures that can go down to-80 ° C in the heart of the austral winter. This telescope, which ran successfully from 2010 to 2014 has been reinstalled at Concordia end of 2016, motivated by an international collaboration including the University of Grenoble and the University of California, Berkeley (USA). The first curves of light come from us. They are of excellent quality. Although we have only a few hours of observations, we can already confirm that β Pic is a variable star and study its oscillations. His continuous monitoring will be instructive. The adventure begins!




First light from the star β Pic curves obtained by the telescope ASTEP
Since the Antarctic on 5, 6 and 7 March 2017. Curves clearly show the oscillations of the star
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