# Disk and hints of a planet at HD 107146

## Disk and hints of a planet at HD 107146

A Resolved Ring of Debris Dust Around the Solar Analog HD 107146
http://arxiv.org/abs/0811.2713

S.A. Corder et al. wrote:We present resolved images of the dust continuum emission from the debris disk around the young (80-200 Myr) solar-type star HD 107146 with CARMA at $\lambda$1.3 mm and the CSO at $\lambda$350 $\mu$m. Both images show that the dust emission extends over an $\sim$10\arcsec diameter region. The high resolution (3\arcsec) CARMA image further reveals that the dust is distributed in a partial ring with significant decrease in flux inward of 97 AU. Two prominent emission peaks appear within the ring separated by $\sim$140 degrees in position angle. The morphology of the dust emission is suggestive of dust captured into a mean motion resonance, which would imply the presence of a planet at an orbital radius of $\sim$45-75 AU.

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Sirius_Alpha

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## Re: Disk and hints of a planet at HD 107146

If a slightly excessive bump is to be permitted…

ALMA observations of the debris disk around the young Solar Analog HD 107146
We present ALMA continuum observations at a wavelength of 1.25 mm of the debris disk surrounding the ∼100 Myr old solar analog HD 107146. The continuum emission extends from about 30 to 150 AU from the central star with a decrease in the surface brightness at intermediate radii. We analyze the ALMA interferometric visibilities using debris disk models with radial profiles for the dust surface density parametrized as i) a single power-law, ii) a single power-law with a gap, and iii) a double power-law. We find that models with a gap of radial width ∼8 AU at a distance of ∼80 AU from the central star, as well as double power-law models with a dip in the dust surface density at ∼70 AU provide significantly better fits to the ALMA data than single power-law models. We discuss possible scenarios for the origin of the HD 107146 debris disk using models of planetesimal belts in which the formation of Pluto-sized objects trigger disruptive collisions of large bodies, as well as models which consider the interaction of a planetary system with a planetesimal belt and spatial variation of the dust opacity across the disk. If future observations with higher angular resolution and sensitivity confirm the fully-depleted gap structure discussed here, a planet with a mass of approximately a few Earth masses in a nearly circular orbit at ∼80 AU from the central star would be a possible explanation for the presence of the gap.
A very interesting read for anyone with so much as a passing interest in debris disk studies.

Although only more sensitive and higher angular resolution observations can possibly confirm the presence of a gap in the HD 107146 debris disk, this analysis shows the potential of probing (indirectly) with ALMA the presence of terrestrial planets (and more massive
planets) at wide separations and embedded in planetesimal disks. Terrestrial planets are still well beyond the reach of direct imaging techniques. In the case of HD 107146, upper limits of ∼ 10 − 13 MJup at distances >∼ 15 AU from the central star have been obtained
by high-contrast imaging in the near IR.

Shellface
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## Re: Disk and hints of a planet at HD 107146

http://spaceref.com/astronomy/swarms-of-pluto-size-objects-kick-up-dust-around-sun-like-star.html

Swarms of Pluto-size Objects Kick Up Dust Around Sun-like Star

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) may have detected the dusty hallmarks of an entire family of Pluto-size objects swarming around an adolescent version of our own Sun.
By making detailed observations of the protoplanetary disk surrounding the star known as HD 107146, the astronomers detected an unexpected increase in the concentration of millimeter-size dust grains in the disk's outer reaches. This surprising increase, which begins remarkably far -- about 13 billion kilometers -- from the host star, may be the result of Pluto-size planetesimals stirring up the region, causing smaller objects to collide and blast themselves apart.

Led_Zep
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