Newfound baby exoplanet photographed from more than 400 light-years away

Exoplanets that can be directly imaged are a smaller population compared to the more than 4800 confirmed now. Here are some notes from me on this exoplanet, 2M0437b after digging into the arXix paper and other reports out now.

Reference paper cited, Zodiacal Exoplanets in Time (ZEIT) XII: A Directly-Imaged Planetary-Mass Companion to a Young Taurus M Dwarf Star,, 16-Oct-2021. "We report the discovery of a resolved (0".9) substellar companion to a member of the 1-5 Myr Taurus star-forming region. The host star (2M0437) is a single mid-M type (Teff≈3100K) dwarf with a position, space motion, and color-magnitude that support Taurus membership, and possible affiliation with a ∼2.5 Myr-old sub-group..."

An exoplanet resolved at 0.9 arcsecond from the host star is cool :) My telescopes can resolve to about 1.5 arcsecond or so, depending upon seeing conditions in the atmosphere. The 19 page arXiv paper indicates the distance is 128.1 pc. This is nearly 418 LY. The eu exoplanet site has it listed now,

Using exoplanet mass 4 Mjup, a=118 au, e=0, host star mass 0.18 Msun, P=2.9898E+03 years or about 2990 years for a complete orbit around the host star. My note. The report indicates there is no protoplanetary disk observed in this system. "By analyzing the light from this planet we can say something about its composition, and perhaps where and how it formed in a long-vanished disk of gas and dust around its host star."

The host star is considered to be about 2.5 million years old. The exoplanet is a larger, Jovian type planet in an orbit far from the host star, at least 118 au distance. No protoplanetary disk is seen and the exoplanet does challenge formation models like accretion from a spinning, protoplanetary disk with enough gas and solids to form the planet. The measured temperature for this exoplanet is 1450 K,, this 1177 C temperature. The hot temperature reported does fit with a young exoplanet that still glows hot from its recent origin, unlike Jupiter in our solar system that orbits near 5.204 au from the Sun. Using the MMSN for the total gas and dust around the host star with 0.0165 Msun reported, is about 55 earth masses. This is not enough to explain the origin of a 4 Mjup exoplanet orbiting a very small star, perhaps near 0.17 solar mass. If a protoplanetary disk did exist, it must be more massive than the MMSN value used for the host star mass. That is about 10^-4 mass of star for a protoplanetary disk with 1% dust and 99% gas content.

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