61 Virginis debris disc

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61 Virginis debris disc

Post by Lazarus on 13th June 2012, 2:33 am

Herschel imaging of 61 Vir: implications for the prevalence of debris in low-mass planetary systems

The Herschel observations imply a debris disc with inclination 77 degrees with an inner edge at ~30 AU. If the planets are coplanar with the disc, this would give true masses 2.6% greater than the minimum masses.

Regarding the planetary system:
Segransan et al. (in prep.) report 142 precise HARPS radial velocities (averaged values per night) of 61 Vir between JD = 53037 and 55948 that confirm the existence of the inner two planets, with parameters consistent with the values of Vogt et al. (2010) (i.e., a 5.1M planet at 0.05AU and a 18.2M planet at 0.218AU). However, the outermost planet (i.e., the 22.9M planet at 0.478AU) has not been confirmed in the HARPS data at this point.

Also the discovery of a debris disc at ~19 AU from HD 20794 (82 Eridani).
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Re: 61 Virginis debris disc

Post by tommi59 on 13th June 2012, 2:56 am

Planet d will go to unconfirmed catalog??
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Re: 61 Virginis debris disc

Post by Lazarus on 13th June 2012, 3:56 pm

Maybe. They do note there was a burst of activity on the star over part of the time range which could have affected their ability to find longer-period planets.

We shall see...
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Re: 61 Virginis debris disc

Post by Sirius_Alpha on 7th May 2017, 8:26 pm

ALMA observations of the multiplanet system 61 Vir: What lies outside super-Earth systems?
https://arxiv.org/abs/1705.01944

A decade of surveys has hinted at a possible higher occurrence rate of debris discs in systems hosting low mass planets. This could be due to common favourable forming conditions for rocky planets close in and planetesimals at large radii. In this paper we present the first resolved millimetre study of the debris disc in the 4.6 Gyr old multiplanet system 61 Vir, combining ALMA and JCMT data at 0.86 mm. We fit the data using a parametric disc model, finding that the disc of planetesimals extends from 30 AU to at least 150 AU, with a surface density distribution of millimetre sized grains with a power law slope of 0.1+1.1−0.8. We also present a numerical collisional model that can predict the evolution of the surface density of millimetre grains for a given primordial disc, finding that it does not necessarily have the same radial profile as the total mass surface density (as previous studies suggested for the optical depth), with the former being flatter. Finally, we find that if the planetesimal disc was stirred at 150 AU by an additional unseen planet, that planet should be more massive than 10 M⊕ and lie between 10-20 AU. Lower planet masses and semi-major axes down to 4 AU are possible for eccentricities ≫ 0.1.

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Re: 61 Virginis debris disc

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