Researchers have discovered a vampire star in the star cluster M67, revealing insights into the rejuvenation process of these stars through material transfer from a companion.
Characteristics of Vampire Stars
- Vampire stars, known as blue straggler stars (BSS), defy simple models of stellar evolution and display characteristics of younger stars.
- Their anomalous youth is attributed to rejuvenation through material consumption from a binary stellar companion.
- Star clusters, such as M67, provide an ideal environment to study binary star evolution due to their similar surface chemistry and the presence of a large number of binary stars.
Groundbreaking Discovery
- A team of astronomers from the Indian Institute of Astrophysics (IIA) made a groundbreaking discovery of a vampire star in M67, shedding light on the complex rejuvenation process in a binary system.
- The star showed chemical imprints of recently consumed barium-rich material from its binary companion, detected using the UltraViolet Imaging Telescope on AstroSat.
Surface Composition Analysis
- Spectroscopy was used to study the surface composition of the vampire star, revealing an abundance of heavy elements such as barium, yttrium, and lanthanum.
- These heavy elements are typically found in asymptotic giant branch (AGB) stars, posing a puzzle due to the vampire star’s less evolved nature.
Confirmation of Rejuvenation Process
- The presence of heavy elements in the vampire star’s spectrum indicated pollution from its binary companion, which likely underwent an AGB phase and later became a white dwarf star.
- This discovery confirms that the vampire star acquired polluted matter from its companion, leaving behind a remnant white dwarf.
Unseen Companion and UV Brightness
- The vampire star was found to have a small unseen companion, and its considerable UV brightness was traced back to its hot and small companion, validating the transfer of heavy elements.
Conclusion
The discovery of the vampire star and its rejuvenation process provides rare insights into binary star evolution and poses a mystery regarding the rarity of such chemically polluted systems.
Multiple Choice Questions (MCQs):
- What is the vampire star known as to astronomers?
- A) Black hole stars
- B) Blue straggler stars (BSS)
- C) Red giant stars
- D) White dwarf stars
- Answer: B) Blue straggler stars (BSS)
- What characteristic makes star clusters ideal for studying binary star evolution?
- A) Unique surface chemistry
- B) Large number of single stars
- C) Variable mass ranges
- D) Similar evolution paths
- Answer: A) Unique surface chemistry
- How was the chemical imprint of the consumed material from the vampire star’s companion detected?
- A) UltraViolet Imaging Telescope
- B) Infrared telescope
- C) X-ray telescope
- D) Radio telescope
- Answer: A) UltraViolet Imaging Telescope
- What process is responsible for creating heavy elements in asymptotic giant branch (AGB) stars?
- A) Fusion reaction
- B) Nuclear fission
- C) Neutron capture process (s-process)
- D) Stellar wind
- Answer: C) Neutron capture process (s-process)
- What does the presence of heavy elements in the vampire star’s spectrum indicate?
- A) Internal fusion reactions
- B) Atmospheric pollution from its companion
- C) Natural stellar evolution
- D) Supernova remnants
- Answer: B) Atmospheric pollution from its companion