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    ‘Monster’ Planet discovery challenges Formation Theory

    October 31, 2017, Categories  Uncategorized

    This is an artist's impression of the cool red star above NGTS-1b. Credit: University of Warwick/Mark Garlick

    This is an artist’s impression of the cool red star above NGTS-1b. Credit: University of Warwick/Mark Garlick

    A giant planet, which should not exist according to planet formation theory, has been discovered around a distant star. The existence of the ‘monster’ planet, ‘NGTS-1b’, challenges theories of planet formation which state that a planet of this size could not be formed around such a small star. According to these theories, small stars can readily form rocky planets but do not gather enough material together to form Jupiter-sized planets.

    ‘NGTS-1b’ however, is a ‘gas giant’ – due to its size and temperature, the planet is known as a ‘hot Jupiter’, a class of planets that are at least as large as our solar system’s very own Jupiter, but with around 20% less mass...

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    Spontaneous ‘Dust Traps:’ Astronomers discover a missing link in planet formation

    March 1, 2017, Categories  Astronomy/Space

    1. Stages of the formation mechanism for dust traps. The central star is depicted as yellow, surrounded by the protoplanetary disk, here shown in blue. The dust grains make up the band running through the disk. In the first stage, the dust grains grown in size, and move inwards towards the central star. The now pebble-sized larger grains (in the second panel) then pile up and slow down, and in the third stage the gas is pushed outwards by the back-reaction, creating regions where dust accumulates, the so-called dust traps. The traps then allow the pebbles to aggregate to form planetesimals, and eventually planet-sized worlds. Credit: © Volker Schurbert. Click for a full size image 2. An image of a protoplanetary disk, made using results from the new model, after the formation of a spontaneous dust trap, visible as a bright dust ring. Gas is depicted in blue and dust in red. Credit: Jean-Francois Gonzalez. Click for a full size image

    1. Stages of the formation mechanism for dust traps. The central star is depicted as yellow, surrounded by the protoplanetary disk, here shown in blue. The dust grains make up the band running through the disk. In the first stage, the dust grains grown in size, and move inwards towards the central star. The now pebble-sized larger grains (in the second panel) then pile up and slow down, and in the third stage the gas is pushed outwards by the back-reaction, creating regions where dust accumulates, the so-called dust traps. The traps then allow the pebbles to aggregate to form planetesimals, and eventually planet-sized worlds. Credit: © Volker Schurbert. Click for a full size image
    2...

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    Rings around Young Star suggest Planet Formation in progress

    December 12, 2016, Categories  Astronomy/Space

    An ALMA image of the star HD 163296 and its protoplanetary disk as seen in dust. New observations suggested that two planets, each about the size of Saturn, are in orbit around the star. These planets, which are not yet fully formed, revealed themselves in the dual imprint they left in both the dust and the gas portions of the star’s protoplanetary disk. (Credit: ALMA [ESO/NAOJ/NRAO]/Andrea Isella/B. Saxton [NRAO/AUI/NSF]) - See more at: http://news.rice.edu/2016/12/12/rings-around-young-star-suggest-planet-formation-in-progress/#sthash.pbHZ2cMD.dpuf

    An ALMA image of the star HD 163296 and its protoplanetary disk as seen in dust. New observations suggested that two planets, each about the size of Saturn, are in orbit around the star. These planets, which are not yet fully formed, revealed themselves in the dual imprint they left in both the dust and the gas portions of the star’s protoplanetary disk. (Credit: ALMA [ESO/NAOJ/NRAO]/Andrea Isella/B. Saxton [NRAO/AUI/NSF])

    Rice University astronomers and colleagues have for the first time mapped gases in 3 dark rings around a distant star. The rings mark spaces where planets are thought to have formed from dust and gas around the star...

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    Stellar Outburst brings Water Snowline around a Young Star into view

    July 14, 2016, Categories  Astronomy/Space

    This artist's impression of the water snowline around the young star V883 Orionis, as detected with ALMA. Credit: A. Angelich (NRAO/AUI/NSF)/ALMA (ESO/NAOJ/NRAO)

    This artist’s impression of the water snowline around the young star V883 Orionis, as detected with ALMA. Credit: A. Angelich (NRAO/AUI/NSF)/ALMA (ESO/NAOJ/NRAO)

    A violent outburst by the young star V883 Orionis has given astronomers their first view of a water “snowline” in a protoplanetary disk – the transition point around the star where the temperature and pressure are low enough for water ice to form. An abrupt increase in the brightness of the star “flash heated” the inner portion of the disk, pushing the water snowline out much farther than normal, enabling astronomers to image it with ALMA. Under normal conditions, the water snowline would be much too close to the protostar to observe directly, even with ALMA’s remarkable resolution.

    Typically, heat from a young Sun-like star preve...

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