Temperamental stars can destroy our view of thousands of exoplanets, Hubble Telescope Finds

A new study has revealed that temperament stars that light up and weak for just a few hours can be distorting astronomers’ views on thousands of planets beyond the solar system.

The team behind this research reached this conclusion by studying 20 extrasolar planets or “Exoplanets“When they crossed, or” transferred “, faces of their parent stars by means Hubble Space Telescope. This revealed that starlight fluctuations caused by warmer and colder regions on the stars’ surfaces were more responsible for distorting interpretations of The exoplanet atmosphere than before.

The team found to its surprise that the information of about half of the 20 planets they studied, which stretched from Neptune -like worlds to inflated Hot Jupiter Planets were affected by their host star’s change. This is a worrying development because if these variations in stellar brightness are not reported, researchers can get a number of things about exoplanets errors, including their size, temperature and the composition of their atmospheres.

“These results were a surprise – we found more star pollution of our data than we expected. This is important for us to know,” said Team Leader and University College of London (UCL) researcher Arianna Saba in a statement sent to space. com. “By refining our understanding of how stars variation can affect our interpretations of exoplanets, we can improve our models and utilize the much larger data methods to get from assignments including James Webb Space Telescope (Jwst), Ariel and Twinkle. “

Two cylindrical spaceships pointed to a black -and -white striped orb in space, floating near a larger orange orb

Artwork that shows space telescopes that examines a planet when it transfers its star. Do they get contaminated data? (Image Credit: Alexandra Thompson)

Some stars blow hot and cold

Transit is a very important element in the exoplanet science.

As planets pass in front of their parent stars seen from the earth they cause a Tiny dip in the amount of starlight We get from these stars. These dip can be used to detect a revolving planet, and the time between dip in the light can be used to help researchers decide how long it takes the recently discovered world to revolve its star.

In addition, analyzing the starlight that passes through the atmosphere on a planet can tell researchers the composition of that atmosphere. This is possible because elements absorb light at different characteristic wavelengths. Thus, as Starlight passes through a planetary atmosphere, the elements of the atmosphere leave their fingerprints in that light.

Researchers read these chemical fingerprints using a method called ‘Spectroscopy. “

But if researchers read starlight errors, data on planetary atmospheres and even some exoplanet can be made by the transit method.

An illustration of an exoplanet PDS 70B wrapped in its prenatal cocoon.

An illustration of an exoplanet and its atmosphere as it transmits the face of its parent star (Image Credit: Robert Lea (created with Canva))

“We learn about exoplanets from the light from their host stars and it is sometimes difficult to cancel what is a signal from the star and what comes from the planet,” said team member and UCL researcher Alexandra Thompson. “Some stars can be described as” spotted ” – they have a larger proportion of colder regions, which are darker and warmer regions, which are lighter, on their surface. This is due to stronger magnetic activity.”

She explained that these lighter regions, or ‘faculés‘Ending more light, which means that if a planet passes in front of the hottest part of the star, this can lead to scientists overestimating how big the planet is. This is because the planet seems to block more of the star’s light, or the researchers can conclude that the planet is warmer than it actually is or that it has a denser atmosphere than it really did.

Thompson added that the reverse is also true: if the planet passes in front of a star’s cold place, it may have the effect to make that world look less than it actually is.

“The reduction of emitted light from one Star spot Can even mimic the effect of a planet passing in front of a star, which means that you think there may be a planet when there is none, “Thompson said.” This is why follow-up observations are so important to confirm the exoplanet discoveries. These variations from the star can also distort estimates of how much water vaporFor example, is in a planet’s atmosphere.

“This is because the variations can mimic or hide the signature of water vapor in the light pattern at different wavelengths that reach our telescopes.”

Some help from hubble

To investigate this potential effect, Saba, Thompson and colleagues turned to 20 years of Hubble observations collected using the long -term space telescope Space Telescope Imaging Spectrograph (STI) and Wide field camera 3 (WFC3) Instrument.

The team analyzed visible, almost infrared and almost ultraviolet wavelength data from 20 exoplanet systems in the same way to minimize bias that may be inherent in other studies.

Given models that stand for star variability and models that do not, the researchers looked at combinations of starlight and atmospheric models that best fit the data they recovered.

This revealed that 6 of the 20 exoplanets were better characterized by models that account for variations in their parental light. They also found that data on 6 other planets may have been somewhat damaged by light pollution from their host stars.

Over Electromagnetic spectrum The team considered, the distortions caused by star variability were much clearer in visible light and in almost UV radiation than in the infrared.

The team’s results have revealed two ways in which the variation in Starlight can affect exoplanet observations.

“One is to look at the overall shape of the spectrum – that is, the light pattern at different wavelengths that have passed through the planet from the star – to see if this can be explained by the planet alone or if Star activity needed, “finished Saba.” The second is to have two observations of the same planet in the optical region in the spectrum taken at different times.

“If these observations are very different, the probable explanation is varying star activity.”

The team’s results will be published in the Astrophysical Journal Supplement Series and are available as an oppression on the website for the research defense Arxiv.

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Temperamental stars can destroy our view of thousands of exoplanets, Hubble Telescope Finds

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