Carbon-rich stars steal heavy elements from their low mass companions
Published By : Prameya News Bureau | December 31, 2021 IST
Share
New Delhi, Dec 31: Scientists have long been intrigued by the presence of much higher fraction of elements heavier than iron than is expected in carbon-rich stars. New research by Indian astronomers has now traced its origin to the low mass companions of these stars, from which the materials have been stolen. Though there has been significant progress in understanding the formation and evolution of several chemical elements and their isotopes in the Universe, the origin and evolution of heavy elements, that is, elements heavier than iron, in the Universe is far from being clearly understood. A group of astronomers from the Indian Institute of Astrophysics, Bengaluru, an autonomous institute of the Department of Science & Technology, Govt. of India led by Prof Aruna Goswami and her doctoral students Meenakshi P. and Shejeelammal J. at IIA have analyzed the surface chemical composition of several Carbon Enhanced Metal-Poor (CEMP) stars and have achieved a significant advancement in unraveling this puzzle. This work has been published in ‘The Astrophysical Journal’ recently. CEMP stars are characterized by diverse heavy elements abundance patterns and are primarily classified into four groups, based on which groups of heavy elements are more abundant. These are mostly dwarf stars, sub-giant stars, or giant stars, and stars that belong to these evolutionary stages cannot produce elements heavier than iron. “At the evolutionary stages in which the stars exist, they are not expected to produce heavy elements. However, the surface chemical composition of these stars exhibit abundances of heavy elements those are about 100 to 1000 times higher than that of the Sun. So, we looked for the origin of the observed enhanced abundances of the heavy elements, deriving possible clues from the stellar surface chemical abundance signatures,” Prof. Goswami explained. The team analyzed high quality, high-resolution spectra of the stars acquired using 2-m Himalayan Chandra Telescope (HCT) at the Indian Astronomical Observatory, Hanle, 1.52-m Telescope at the European Southern Observatory at La Silla, Chile, and the 8.2-m SUBARU Telescope at the summit of Maunakea, Hawaiʻi, operated by the National Astronomical Observatory of Japan, to resolve this puzzle. They used elemental abundance ratios of certain key elements such as carbon, magnesium, strontium, barium, europium, lanthanum, etc., as diagnostics that gave important clues to the origin of the enhanced abundances. In two recent papers, both published in the Astrophysical Journal, they have shown that the enhanced heavy elements observed in the CEMP stars are actually produced by their low-mass stellar companions in a phase of evolution called Asymptotic Giant Branch (AGB) and transferred the products to the CEMP stars through various mass transfer mechanisms. The low-mass companions have further evolved to white dwarfs that are no longer detectable. The scientists employed a set of classification schemes and used spectroscopic techniques to examine if the stars show variability in radial velocity and found that most of the stars are indeed binaries. “Analysis have provided further support and confirmed that the companions are of low-mass and also of low-metallicity.” Shejeelammal and Meenakshi pointed out.
News7 Is Now On WhatsApp Join And Get Latest News Updates Delivered To You Via WhatsApp
You Might Also Like
More From Related News
India carries out successful launch of medium-range ballistic missile's new version
Indian IT leaders expect higher budget allocations for GenAI initiatives
BharatPe launches India's first all-in-one payment device
Experience unparalleled features with realme NARZO 70 5G & NARZO 70x 5G
Zomato hikes mandatory platform fee by 25pc
WhatsApp reportedly testing "quick reaction feature for status updates"
Tesla cars to soon have an integrated X experience: Elon Musk
Blue Whale: The dangerous online game behind tragic losses
Dell launches AI-powered laptops, mobile workstations in India
Team of researchers from IIT Roorkee finds giant ancient snake fossil in Gujarat
China hiding military presence in space: NASA Chief
realme P Series to go on sale from April 22
Semiconductor chips driving innovation in tech
Fintech firm BharatPe appoints Nalin Negi as CEO
Edtech major upGrad creates 55k jobs in FY24
IIT Kanpur excels in data science & AI categories in QS World University Rankings
ChatGPT is now more direct and less verbose: OpenAI
Every fourth woman working in India's BFSI sector face gender disparity: Report
India's fintech sector registers 59 pc growth in Q1 2024
AI innovation: Detecting postpartum PTSD risk with new model