Detection of White Dwarf Companions to Blue Stragglers in the Open Cluster NGC 188: Direct Evidence for Recent Mass Transfer

Type Journal Article
Names Natalie M. Gosnell, Robert D. Mathieu, Aaron M. Geller, Alison Sills, Nathan Leigh, Christian Knigge
Publication The Astrophysical Journal Letters
Volume 783
Pages L8
Journal Abbreviation The Astrophysical Journal Letters
Date March 1, 2014
DOI 10.1088/2041-8205/783/1/L8
ISSN 0004-637X
Short Title Detection of White Dwarf Companions to Blue Stragglers in the Open Cluster NGC 188
URL http://adsabs.org/2014ApJ.783L.8G
Library Catalog labs.adsabs.harvard.edu
Abstract Several possible formation pathways for blue straggler stars have been developed recently, but no one pathway has yet been observationally confirmed for a specific blue straggler. Here we report the first findings from a Hubble Space Telescope Advanced Camera for Surveys/Solar Blind Channel far-UV photometric program to search for white dwarf companions to blue straggler stars. We find three hot and young white dwarf companions to blue straggler stars in the 7 Gyr open cluster NGC 188, indicating that mass transfer in these systems ended less than 300 Myr ago. These companions are direct and secure observational evidence that these blue straggler stars were formed through mass transfer in binary stars. Their existence in a well-studied cluster environment allows for observational constraints of both the current binary system and the progenitor binary system, mapping the entire mass transfer history.
Tags BINARIES: SPECTROSCOPIC, ULTRAVIOLET: STARS, blue stragglers, open clusters and associations: individual: NGC 188, white dwarfs
UW-Madison Astronomy Home