Date:

Astronomers Accurately Measure the Temperature of Red Supergiant Stars

Red supergiants are a class of star that end their lives in supernova explosions. Their lifecycles are not fully understood, partly due to difficulties in measuring their temperatures. For the first time, astronomers develop an accurate method to determine the surface temperatures of red supergiants.

Stars come in a wide range of sizes, masses and compositions. Our sun is considered a relatively small specimen, especially when compared to something like Betelgeuse which is known as a red supergiant. Red supergiants are stars over nine times the mass of our sun, and all this mass means that when they die they do so with extreme ferocity in an enormous explosion known as a supernova, in particular what is known as a Type-II supernova.

- Advertisement -

Type II supernovae seed the cosmos with elements essential for life; therefore, researchers are keen to know more about them. At present there is no way to accurately predict supernova explosions. One piece of this puzzle lies in understanding the nature of the red supergiants that precede supernovae.

Despite the fact red supergiants are extremely bright and visible at great distances, it is difficult to ascertain important properties about them, including their temperatures. This is due to the complicated structures of their upper atmospheres which leads to inconsistencies of temperature measurements that might work with other kinds of stars.

“In order to measure the temperature of red supergiants, we needed to find a visible, or spectral, property that was not affected by their complex upper atmospheres,” said graduate student Daisuke Taniguchi from the Department of Astronomy at the University of Tokyo. “Chemical signatures known as absorption lines were the ideal candidates, but there was no single line that revealed the temperature alone. However, by looking at the ratio of two different but related lines — those of iron — we found the ratio itself related to temperature. And it did so in a consistent and predictable way.”

Taniguchi and his team observed candidate stars with an instrument called WINERED which attaches to telescopes in order to measure spectral properties of distant objects. They measured the iron absorption lines and calculated the ratios to estimate the stars’ respective temperatures. By combining these temperatures with accurate distance measurements obtained by the European Space Agency’s Gaia space observatory, the researchers calculated the stars luminosity, or power, and found their results consistent with theory.

- Advertisement -

“We still have much to learn about supernovae and related objects and phenomena, but I think this research will help astronomers fill in some of the blanks,” said Taniguchi. “The giant star Betelgeuse (on Orion’s shoulder) could go supernova in our lifetimes; in 2019 and 2020 it dimmed unexpectedly. It would be fascinating if we were able to predict if and when it might go supernova. I hope our new technique contributes to this endeavor and more.”

UNIVERSITY OF TOKYO

Header Image Credit : Andrew Klinger

- Advertisement -
spot_img
Mark Milligan
Mark Milligan
Mark Milligan is multi-award-winning journalist and the Managing Editor at HeritageDaily. His background is in archaeology and computer science, having written over 7,500 articles across several online publications. Mark is a member of the Association of British Science Writers (ABSW), the World Federation of Science Journalists, and in 2023 was the recipient of the British Citizen Award for Education, the BCA Medal of Honour, and the UK Prime Minister's Points of Light Award.
spot_img
spot_img

Mobile Application

spot_img

Related Articles

Stone box containing rare ceremonial offerings discovered at Tlatelolco

Archaeologists from the National Institute of Anthropology and History (INAH) have discovered a stone box containing ceremonial offerings during excavations of Temple "I", also known as the Great Basement, at the Tlatelolco archaeological zone.

Excavation uncovers traces of the first bishop’s palace at Merseburg Cathedral Hill

Archaeologists from the State Office for Monument Preservation and Archaeology (LDA) Saxony-Anhalt have uncovered traces of the first bishop’s palace at the southern end of the Merseburg Cathedral Hill in Merseburg, Germany.

BU archaeologists uncover Iron Age victim of human sacrifice

Archaeologists from Bournemouth University have uncovered an Iron Age victim of human sacrifice in Dorset, England.

Archaeologists find ancient papyri with correspondence made by Roman centurions

Archaeologists from the University of Wrocław have uncovered ancient papyri that contains the correspondence of Roman centurions who were stationed in Egypt.

Study indicates that Firth promontory could be an ancient crannog

A study by students from the University of the Highlands and Islands has revealed that a promontory in the Loch of Wasdale in Firth, Orkney, could be the remains of an ancient crannog.

Archaeologists identify the original sarcophagus of Ramesses II

Archaeologists from Sorbonne University have identified the original sarcophagus of Ramesses II, otherwise known as Ramesses the Great.

Archaeologists find missing head of Deva from the Victory Gate of Angkor Thom

Archaeologists from Cambodia’s national heritage authority (APSARA) have discovered the long-lost missing head of a Deva statue from the Victory Gate of Angkor Thom.

Archaeologists search crash site of WWII B-17 for lost pilot

Archaeologists from Cotswold Archaeology are excavating the crash site of a WWII B-17 Flying Fortress in an English woodland.