(ORDO NEWS) — Astronomers from the University of Istanbul in Turkey have reported the discovery of a new short-period pulsating variable star while observing the field of exoplanet XO-2’s host star.
The detected object is most likely a Delta Scuti variable with a pulse period of less than one hour.
The discovery and study of variable stars can provide important clues about aspects of stellar structure and evolution.
The study of variable stars can also be useful for a better understanding of the scale of distances in the universe.
Delta Scuti stars are pulsating variables with spectral types A through F, named after the Delta Scuti variable in the constellation Scutum.
They exhibit radial and non-radial pulsations with periods ranging from 20 minutes to eight hours. Studying the pulsating behavior of the Delta Scuti variables can help us expand our knowledge of the interior of stars.
Now, a team of astronomers led by Mustafa Turan Sağlam has discovered a new variable that appears to be of the Delta Scuti type.
They used the Istanbul University Observatory’s 0.4-meter Schmidt-Cassegrain Telescope (IST40) to observe the host star of exoplanet XO-2 as part of a research program to study changes in transit times.
After that, complex follow-up photometric observations of the newfound star were carried out to confirm its variability.
“We present the discovery of a new variable in the field of the host star of exoplanet XO-2. The new variable was observed over 10 nights with various standard photometric filters in addition to white light observations,” the researchers say.
The period of pulsations of the new variable was approximately 0.95 hours, and its mass is estimated at 1.5-1.7 solar masses.
The variable was found to have spectral type A7 and an effective temperature of about 7501°C. These properties are typical of Delta Scuti stars.
Moreover, the shape of the light curves of the newly discovered variable and automated classification based on machine learning algorithms confirm the Delta Scuti scenario. According to astronomers’ calculations, the probability that this hypothesis is correct is about 78%.
The study also showed that the star under study has a luminosity of about 6.93 solar luminosities and an absolute magnitude in the V-band of about 2.76. The distance to this variable, based on data from ESA’s Gaia satellite, is estimated at about 5,613 light-years.
Summing up, the researchers noted that further observations of this variable are needed to finally confirm its nature and shed more light on the behavior of the pulsations.
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