Detection of White Dwarf companions to Blue Straggler Stars from UVIT observations of M67

N. Sindhu*, Annapurni Subramaniam, Aaron M. Geller, Vikrant Jadhav, Christian Knigge, Mirko Simunovic, Nathan Leigh, Michael Shara, Thomas H. Puzia

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


We investigate the old open cluster M67 using ultraviolet photometric data of Ultra-Violet Imaging Telescope in multi-filter far-UV bands. M67, well known for the presence of several blue straggler stars (BSS), has been put to detailed tests to understand their formation pathways. Currently, there are three accepted formation channels: mass transfer due to Roche-lobe overflow in binary systems, stellar mergers either due to dynamical collisions or through coalescence of close binaries. So far, there had not been any confirmed detection of a white dwarf (WD) companion to any of the BSSs in this cluster. Here, we present the detection of WD companions to 5 bright BSSs in M67. The multiwavelength spectral energy distributions covering 0.12-11.5 μm range, were found to require binary spectral fits for 5 BSSs, consisting of a cool (BSS) and a hot companion. The parameters (Luminosity, Temperature, Radius and Mass) of the hot companions suggest them to be WDs with mass in the range 0.2-0.35 M⊠with Teff ~11000-24000 K.

Original languageEnglish (US)
Pages (from-to)482-485
Number of pages4
JournalProceedings of the International Astronomical Union
Issue number351
StatePublished - 2019


  • open clusters and associations: individual (M67)
  • stars: blue stragglers
  • stars: white dwarfs
  • ultraviolet: stars

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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