Turkish astronomers discovered ten new pulsating variable stars, including five Delta Scuti variables, by analyzing data from NASA’s Transiting Exoplanet Survey Satellite (TESS). The discovery is detailed in a paper published on the arXiv pre-print server on August 25.
Detecting and studying variable stars could provide important clues about stellar structure and evolution. The variable investigation could also aid in a better understanding of the universe’s distance scale. Delta Scuti and Gamma Doradus stars are two main-sequence A-F type pulsating variables.
Delta Scuti stars are pulsating variables with spectral types ranging from A0 to F5, named after the constellation Scutum’s Delta Scuti variable. They have radial and non-radial pulsations that last from 20 minutes to eight hours. The pulsation behavior of Delta Scuti variables could help us learn more about stellar interiors. Gamma Doradus stars are dwarf and/or sub-dwarf variables with spectral types A7-F5 and periods on the order of a day.
A team of astronomers led by FilizKahramanAlicavus of Turkey’s AnakkaleOnsekiz Mart University has discovered ten new pulsating variables by examining the TESS database.
“We present a portion of our northern TESS field research to discover unknown Delta Scuti type variables in this paper. (…) The TESS data was retrieved from the MAST [Barbara A. Mikulski Archive for Telescopes] archive. To find these types of variable stars, only SC [short cadence] TESS data were examined “The researchers wrote about it in their paper.
Alicavus’ team discovered five Delta Scuti stars, one Gamma Doradus variable, and four hybrid systems as a result. The new Delta Scuti variables, TIC 25537276, TIC 177422294, TIC 252554307, TIC 279874050, and TIC 370599803, have effective temperatures ranging from 6,812 to 7,394 K and bolometric luminosities ranging from 0.69 to 2.23 mag.
The only Gamma Doradus variable identified in the study is TIC 308447073. Its effective temperature is estimated to be 7,539 K, and its bolometric luminosity is about 2.69 mag.
TIC 367910480, TIC 395520454, TIC 400502366, and TIC 431375592 were assigned to the remaining four variables. Their effective temperatures range from 6,411 to 8,476 K. These stars have bolometric luminosities ranging from 0.27 to 3.25 mag. They were classified as hybrid variables because they exhibit both Delta Scuti and Gamma Doradus-type oscillations.
According to the researchers, they classified the ten variables based on the frequency spectra and pulsation constant values of these stars.
The astronomers wrote in their study, “The final pulsation type classification was made by considering the frequency ranges and pulsation constants of the stars.”