The weird rectangular orbit of ‘hairpin flip’ exoplanet TIC 241249530. Video through Worldwide Gemini Observatory/ NOIRLab/ NSF/ AURA/ KPNO/ R. Proctor/ J. da Silva/ Spaceengine/ M. Zamani/ ESO/ L. Calçada/ M. Kornmesser/ N. Bartmann/ YouTube.
- Exoplanet TIC 241249530 has an especially elongated, cucumber-shaped orbit, making a pointy “hairpin flip” each time it approaches its star.
- The exoplanet additionally orbits its star backward, one other uncommon phenomenon amongst noticed transiting exoplanets.
- Scientists consider TIC 241249530 could also be transitioning right into a sizzling Jupiter, providing insights into planetary migration processes.
Exoplanet with an excessive orbit
We have a tendency to consider planets orbiting their stars in good, neat circles. However that’s not all the time true, not even in our personal solar system. Now, astronomers have discovered an exoplanet with a massively stretched-out orbit. A group of astronomers, led by Penn State College, said on July 17, 2024, that the orbit is probably the most excessive they’ve ever seen amongst exoplanets that transit their stars. The form of the orbit appears to be like extra like a cucumber than a circle. The ‘hairpin flip’ exoplanet makes a pointy flip each time it approaches the star.
Plus, the planet is orbiting its star backward, one thing additionally not usually seen. Though the planet is barely near its star for a part of its orbit, the observations present clues as to how hot Jupiter exoplanets kind.
The researchers published their peer-reviewed findings in regards to the uncommon planet in Nature on July 17, 2024.
‘Hairpin flip’ exoplanet has a stretched-out orbit
Astronomers have seen exoplanets with elongated orbits earlier than. However the orbit of this planet – TIC 241249530 – is actually stretched out. It appears to be like like a cucumber in form. So, each time the planet passes closest to its star, it makes a pointy “hairpin flip” of types. As co-author Suvrath Mahadevan at Penn State said:
We caught this huge planet making a pointy, hairpin flip throughout its shut passage to its star. Such extremely eccentric transiting planets are extremely uncommon, and it’s actually superb that we had been in a position to uncover probably the most eccentric one.
Some planets have near-perfect round orbits. Others are extra elongated. However this planet’s orbit is probably the most excessive seen but amongst exoplanets that transit – move in entrance of – their star as seen from Earth. Its orbital eccentricity – deviation from an ideal circle – is 0.94. For comparability, the dwarf planet Pluto’s orbit can also be extremely elongated, however solely has an orbital eccentricity of 0.25. Earth’s orbit is way more round, at solely 0.02.
For TIC 241249530, the researchers stated its extremely eccentric orbit means there could be wild temperature variations. When it’s farthest from its star, temperatures are about like a summer season’s day on Earth. However at its closest, it’s scorching sizzling.
The planet orbits its star about as soon as each six months.
Its orbit is backward, too
Not solely is the orbit of the “hairpin flip” exoplanet uncommon, however the planet is orbiting its star backward, too. Meaning it orbits within the path reverse to the rotation of the star, one thing else astronomers hardly ever see.
That, plus its bizarre elongated orbit, make it a uncommon discover for astronomers.
Will the ‘hairpin flip’ exoplanet develop into a sizzling Jupiter?
As well as, the invention suggests TIC 241249530 could also be within the strategy of turning into a sizzling Jupiter. Sizzling Jupiters are gas giant planets that orbit near their stars, and so, are extraordinarily sizzling. Scientists assume typically “regular” Jupiters migrate from extremely eccentric orbits towards tighter, extra round orbits round their stars.
Lead writer Arvind Gupta at Penn State and NOIRLab said:
Whereas we will’t precisely press rewind and watch the method of planetary migration in actual time, this exoplanet serves as a type of snapshot of the migration course of. Planets like this are arduous to search out and we hope it may assist us unravel the new Jupiter formation story.
Astronomers have found many sizzling Jupiters to date, however they’re additionally on the lookout for planets that can seemingly develop into sizzling Jupiters sooner or later. TIC 241249530 appears to suit that invoice, as Gupta famous:
Astronomers have been looking for exoplanets which are seemingly precursors to sizzling Jupiters, or which are intermediate merchandise of the migration course of, for greater than 20 years, so I used to be very stunned – and excited – to search out one.
Detection and characterization of TIC 241249530
The astronomers first discovered TIC 241249530 utilizing NASA’s Transiting Exoplanet Survey Satellite tv for pc (TESS) in January 2020. They then additional confirmed it with the WIYN 3.5-meter Telescope on the U.S. Nationwide Science Basis (NSF) Kitt Peak Nationwide Observatory (KPNO). The NN-EXPLORE Exoplanet and Stellar Speckle Imager (NESSI) on WIYN helped to dam out twinkling of the planet’s star attributable to Earth’s environment. Subsequent, the researchers used the NEID spectrograph and the Liveable Zone Planet Finder (HPF) spectrograph to research the sunshine coming from TIC 241249530.
The evaluation of the planet additionally confirmed it’s roughly 5 instances extra huge than Jupiter.
New document holder
TIC 241249530 now holds the document for transiting exoplanet with probably the most eccentric orbit. Beforehand, HD 80606b held that title.
Jason Wright is a professor of astronomy and astrophysics at Penn State and supervised the brand new research. He explained:
That is probably the most eccentric transiting planet recognized and can show to be as vital because the earlier document holder, HD 80606b, which likewise has a wacky orbit extremely misaligned with its host star’s spin. These two extremely eccentric planets have been “caught within the act” of evolving towards sizzling Jupiter standing. Like HD80606b, this planet is many instances Jupiter’s mass, suggesting this channel for forming sizzling Jupiters may be one solely probably the most huge planets can take.
Wright added:
We’re particularly occupied with what we will be taught in regards to the dynamics of this planet’s environment after it makes one in every of its scorchingly shut passages to its star. Telescopes like NASA’s James Webb Space Telescope have the sensitivity to probe the adjustments within the environment of this newly found exoplanet because it undergoes speedy heating, so there’s nonetheless way more for the group to be taught in regards to the exoplanet.
Scientists are excited in regards to the early outcomes for TIC 241249530 and about NEID general. Co-author Andrea Lin, a doctoral pupil at Penn State, stated:
It’s so thrilling to see such nice science popping out of NEID inside just some years of operations. We’re simply getting began and I’m trying ahead to seeing what we will accomplish sooner or later.
Backside line: Astronomers have discovered a “hairpin flip” exoplanet with an especially elongated orbit. It additionally orbits its star backward and will finally develop into a sizzling Jupiter.
Source: A hot-Jupiter progenitor on a super-eccentric retrograde orbit
Read more: The unexpected, exotic characteristics of hot Jupiters
