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Thread: Disintegrating Planets - some recent news

  1. #91
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    And an old thread created on CQ that directly related to planetary engulfment and stellar pollution as a result, regarding van Maanen 2, the nearby white dwarf.

    https://forum.cosmoquest.org/showthr...anetary-system
    Do good work. —Virgil Ivan "Gus" Grissom

  2. #92
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    Quote Originally Posted by Noclevername View Post
    The name Dagon was old long before Lovecraft was ever born. https://en.wikipedia.org/wiki/Dagon
    It is still wise for us not to tempt the Ancient Ones. However, we did name a big section of Pluto after Cthulhu, I believe.
    Do good work. —Virgil Ivan "Gus" Grissom

  3. #93
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    Gas giant will be engulfed by its red-giant star in 800 million years.

    https://arxiv.org/abs/2005.00272
    TESS Asteroseismic Analysis of the Known Exoplanet Host Star HD 222076
    Chen Jiang, Timothy R. Bedding, Keivan G. Stassun, Dimitri Veras, Enrico Corsaro, Derek L. Buzasi, Przemysław Mikołajczyk, Qian-sheng, Zhang, Jian-wen, Ou, Tiago L. Campante, Thaíse S. Rodrigues, Benard Nsamba, Diego Bossini, Stephen R. Kane, Jia Mian Joel Ong, Mutlu Yıldız, Zeynep Çeiik Orhan, Sibel Örtel, Tao Wu, Xinyi Zhang, Tanda Li, Sarbani Basu, Margarida S. Cunha, Jørgen Christensen-Dalsgaard, William J. Chaplin
    [Submitted on 1 May 2020]
    The Transiting Exoplanet Survey Satellite (TESS) is an all-sky survey mission aiming to search for exoplanets that transit bright stars. The high-quality photometric data of TESS are excellent for the asteroseismic study of solar-like stars. In this work, we present an asteroseismic analysis of the red-giant star HD 222076 hosting a long-period (2.4 yr) giant planet discovered through radial velocities. Solar-like oscillations of HD 222076 are detected around 203 μHz by TESS for the first time. Asteroseismic modeling, using global asteroseismic parameters as input, yields a determination of the stellar mass (M⋆ = 1.12 ± 0.12 M⊙), radius (R⋆ = 4.34 ± 0.21R⊙), and age (7.4 ± 2.7Gyr), with precisions greatly improved from previous studies. The period spacing of the dipolar mixed modes extracted from the observed power spectrum reveals that the star is on the red-giant branch burning hydrogen in a shell surrounding the core. We find that the planet will not escape the tidal pull of the star and be engulfed into it within about 800 Myr, before the tip of the red-giant branch is reached.
    Do good work. —Virgil Ivan "Gus" Grissom

  4. #94
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    Brief description of a blistering-hot disintegrating gas giant, our pal KELT-9b.

    https://ui.adsabs.harvard.edu/abs/20...4727K/abstract
    Eclipses of a Scalding Hot Planet
    Kohler, Susanna
    AAS Nova Highlight, 25 Jan 2019, id.4727
    Pub Date: February 2019
    What's the atmosphere like on the hottest planet weve ever discovered? A new study suggests this toasty world may also be cloudless. More than two decades ago, the discovery of the first hot Jupiters--gas giant exoplanets that orbit extremely close to their host stars--signaled that other solar systems may host very different planets than our own. Since then, we've discovered a whole zoo of unusual planets including ever hotter Jupiters. Thus far, Kelt-9b holds the record. This scalding giant orbits once every 1.49 days while its 10,000-K host blasts it with ultraviolet radiation. Its dayside temperature (Kelt-9b is tidally locked, so the same side always faces its host) is somewhere between 4,000 and 4,600 K, which is hotter than many stars. Under these extreme conditions, what is Kelt-9bs atmosphere like? Is it similar to its slightly cooler hot-Jupiter cousins? Or do the extreme temperatures lead to unusual features?
    Do good work. —Virgil Ivan "Gus" Grissom

  5. #95
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    Gaseous iron discovered in scalding atmosphere of our buddy, KELT-9b.

    https://phys.org/news/2020-05-iron-e...tmosphere.html
    Do good work. —Virgil Ivan "Gus" Grissom

  6. #96
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    Some white dwarfs with metal pollution have planetary bodies near their tidal disruption limits. How did this happen?

    https://arxiv.org/abs/2005.05977
    High-eccentricity migration of planetesimals around polluted white dwarfs
    Christopher E. O'Connor, Dong Lai
    [Submitted on 12 May 2020]
    Several white dwarfs with atmospheric metal pollution have been found to host small planetary bodies (planetesimals) orbiting near the tidal disruption radius. We study the physical properties and dynamical origin of these bodies under the hypothesis that they underwent high-eccentricity migration from initial distances of several astronomical units. We examine two plausible mechanisms for orbital migration and circularization: tidal friction and ram-pressure drag in a compact disc. For each mechanism, we derive general analytic expressions for the evolution of the orbit that can be rescaled for various situations. We identify the physical parametres that determine whether a planetesimal's orbit can circularize within the appropriate time-scale and constrain these parametres based on the properties of the observed systems. For tidal migration to work, an internal viscosity similar to that of molten rock is required, and this may be naturally produced by tidal heating. For disc migration to operate, a minimal column density of the disc is implied; the inferred total disc mass is consistent with estimates of the total mass of metals accreted by polluted WDs.
    Do good work. —Virgil Ivan "Gus" Grissom

  7. #97
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    The disintegrating main-belt asteroid 6478 Gault, tail and all, are the subject of this paper.

    https://arxiv.org/abs/2005.07270
    Broadband photometry of asteroid 6478 Gault: activity and morphology
    S. Borysenko, A. Baransky, A. Simon, V. Vasylenko
    [Submitted on 14 May 2020]
    We present the results of short observational program for asteroid 6478 Gault with using of V and R Johnson filters realized at the Kyiv Comet Station during January-April 2019. Color indices and distribution of brightness in the comet-like tail were calculated. We made a comparative analysis of circumstances of the asteroid 6478 Gault activity with others morphologically similar active Main Belt asteroids.
    Do good work. —Virgil Ivan "Gus" Grissom

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