Young planetary system around HD 163296

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Young planetary system around HD 163296

Post by Led_Zep on 15th December 2016, 5:25 pm

http://www.almaobservatory.org/en/press-room/press-releases/1082-alma-finds-compelling-evidence-for-pair-of-infant-planets-around-young-star

ALMA Finds Compelling Evidence for Pair of Infant Planets around Young Star

New observations with the Atacama Large Millimeter/submillimeter Array (ALMA) contain compelling evidence that two newborn planets, each about the size of Saturn, are in orbit around a young star known as HD 163296. These planets, which are not yet fully formed, revealed themselves by the dual imprint they left in both the dust and the gas portions of the starís protoplanetary disk.


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Re: Young planetary system around HD 163296

Post by Edasich on 17th December 2016, 4:38 am

The two Saturn-mass protoplanets of HD 163296 have been added to EPE:

http://exoplanet.eu/catalog/hd_163296_b/
http://exoplanet.eu/catalog/hd_163296_c/

I don't understand why many other transiting and non transiting validated planets haven't been added. Updates have turned quite odd at EPE lately.
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HD 163296 - Two long-period gas giants from ALMA gas disk kinematics

Post by Sirius_Alpha on 28th May 2018, 8:37 pm

A Kinematical Detection of Two Jupiter Mass Planets
https://arxiv.org/abs/1805.10290

We present the first kinematical detection of embedded protoplanets within a protoplanetary disk. Using archival ALMA observations of HD 163296, we demonstrate a new technique to measure the rotation curves of CO isotopologue emission to sub-percent precision relative to the Keplerian rotation. These rotation curves betray substantial deviations caused by local perturbations in the radial pressure gradient, likely driven by gaps carved in the gas surface density by Jupiter-mass planets. Comparison with hydrodynamic simulations shows excellent agreement with the gas rotation profile when the disk surface density is perturbed by two Jupiter mass planets at 83 au and 137 au. As the rotation of the gas is dependent on the pressure of the total gas component, this method provides a unique probe of the gas surface density profile without incurring significant uncertainties due to gas-to-dust ratios or local chemical abundances which plague other methods. Future analyses combining both methods promise to provide the most accurate and robust measures of embedded planetary mass. Furthermore, this method provides a unique opportunity to explore wide-separation planets beyond the mm continuum edge and to trace the gas pressure profile essential in modelling grain evolution in disks.

A possible third planet may exist but they can't be particularly confident in that at this time.

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Re: Young planetary system around HD 163296

Post by Lazarus on 29th May 2018, 2:12 am

Also in today's batch of papers:

Pinte et al. "Kinematic evidence for an embedded protoplanet in a circumstellar disc"
https://arxiv.org/abs/1805.10293

They analyse the ALMA data for the same system and come to the conclusion that there is a single 2 Jupiter-mass planet at 260 AU.

Same data, different result
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Re: Young planetary system around HD 163296

Post by Led_Zep on 13th June 2018, 10:38 am

ESO press release :

http://www.eso.org/public/news/eso1818/

ALMA Discovers Trio of Infant Planets around Newborn Star

Two independent teams of astronomers have used ALMA to uncover convincing evidence that three young planets are in orbit around the infant star HD 163296. Using a novel planet-finding technique, the astronomers identified three disturbances in the gas-filled disc around the young star: the strongest evidence yet that newly formed planets are in orbit there. These are considered the first planets to be discovered with ALMA
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Re: Young planetary system around HD 163296

Post by Sirius_Alpha on 19th November 2018, 11:43 pm

Multi-epoch Direct Imaging and Time-Variable Scattered Light Morphology of the HD 163296 Protoplanetary Disk
https://arxiv.org/abs/1811.07785

We present H-band polarized scattered light imagery and JHK high-contrast spectroscopy of the protoplanetary disk around HD 163296 observed with the HiCIAO and SCExAO/CHARIS instruments at Subaru Observatory. The polarimetric imagery resolve a broken ring structure surrounding HD 163296 that peaks at a distance along the major axis of 0.65 (66 AU) and extends out to 0.98 (100 AU) along the major axis. Our 2011 H-band data exhibit clear axisymmetry, with the NW- and SE- side of the disk exhibiting similar intensities. Our data are clearly different than 2016 epoch H-band observations from VLT/SPHERE that found a strong 2.7x asymmetry between the NW- and SE-side of the disk. Collectively, these results indicate the presence of time variable, non-azimuthally symmetric illumination of the outer disk. Based on our 3D-MCRT modeling of contemporaneous IR spectroscopic and H-band polarized intensity imagery of the system, we suggest that while the system could plausibly host an inclined inner disk component, such a component is unlikely to be responsible for producing the observed time-dependent azimuthal variations in the outer scattered light disk of the system. While our SCExAO/CHARIS data are sensitive enough to recover the planet candidate identified from NIRC2 in the thermal IR, we fail to detect an object with a corresponding JHK brightness estimated from the atmospheric models of Baraffe et al. 2003. This suggests that the candidate is either fainter in JHK bands than model predictions, possibly due to extinction from the disk or atmospheric dust/clouds, or that it is an artifact of the dataset/data processing. Our SCExAO/CHARIS data lower the IR mass limits for planets inferred at larger stellocentric separations; however, these ALMA-predicted protoplanet candidates are currently still consistent with direct imaging constraints.
(emphasis mine)

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