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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Stars, Interstellar Medium and the Galaxy

Dartmouth Scholarship

2009

And information science

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Full-Text Articles in Physical Sciences and Mathematics

An Oosterhoff Analysis Of The Galactic Bulge Field Rr Lyrae Stars: Implications On Their Absolute Magnitudes, Andrea Kunder, Brian Chaboyer Sep 2009

An Oosterhoff Analysis Of The Galactic Bulge Field Rr Lyrae Stars: Implications On Their Absolute Magnitudes, Andrea Kunder, Brian Chaboyer

Dartmouth Scholarship

We present an analysis of the period-V-amplitude plane for RR0 Lyrae stars (fundamental mode pulsators) with "normal" light curves in the bulge using the MACHO bulge fields. Although bulge globular clusters (GCs) have RR Lyraes that divide into two reasonable distinct groups according to the average period of the RR0 Lyraes, there is no evidence of a gap between Oosterhoff I (OoI) and II (OoII) stars in the bulge field star sample. The majority of the bulge RR0 Lyrae field star population have a difference in period compared to the OoI cluster M3 (Δlog P) that is …


New Neighbors: Parallaxes Of 18 Nearby Stars Selected From The Lspm-North Catalog, Sébastien Lépine, John R. Thorstensen, Michael M. Shara, R. Michael Rich Mar 2009

New Neighbors: Parallaxes Of 18 Nearby Stars Selected From The Lspm-North Catalog, Sébastien Lépine, John R. Thorstensen, Michael M. Shara, R. Michael Rich

Dartmouth Scholarship

We present astrometric parallaxes for 18 suspected nearby stars selected from the LSPM-north proper motion catalog. 16 objects are confirmed to be main-sequence M dwarfs within 16 pc of the Sun, including three stars (LSPM J0011+5908, LSPM J0330+5413, and LSPM J0510+2714) which lie just within the 10 pc horizon. Two other targets (LSPM J1817+1328, LSPM J2325+1403) are confirmed to be nearby white dwarfs at distances of 14 and 22 pc, respectively. One of our targets, the common proper motion pair LSPM J0405+7116E + LSPM J0405+7116W, is revealed to be a triple system, with the western component resolved into a pair …