#astronomy Astro Information: Planet-eating Stars and an Unintended Brown Dwarf – Sky & Telescope

September 4, 2021 - Comment

An Unintended Discovery The transferring object within the backside left nook of this animation of NEOWISE photos is a brown dwarf formally named WISEA J153429.75-104303.three and nicknamed “The Accident.”NASA / JPL-Caltech / Dan Caselden A citizen scientist has inadvertantly found a peculiar brown dwarf, formally referred to as WISEA J153429.75-104303.three — however nicknamed “The Accident.”


An Unintended Discovery

Nearby brown dwarf moving through stellar fieldThe transferring object within the backside left nook of this animation of NEOWISE photos is a brown dwarf formally named WISEA J153429.75-104303.three and nicknamed “The Accident.”
NASA / JPL-Caltech / Dan Caselden

A citizen scientist has inadvertantly found a peculiar brown dwarf, formally referred to as WISEA J153429.75-104303.three — however nicknamed “The Accident.”

Brown dwarfs, typically dubbed “failed stars,” radiate largely infrared relatively than seen mild. However whereas The Accident is brilliant at some infrared wavelengths, it is surprisingly faint at others. Its brightness throughout wavelengths, or spectrum, did not match that of greater than 2,000 brown dwarfs already recognized — in reality, that is why the thing slipped by preliminary searches.

Citizen scientist Dan Caselden, a pc safety researcher who enjoys participating with NASA’s Yard Worlds: Planet 9 undertaking, discovered the brown dwarf by — you guessed it — accident. He had created his personal program to seek out objects transferring throughout the body. He was particularly in search of these whose colours matched these of recognized brown dwarfs. However whereas he was taking a look at a kind of, he noticed The Accident flitting by.

Davy Kirkpatrick (Caltech) and colleagues revealed a follow-up research on the thing in Astrophysical Journal Letters. Based mostly on extra observations, they recommend that not solely has this brown dwarf cooled off, it is had plenty of time to take action — 10 billion to 13 billion years, they estimate. Consequently, it might need shaped earlier than there was a lot methane about; methane is what provides different brown dwarfs their attribute spectrum.

The group writes that the James Webb Area Telescope may present knowledge to verify or deny the shortage of methane, offering “verification, refutation, or additional befuddlement.”

Learn extra in NASA’s press launch.

Some Stars Eat Their Personal

Sibling stars ought to look alike, however some Solar-like stars that had been born in the identical fuel cloud as their companions present surprising variations — maybe as a result of some stars eat their very own planets.

Star with planetWithin the chaos of planet formation, some Solar-like stars might engulf their planets.ESA / ATG medialab

To know these chemical variations, Lorenzo Spina (INAF, Italy; Monash College and ASTRO-3D, Australia) led a group in analyzing pairs of Solar-like stars. In Nature Astronomy, they report that in 33 of 107 pairs, one of many stars has extra iron than anticipated (the opposite stellar pairs are all chemically equivalent). Iron is a refractory aspect that may survive engulfment by a star, and it is available in rocky planet cores.

Moreover, the celebrities with greater iron abundances additionally had extra lithium. Stars destroy lithium in fusion reactions, however lithium is plentiful in planets, so this discovering additionally helps the planet-engulfment situation.

Based mostly on the pattern, Spina’s group discovered that a couple of quarter of Solar-like stars eat from their very own planetary buffet, talking to the chaos — and carnage — of planet formation.

Learn extra from Spina at The Dialog.

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