Baby planet (4/13/23)

Good afternoon, and happy Thursday. Elsewhere in the solar system, a tiny helicopter is readying for its 50th flight. Ingenuity, the chopper accompanying the Perseverance rover on its trek across the Martian surface, completed its nominal mission after only five flights and 30 days on the Red Planet. Keep on truckin’, Ginny.

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A planet is born

Through decades of observation and inference, scientists have whittled down to a rough understanding of how planets form. Within a loose disk of loose rock, gas, and dust spinning around a star, clumps begin to form, pulled together by gravitational forces. That fluid mass slowly condenses over the course of millions of years into a contained object: a new planet.

Rarely, though, have we spotted this process in action.

Now, researchers have confirmed finding a protoplanet—i.e., a young planet still in the process of forming—for the third time. The target of a study published this week in the Monthly Notices of the Royal Astronomical Society: Letters was spotted orbiting the star HD 169142, which is 374 light years from Earth.

Protoplanet hunting: Back in 2019, a team of researchers working with the European Southern Observatory’s Spectro-Polarimetric High-contrast Exoplanet Research (SPHERE) instrument, which is specifically dedicated to the search for planets orbiting other stars, turned its attention to HD 169142.

HD 169142 b, the protoplanet in question, is a bit farther from its host star than Neptune is from the Sun, or about 37 times as far as Earth is from our own hometown star. This separation allowed the astronomers to clearly distinguish the heat signature and movement of the protoplanet in observations. Observing these signatures, researchers found what they were looking for: a particularly hot, dynamic grouping of material.

Follow-up observations that split the light reflected by this object showed that it has a dense center obscured by a cloud of dust accumulated from the protoplanetary disk of loose material surrounding HD 169142.

Built different: The two protoplanets that have already been identified and confirmed look pretty different from this new finding—they’re surrounded by a whole lot less dust.

“It seems that we have captured it at a younger stage of its formation and evolution, as it is still completely buried in or surrounded by a lot of dust," said Valentin Christiaens, researcher at the PSILab of the University of Liège and one of the study’s authors.

Looking ahead: The research team intends to follow up the initial analysis of the SPHERE observations with additional scans using JWST. The space telescope’s delicate infrared instruments are better equipped to measure the precise signatures of the hot cloud surrounding the protoplanet.

Other News from the Cosmos

• ESA is targeting tomorrow to launch the JUICE (Jupiter Icy Moons Explorer) mission.

• The intensity of a certain dusty star variety correlates with the amount of material released into interstellar space.

• Dark matter has to be studied not through direct observation, but by how it affects observable material. A new measure of the universe’s “clumpiness” attempts to understand the distribution of dark matter across the cosmos.

• A disk of wind swirling around a neutron star as it pulls material from a nearby Sun-like star has been mapped by MIT astronomers.

• Upgrades to the Hydrogen Epoch of Reionization Array (HERA) telescope system in South Africa have doubled its sensitivity in their search for the “cosmic dawn,” the research team reports.

• Water arrived here on Earth under mysterious circumstances. A new study suggests a new potential explanation: interactions between a primordial hydrogen-rich atmosphere and a vast ocean of magma.

• A combination of astrometry and direct observation techniques revealed a gas giant exoplanet orbiting a nearby star.

The View from Space

A bright streak originally written off as an imaging flaw in a Hubble snapshot is actually a stream of stars formed in the 200,000 light year-long wake of a black hole careening through space.